Rhojo's '88 Johnson 70's J707TLCCA, updated... reed fix

[Georgie]

Wow.  Good pics and nice work so far, Jon.    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.

[dburr]

That'll teach me to put my glasses on before I look at these pictures, completely missed that half of the reed was GONE

How in the world would a piece that size make it through ? 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?

[Rhojo]

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.



...must...find...the...piece(s)... :batman:

[fitz73222]

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.



...must...find...the...piece(s)... :batman:

Pull the cylinder head...The worst case is it cost you a head gasket if nothing is wrong.

[icemanbryan]

Is it possible that the reed was shattered and blew out the exhaust?

[fitz73222]

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!

[futch13]

Carbs off and peeking inside...I see a broken reed...


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

[fitz73222]

Carbs off and peeking inside...I see a broken reed...


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.

[futch13]

I sure hope not, but that kind of aluminum never bodes well.

[Rhojo]

just found a broken head bolt. This is gonna set me back a little, I don't have the tools for this handy...


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:

[futch13]

just found a broken head bolt. This is gonna set me back a little, I don't have the tools for this handy...


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  

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

[fitz73222]

just found a broken head bolt. This is gonna set me back a little, I don't have the tools for this handy...


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  

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?

[futch13]

Yes, 27+ years Johnrude, Yamaha, Merc, cut my teeth on down draft carbs LOL

[fitz73222]

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!

[futch13]

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     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"