Classic AquaSport
Aquasport Mechanicals - things that need a wrench, screwdriver or multimeter => Engines & engine woes => Topic started by: Rhojo on October 30, 2013, 03:03:34 PM
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I wanted to go ahead and start this thread even though I don't have everything ready for posting. I'll be adding info, pics and hopefully some video after this weekend.
Brief history:
These are VRO motors but it is disabled, I mix my own gas and I'm a bit anal about my mix, I use one of the seachoice measuring botles and I make sure I'm looking at the 1:50 marks.
These are '88 models as mentioned however I have had a professional do a motor and powerhead swap on the port side motor. So the port side is an '86 midsection and lower unit with my good '88 powerhead swaped onto it. It runs the very best of the two. Just prior to the engine swap I had the same pro rebuild all six carbs. I installed new air cleaner gaskets. The corks ones on the air handlers, both the ones that seal up the air cleaner cover and the ones that go between the carbs and the back of the cleaners. I have new in-line fuel filters under the cowls as well as a clean water/fuel seperator every season. No water in my tank at the moment. All of this has been done over the last two seasons. I never run ethanol without running Startron fuel treatment, never. I've only had non-ethanol gas in the boat once and that was 35 gals of 93 octane in Southport this past weekend. The ran perfectly with this one exception, the starboard motor. It has always been a little sluggish compared to the port side.
I can run them one at a time on the muffs and all seems well. Good throttle response even from the starboard, although I don't rev it much at all. Just take it through the motions prior to launching at the lake. As soon as we get in the water, under load, the starboard engine likes to stall between gears and when I'm getting out of the hole the rpm's are much slower on starboard side to come up.
If I run the starboard engine on the muffs and get under the cowl and take the air cleaner off at idle I have fuel mist coming out the front of the middle carb, a very fine fuel mist. It will even collect in the air cleaner and over the course of a day running the motor will get black carbon on the exterior built up. I do have good and new plugs. I check them and my filters regularly. My fuel lines are in good condition.
I'm going to get some video of the engines on the muffs in the driveway and some video of us in a hole shot on the lake.
I'm looking forward to what all of you guys have to say...
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Me, Georgie, and Debur are on the starting line... I already have 3 possible causes in mind. But I should let my OMC brethren have two seconds out of the tree!
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Jon, quick question. How does the idle speed compare between engines? On the starboard engine that dies when shifting...may be something as simple as knocking the idle up 100 rpm's.
My little Mercs, Farley set up to idle @ 850 RPM. After putting around 60 hours on them, the starboard engine had backed off to 600 at idle. Some of it may have had to do with the throttle linkage slipping at the helm. It would sometimes cut off going into forward from neutral. Got a little more pronounced in that 37 degree weather Saturday morning.
Bumped it back up to 850 Sunday night...she's running like a champ again.
Edit: Double post, sorry about that. But mine didn't count...once you run black you'll never go back.
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Jon when the carbs were done was the reed block checked? Does the mist look like it is pulsing? Just odd that vapor is coming out and not being drawn in... :scratch:
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Jon, quick question. How does the idle speed compare between engines? On the starboard engine that dies when shifting...may be something as simple as knocking the idle up 100 rpm's.
My little Mercs, Farley set up to idle @ 850 RPM. After putting around 60 hours on them, the starboard engine had backed off to 600 at idle. Some of it may have had to do with the throttle linkage slipping at the helm. It would sometimes cut off going into forward from neutral. Got a little more pronounced in that 37 degree weather Saturday morning.
Bumped it back up to 850 Sunday night...she's running like a champ again.
Edit: Double post, sorry about that. But mine didn't count...once you run black you'll never go back.
Both idle about the same, less than 1000 rpm but more than 800, I'll check it.
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Jon when the carbs were done was the reed block checked? Does the mist look like it is pulsing? Just odd that vapor is coming out and not being drawn in... :scratch:
No mention of the reed block from the previous mechanic so I don't think he did anything there. Although he did say he did a thorough check on the whole engine. The mist doesn't seem to pulse, just a steady fog machine type mist but not that heavy.
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Jon when the carbs were done was the reed block checked? Does the mist look like it is pulsing? Just odd that vapor is coming out and not being drawn in... :scratch:
I was thinking the same thing but if she isn't coughing back through the carb it's probably not a chipped or stuck reed valve. I was thinking that the float level is set too high in that carb and fuel is percolating up the high speed nozzle at idle and loading up in the venturi causing the mist condition. This could also cause the engine to bog on take off because it's loaded up in that cylinder and runs OK once she is cleared out. I found more often than not that the engine needs to be "set up" correctly before you can really start to understand whats going on. That means base idle timing, throttle pick-up position and max timing including a compression test done correctly.
A more sinister issue inherent with this engine design exclusively was worn lambert (spelling) seals in the block. These were machined grooves in the block between each crank journal that was designed to keep cylinder pulses isolated from one another during intake and compression rotation of the crank. When these seals get worn the pulses start to invade each other during the vacuum and pressure cycles and the engine will not idle smoothly, will stall and bog on take off. There is no repair for the condition. If the engine idles reasonably well on the muffs out of water but runs poorly in the water with back pressure this can be a sign. Lets hear the video and see if it gives us any clues.
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Jon when the carbs were done was the reed block checked? Does the mist look like it is pulsing? Just odd that vapor is coming out and not being drawn in... :scratch:
I was thinking the same thing but if she isn't coughing back through the carb it's probably not a chipped or stuck reed valve. I was thinking that the float level is set too high in that carb and fuel is percolating up the high speed nozzle at idle and loading up in the venturi causing the mist condition. This could also cause the engine to bog on take off because it's loaded up in that cylinder and runs OK once she is cleared out. I found more often than not that the engine needs to be "set up" correctly before you can really start to understand whats going on. That means base idle timing, throttle pick-up position and max timing including a compression test done correctly.
A more sinister issue inherent with this engine design exclusively was worn lambert (spelling) seals in the block. These were machined grooves in the block between each crank journal that was designed to keep cylinder pulses isolated from one another during intake and compression rotation of the crank. When these seals get worn the pulses start to invade each other during the vacuum and pressure cycles and the engine will not idle smoothly, will stall and bog on take off. There is no repair for the condition. If the engine idles reasonably well on the muffs out of water but runs poorly in the water with back pressure this can be a sign. Lets hear the video and see if it gives us any clues.
good stuff right there, ok I'll get the vid, both in the muffs and in the water.
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Here is the video:
starboard on the muffs
http://www.youtube.com/watch?v=5D53yWu6e6M&feature=youtu.be
from idle
https://www.youtube.com/watch?v=Pg6CDXOLtCE
from a dead start
http://www.youtube.com/watch?v=I18hKGgIgh4&feature=youtu.be
:)
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Hey Jon,
Sorry for the delay. Been on vacation in Key West since Wednesday... :drunken:
That first link is an EXCELLENT video and shows quite a bit of pulsing backpressure pushing a signficant amount of fuel back through the middle carb throat. She's certainly not going to run well with that happening and stalling at idle or while shifting would be a very typical symptom. That amount of reverse air movement simply shouldn't happen if the reed box is functioning properly. I imagine once the engine gets up and going, the increased volume of air being pulled through the carb at higher RPM's diminishes the degree of fault in the cylinder's combustion by a significant percentage, so it probably runs much closer to normal at cruising speed and above. Fitz is right that it will help to narrow down the possibilities if you can at least verify that some basic tuning elements like timing and jets are all consistent between engines and carbs respectively. I could be wrong since I'm unfamiliar with the Lambert seal condition he mentioned, but any exchange of vapors between combustion chambers would probably cause BOTH affected cylinders to run poorly. The video you posted seems to show the problem is very much isolated to the middle cylinder. There's a chance you may be able to see an improperly seated reed or an obstruction by taking the carbs off, but if it's not obvious you'll most likely need to take off the intake manifold too in order to properly inspect. Not sure if that'll require powerhead removal on your 3-cyl OMC's b/c I've never worked any of 'em.
Hope this helps and keep us posted as you work through your diagnostics. Curious what the others will say after seeing the videos.
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Well there is no question that crankcase pressure is migrating back through the reeds. Can't say I ever saw one that bad that wasn't coughing like crazy. At full throttle does that engine turn the same RPM's as the other? Do a compression test next and see if any of the cylinders are low. It may have swallowed a piece of reed valve. This could also be as simple as a piece of gasket material from the carb rebuild has lodged in one of the reeds and is holding it open. Either way, if a compression test does not show and issue you are going to have to pull the reed cages and have a look. You have the newer style lost foam block after '85 so you may be able to pull the reeds without removing the powerhead. I will check and let you know.
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Well there is no question that crankcase pressure is migrating back through the reeds. Can't say I ever saw one that bad that wasn't coughing like crazy. At full throttle does that engine turn the same RPM's as the other? Do a compression test next and see if any of the cylinders are low. It may have swallowed a piece of reed valve. This could also be as simple as a piece of gasket material from the carb rebuild has lodged in one of the reeds and is holding it open. Either way, if a compression test does not show and issue you are going to have to pull the reed cages and have a look. You have the newer style lost foam block after '85 so you may be able to pull the reeds without removing the powerhead. I will check and let you know.
I looked at the powerhead schematic and it looks good to try to do this without pulling the powerhead.
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Thanks fellas, I'll check my compression and report back. :salut:
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Compression test results:
Cyclinder #1 (Top)-105
Cyclinder #2 (middle)-100
Cyclinder #3 (bottom)-105
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Right on! :thumright: At this point I gotta believe the problem has something to do with the reeds, although reed problems aren't the most common problem in the outboard world. Just can't think of another reason for THAT much fuel to be spitting back out of the carb. :scratch:
Either way, if a compression test does not show and issue you are going to have to pull the reed cages and have a look.
Time to break out the tools. :twisted:
I looked at the powerhead schematic and it looks good to try to do this without pulling the powerhead.
Assuming Farley's right, this makes the job quite a bit easier. Do you have a service manual?...or at least a good parts schematic to follow?
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Right on! :thumright: At this point I gotta believe the problem has something to do with the reeds, although reed problems aren't the most common problem in the outboard world. Just can't think of another reason for THAT much fuel to be spitting back out of the carb. :scratch:
Either way, if a compression test does not show and issue you are going to have to pull the reed cages and have a look.
Time to break out the tools. :twisted:
I looked at the powerhead schematic and it looks good to try to do this without pulling the powerhead.
Assuming Farley's right, this makes the job quite a bit easier. Do you have a service manual?...or at least a good parts schematic to follow?
Thanks for the input G!
I do have a manual to consult. :salut:
OK, I'm going to pull the carbs and intake manifold, that's going to mean a new intake gasket and probably carb gaskets as well? :scratch: Then I'll get to see the reed block. I have it on good authority (Thanks Lewis! :thumright: ) that if I need to replace reeds that I should go with the dual stage reeds from Boyesen http://www.boyesen.com/OUTBOARD. The difference is night and day according to Lew. Anyone else had expierence with these? Of course, if I do this to one of the twins I can't leave the other out in the cold so I will consider doing it to both, one at a time but collecting all the necessary parts at once.
8)
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that's going to mean a new intake gasket and probably carb gaskets as well?
Yup. Pretty minor cost, just make sure you're careful removing the old gasket and preparing the surfaces for reassembly. Use sealant only when instructed by OMC. Fingers crossed you'll find an obvious issue in the middle of your reed block.
RE: Boyesen, I have a set and have researched them like crazy but I haven't installed them yet. I've read many positive reviews, and it sounds like Lew has had positive experience, but then my local OMC mechanic who has owned the best OMC shop in town for 30+ years and used to race these engines all the time says not to use 'em, so to each his own I guess. :scratch: Since it appears you can replace yours without removing the entire powerhead, and since failed boyesen reeds don't chew up your pistons/rings like the steel ones can, I'd say go for it. If you're unhappy or they fail, you can just pull them back off and reinstall the steel ones. Make SURE you follow all OMC and boyesen installation instructions precisely. :salut:
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I've run Boyesen reeds on hopped up engines before and really didn't see any benefit besides the fact the engine can swallow them and live through it. The fact is that they will wear out; I've seen it. They are basically fiberglass and you will be replacing them again at some point. Factory reads are cheap and available. One other thing Jon; when you did the compression test, did you turn the engine over no more than 5 compression strokes with the throttle butteries held wide open or just crank it until the compression gage stopped moving?
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I've run Boyesen reeds on hopped up engines before and really didn't see any benefit besides the fact the engine can swallow them and live through it. The fact is that they will wear out; I've seen it. They are basically fiberglass and you will be replacing them again at some point. Factory reads are cheap and available. One other thing Jon; when you did the compression test, did you turn the engine over no more than 5 compression strokes with the throttle butteries held wide open or just crank it until the compression gage stopped moving?
Not more than 5 turns :thumleft: , that's what I did. I did not do anything with the throttle butteries. What is that? :shock:
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Compression is all about air in and air out. By opening the throttle butterflies wide open, you allow the engine to suck in more air and hence it can actually raise the compression but for this excersize as long as it's even, we're OK
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Compression is all about air in and air out. By opening the throttle butterflies wide open, you allow the engine to suck in more air and hence it can actually raise the compression but for this excersize as long as it's even, we're OK
Makes sense. :)
Thanks Farley!
OK, I'll post my findings when I get the carbs and intake off!
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Another source for reeds is Chris Carson marine. http://www.chriscarsonmarine.com/reed-valves.htm
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I've read several studies on different reed setups and most find very little difference in performance of aftermarket reeds compared to factory original. Rubber-coated reeds seem to idle a little better, and (as has already been said) fiberglass reeds will not destroy an engine if they break. But it's rare that factory reeds break unless something else causes it, and both fiberglass and rubber-coated reeds do wear... Think about the scientific method here of only changing one thing at a time - if you change several things and the problem is fixed - you don't really know which thing fixed it...
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OEM reeds, pretty cheap.
http://www.marineengine.com/newparts/pa ... OMC0313420 (http://www.marineengine.com/newparts/part_details.php?pnum=OMC0313420)
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Carbs off and peeking inside...I see a broken reed...
(http://www.classicaquasport.com/gallery/data//684/Camera_dump_11-16-2013_060.jpg) (http://www.classicaquasport.com/gallery/showphoto.php?photo=8403&title=camera-dump-11-16-2013-060&cat=684)
Having trouble getting the pics from the album to show in the post, here is a link to the album...
http://www.classicaquasport.com/gallery/showgallery.php?cat=684
My question now is where is the rest of that reed and what do I do about it?
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When you get the reed block out Jon you may find that the reed is torn/cracked and all the pieces are still there.. I am going to cross the chicken bones and hope for that. GOOD find :cheers: .
If stuff is missing, a bright light and a small mirror is a place to star.t.
Farley, what say you?
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Carbs off and peeking inside...I see a broken reed...
(http://www.classicaquasport.com/gallery/data//684/Camera_dump_11-16-2013_060.jpg) (http://www.classicaquasport.com/gallery/showphoto.php?photo=8403&title=camera-dump-11-16-2013-060&cat=684)
Having trouble getting the pics from the album to show in the post, here is a link to the album...
http://www.classicaquasport.com/gallery/showgallery.php?cat=684
My question now is where is the rest of that reed and what do I do about it?
It swallowed it. Now I have seen engines swallow a reed and never touch a thing on the inside, however yours is a big chunk. We did the compression test to verify there wasn't major damage assuming it ate the reed, but a cylinder leakdown test is the best way to determine if the rings are actually sealing and able to hold pressure. But to truly verify no damage has occured, it's time to pull the cylinder head and visually inspect the cylinders and ports for damage. It is very rare for this to happen on a "fishing" engine and is more typical on 6500+ rpm HO engines, hence the composite reeds necessity. The head is easy to pull. disconnect the temp switch wire and just remove the outer perimeter larger bolts. I'm pretty sure there are no water cover bolts and plate since you have the lost foam cast cylinder head assuming a 1985 or newer engine. Take the bolts out and tap the cylinder head with a block of wood and a hammer to break the gasket seal; it may take several good raps to break it loose then take a look.
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A little help. Hopefully the missing piece is sitting right on top of one of the ports.
(http://www.classicaquasport.com/gallery/data//684/Camera_dump_11-16-2013_081.jpg) (http://www.classicaquasport.com/gallery/showphoto.php?photo=8405&title=camera-dump-11-16-2013-081&cat=684)
(http://www.classicaquasport.com/gallery/data//684/Camera_dump_11-16-2013_097.jpg) (http://www.classicaquasport.com/gallery/showphoto.php?photo=8407&title=camera-dump-11-16-2013-097&cat=684)
(http://www.classicaquasport.com/gallery/data//684/Camera_dump_11-16-2013_106.jpg) (http://www.classicaquasport.com/gallery/showphoto.php?photo=8408&title=camera-dump-11-16-2013-106&cat=684)
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Oh dear, well I didn't see the piece or any fragments at teardown so let me go back and look a little closer :scratch:
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Interesting, look at the stress cracking on the reed cage face in the area where the reed contacts the cage. This may be the reason why the reed broke. The cage may have worn to the point that the reed petal started landing against the cage on one side of the petal and eventually split it in half. Look at the casting quality of that cage compared to the other two. Looks like a metallurgy issue with that cage. Fascinating...
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Wow. Good pics and nice work so far, Jon. :thumright: Hopefully you can find the entire chunk wedged in a corner or stuck crosswise preventing it from moving into the cylinder, perform a minor extraction, and escape this interesting "episode" unscathed. I'm optimistic given your compression readings. Fingers crossed. Part of me is even relieved from a diagnostic standpoint that you're DONE finding the entire problem and now you can move on to FIXING said problem. Not much more frustrating than progressing through your best 5 diagnostic ideas and having none of them actually be the problem.
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That'll teach me to put my glasses on before I look at these pictures, completely missed that half of the reed was GONE :shock:
How in the world would a piece that size make it through :scratch: ? That is assuming it came off as one piece. It almost looks like the reed split in half and the piece that remained twisted and jammed itself in the cage.
When you separate that Jon, go slow and look closely at the base of the reed, you may be able to see what happened there.
Is there any evidence of pieces in the crankcase?
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I haven't found a piece of it yet...
A good led flashlight and turning the motor by hand I can't see anything in the crankcase. Through the plug hole I can't see any severe scoring.
This is crazy but I can see an impact mark on the backside of the reed, that is the mark is on the crankcase side of the reed.
(http://www.classicaquasport.com/gallery/data//684/Camera_dump_11-16-2013_106.jpg) (http://www.classicaquasport.com/gallery/showphoto.php?photo=8408&title=camera-dump-11-16-2013-106&cat=684)
...must...find...the...piece(s)... :batman:
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I haven't found a piece of it yet...
A good led flashlight and turning the motor by hand I can't see anything in the crankcase. Through the plug hole I can't see any severe scoring.
This is crazy but I can see an impact mark on the backside of the reed, that is the mark is on the crankcase side of the reed.
(http://www.classicaquasport.com/gallery/data//684/Camera_dump_11-16-2013_106.jpg) (http://www.classicaquasport.com/gallery/showphoto.php?photo=8408&title=camera-dump-11-16-2013-106&cat=684)
...must...find...the...piece(s)... :batman:
Pull the cylinder head...The worst case is it cost you a head gasket if nothing is wrong.
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Is it possible that the reed was shattered and blew out the exhaust?
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Yep, thats after it makes through the port in the piston skirt, the transfer port, takes a 90 degree turn, does a 360 swirl with fuel charge (looper), gets compressed, fired and out the exhaust port; another 90 degree turn without touching anything!
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Carbs off and peeking inside...I see a broken reed...
(http://www.classicaquasport.com/gallery/data//684/Camera_dump_11-16-2013_060.jpg) (http://www.classicaquasport.com/gallery/showphoto.php?photo=8403&title=camera-dump-11-16-2013-060&cat=684)
Having trouble getting the pics from the album to show in the post, here is a link to the album...
http://www.classicaquasport.com/gallery/showgallery.php?cat=684
My question now is where is the rest of that reed and what do I do about it?
That "puddled aluminum" in the reed block looks more like "dust" from a scored piston, not bad machining. Like the reed stuck against the piston skirt and rubbed the aluminum off transferring back thru the broken reed. Kind of looks likes a detonated piston does just on the back side instead of the firing chamber. Unfortunately being a looper you can't pull an intake plate or exhaust cover to visually inspect.
Just my .02
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Carbs off and peeking inside...I see a broken reed...
(http://www.classicaquasport.com/gallery/data//684/Camera_dump_11-16-2013_060.jpg) (http://www.classicaquasport.com/gallery/showphoto.php?photo=8403&title=camera-dump-11-16-2013-060&cat=684)
Having trouble getting the pics from the album to show in the post, here is a link to the album...
http://www.classicaquasport.com/gallery/showgallery.php?cat=684
My question now is where is the rest of that reed and what do I do about it?
That "puddled aluminum" in the reed block looks more like "dust" from a scored piston, not bad machining. Like the reed stuck against the piston skirt and rubbed the aluminum off transferring back thru the broken reed. Kind of looks likes a detonated piston does just on the back side instead of the firing chamber. Unfortunately being a looper you can't pull an intake plate or exhaust cover to visually inspect.
Just my .02
Could be... Either way its not good. Hopefully Jon is pulling the cylinder head off to confirm.
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I sure hope not, but that kind of aluminum never bodes well.
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just found a broken head bolt. This is gonna set me back a little, I don't have the tools for this handy...
(http://www.classicaquasport.com/gallery/data//684/thumbs/Camera_dump_11-17-2013_002.jpg) (http://www.classicaquasport.com/gallery/showphoto.php?photo=8410&title=camera-dump-11-17-2013-002&cat=684)
OK, I'm going to increase my beer flow for today now, there are a couple of races going and some football. I need to soak...start my parts list...
:rambo:
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just found a broken head bolt. This is gonna set me back a little, I don't have the tools for this handy...
(http://www.classicaquasport.com/gallery/data//684/thumbs/Camera_dump_11-17-2013_002.jpg) (http://www.classicaquasport.com/gallery/showphoto.php?photo=8410&title=camera-dump-11-17-2013-002&cat=684)
OK, I'm going to increase my beer flow for today now, there are a couple of races going and some football. I need to soak...start my parts list...
:rambo:
I have already open the IV all the way celebrating the Bucs actually showing up and playing well :cheers:
Sux about the bolt. We have started using a product from MarPac called corrosion inhibiter. It is supposed to be used to prevent corrosion but we have found it's a miracle spray as a penetrant. And as a bonus, it smells good also LOL
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just found a broken head bolt. This is gonna set me back a little, I don't have the tools for this handy...
(http://www.classicaquasport.com/gallery/data//684/thumbs/Camera_dump_11-17-2013_002.jpg) (http://www.classicaquasport.com/gallery/showphoto.php?photo=8410&title=camera-dump-11-17-2013-002&cat=684)
OK, I'm going to increase my beer flow for today now, there are a couple of races going and some football. I need to soak...start my parts list...
:rambo:
I have already open the IV all the way celebrating the Bucs actually showing up and playing well :cheers:
Sux about the bolt. We have started using a product from MarPac called corrosion inhibiter. It is supposed to be used to prevent corrosion but we have found it's a miracle spray as a penetrant. And as a bonus, it smells good also LOL
Hey Futch...Are you in the business?
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Yes, 27+ years Johnrude, Yamaha, Merc, cut my teeth on down draft carbs LOL
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Ahh yes the early V4's, ever due a side draft 100? Carl Kiekhafer would have been proud of that engineering feat. Must have been a Charlie Strang legacy from Mercury after he moved to OMC! Welcome, glad to have you on our site!
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Thanks fitz, the down drafts were over with when I started, but there were a lot of them still on the river in St Louis when I got out of the Air Force and started in the business. Don't ask going from planes to boats :shock: Mercury was having problems with their oil gelling in the autoblends and VRO had just come on the market. Should give an indication of when I started.
Sorry to hijack rhojo's thread :pirat: will move to "Chum"
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Futch, you in our neck of the weeds? Bucs actually looked pretty damn good today... :thumright:
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Futch, you in our neck of the weeds? Bucs actually looked pretty damn good today... :thumright:
Yes, over in Lakeland/Mulberry Was actually able to sit thru a whole game this year :)
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Futch, you in our neck of the weeds? Bucs actually looked pretty damn good today... :thumright:
Yes, over in Lakeland/Mulberry Was actually able to sit thru a whole game this year :)
Futch, glad you're here.
You mentioned hijacking. This thread is like most. Topic...then small chit-chat among ourselves...then back on topic.
All good. Great input on your end, particularly regarding the casting.
Jon, pulling for you and watching with interest :salut:
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Mulberry...home of Comcar...
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Jon,
I'm no good with the loopers, but it looks like only the head of that bolt is broken off? If so, can't you remove all the other head bolts and any wires, coils, or other obstructions, then tap the cylinderhead from the sides to break the gasket seal by allowing the head to pivot on the one broken bolt? If so, and if you're careful with penetrant and heat, you can probably get the head off and still have plenty of exposed shank left to remove what's left of the bad bolt. Would only cost you the price of a single replacement head bolt. :idea:
Had to do that very same thing on the crossflow I rebuilt for my father. This would save you the ENORMOUS headache of drilling and tapping/helicoil/oversizing, welding on a nut as a new screwhead etc. Just a thought.
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Jon,
I'm no good with the loopers, but it looks like only the head of that bolt is broken off? If so, can't you remove all the other head bolts and any wires, coils, or other obstructions, then tap the cylinderhead from the sides to break the gasket seal by allowing the head to pivot on the one broken bolt? If so, and if you're careful with penetrant and heat, you can probably get the head off and still have plenty of exposed shank left to remove what's left of the bad bolt. Would only cost you the price of a single replacement head bolt. :idea:
Had to do that very same thing on the crossflow I rebuilt for my father. This would save you the ENORMOUS headache of drilling and tapping/helicoil/oversizing, welding on a nut as a new screwhead etc. Just a thought.
The goal is to get the head off to see if this thing is toast or not. Take the rest of the headbolts out and see-saw the head off around the remaining stud. You may need to heat up the head around the stud to get the salt to pop loose on the shoulder. The stud will come out with Mapp gas and a pair of vice grips.
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Jon,
I'm no good with the loopers, but it looks like only the head of that bolt is broken off? If so, can't you remove all the other head bolts and any wires, coils, or other obstructions, then tap the cylinderhead from the sides to break the gasket seal by allowing the head to pivot on the one broken bolt? If so, and if you're careful with penetrant and heat, you can probably get the head off and still have plenty of exposed shank left to remove what's left of the bad bolt. Would only cost you the price of a single replacement head bolt. :idea:
Had to do that very same thing on the crossflow I rebuilt for my father. This would save you the ENORMOUS headache of drilling and tapping/helicoil/oversizing, welding on a nut as a new screwhead etc. Just a thought.
The goal is to get the head off to see if this thing is toast or not. Take the rest of the headbolts out and see-saw the head off around the remaining stud. You may need to heat up the head around the stud to get the salt to pop loose on the shoulder. The stud will come out with Mapp gas and a pair of vice grips.
Let me get this head off as soon as I can. Not sure I can do much on it during the week but we'll see.
I remembered overnight that I do have a spare powerhead, it is seized and does have some missing parts such as the carbs but I know the head was on it and maybe the intake is there as well. I think it is. If I need a reed cage I may have it. I'll have to check that powerhead out a bit closer. I'm not really trying to save money on misc. parts yet but it may help me out.
Thanks for the input fellas and keep your fingers crossed for me! I'll keep updating... :eye:
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welding on a nut as a new screwhead etc. Just a thought.
Saw that done once on one of those car building TV shows. The guy MIGed a nut on a busted stud on a transmission then broke it off 3 times, the 4 time the stud came out.
I thought that was a GREAT idea..
Now I am wondering, most likely over thinking it.. If the nut is MIG/TIG /Sticked on is there a chance that at the same time you are spot welding (as the stud grounds to the block where the welding ground is) the offensive stud to the block? With a steel stud and aluminum block I think it'd be a non issue but how 'bout steel in steel?
I'd braze the nut on in an eyeblink, all that concentrated heat and no arc to worry about..
Am I overthinking it? :scratch:
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Saw that done once on one of those car building TV shows. The guy MIGed a nut on a busted stud on a transmission then broke it off 3 times, the 4 time the stud came out.
I think I saw the same show! :afro: It was on the Gas Monkey show...
I hope it doesn't come to that, I'm no welder!
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You got it Jon! :mrgreen: I just couldn't remember :roll: it was a slow day at work..
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No need to get nutty about this. The stud is broken off flush with the block so it would be a challenge to get the stud clean enough for any weld to stick to it anyway, plus you would wind up damaging the cylinder head bolt surface trying to grind on it. Its stuck on the shoulder like 99% of them are from water passage salt migrating into the shoulder. Play the metallurgy game, aluminum expands at 3X the rate of steel so just take a Mapp gas torch and heat up the aluminum around the bolt and it will expand away from the bolt and the salt will start to pop out of the shoulder area as you rotate, tap, wiggle the head off. Nice of someone to leave that mess for you. Looks like its been broke for a while as evidenced by the rust on the bolt end. This is standard jackleg mechanic work trying to wrench :*: apart without patience or knowledge of what they're doing and leaving the customer with the problem. I learned a long time ago that if you can't break the bolt loose with one hand, its stuck. Put the wrench on it and bang with your palm. Same goes for water pump bolts with a 1/4 inch drive ratchet. The extra 5-10 minutes of adding a little heat can save hours of drilling and tapping. I grew up and still live with saltwater engines and always approach disassembly assuming all the bolts are stuck. I'm sure Futch can attest.
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100% Farley. Also a 1/4 drive impact worked slowly both ways speeds the process up greatly.
If anyone is in the market for battery powered tools, ck out Milwaukee's 12v line. I have converted all my snap-on, bosch, Mac tools over to them. They are light, strong, and the batteries last for ever. Their impact is the one I'm talking about. It has 2 different torque settings
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Bump... Jon, did you get the cylinder head off?
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I broke another head bolt so the head is not off yet. I'm dead in the water until I get these out.
bleh :puker: :pukel:
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:shock: :pale: :evil:
Sorry Jon.... Those bolts are supposed to be pretty dang tough! Did the heads pop off the second one the same way as the first one?
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:shock: :pale: :evil:
Sorry Jon.... Those bolts are supposed to be pretty dang tough! Did the heads pop off the second one the same way as the first one?
Pretty much. Soaked in PB for 24 hours and I had a map torch on it for some heat and I still broke it right off. :shaking:
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I thought it was time for an update on this thread. I'm for the long absence but it has been just crazy around the house and work. We've had a busy spring.
I did get the head off, broke 3 more bolts in the process and totally destroyed the head. That head costs about $500 IF you can find one. I already had a spare off my parts motor. That's 5 broken head bolts out of the 14 that hold it on. Of those 5 bolts, 2 would not budge. Welded nuts on the studs and they just continued to break off. Bit the bullet and drilled them out. Got one of those re-tapped well enough to proceed and while re-tapping the second bolt broke the tap off in the hole! OUCH! That's case hardened steel. :scratch: Well, using a couple different center punches broke the tap up into little pieces, one by one and finally got almost all of it out.
Then decided that the only way to move on was to repair with helicoils. That went really well and I am pleased with the results. Got the new head back on and went with a slightly, very slightly, shorter bolt on that one hole with a tiny bit of the tap still in it.
I forgot to mention that after I got the old head off I found no signs of the split reed, no signs of scoring on the cylinder walls so I put it all back together. I used a leaf plate and reed off my parts motor as the broken one had some issues where the reed was impacted and split. A new reed would not have fixed that.
After I got it all back together it was time to fire it up! So far it runs really well on the muffs, what a relief! :cheers: Both motors are almost ready to go for the season. I am changing gear oil in the lower units over the weekend and we hope to splash sometime this weekend as well.
Thanks for all the support and guidance on this issue. It was a huge undertaking for me. There were times, of course, that I felt it would never run again. I was worried about the length of time that had passed since I started this project last year. That's one nice thing about the twins, I had a perfect example hanging on the port side of the transom! Thanks again to you all!!
See you on the water, good fishing, and everyone have a safe holiday this weekend!! :salut:
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Sounds like just about everything that coulda gone wrong with that project did go wrong. :shock: :evil:
Ecstatic to hear you persevered and now have her up and running again! Let us know how the on-water test goes! :cheers: