Engine run and staring problems

[foreverstrung]

Hey All. Been a bit. Got a problem here and would appreciate your thoughts.
I've got a '01 Mercury 200 salt water, carbed 2 stroke. The last couple times out I was only at about 60% power. 28 MPH full throttle. should be 45 MPH full throttle. Have not started it for 2 weeks and today it would not spark at all. Checked primer bulb and gas was flowing though bulb never got hard. New plugs 3 months ago. Rebuilt carbs and fuel pump as well.
     Could it be the fuel lines cracked and getting air? How would I check and locate this possible damaged area? If so, why would I not get any spark? Some gas appeared to be getting to the motor.
appreciate ya

[saltfly]

Unplug your cable harness. Then check your spark. Put a remote switch on your power and the other end on
your coil  to use it in place of your harness switch.  If you have spark, which I think you will. Change your starter switch. Think about it. When you turn off your motor. You ground it out. So you get no spark. When a switch goes bad, it either burns open, which won't turn over your motor, or shorts to ground which will let it turn over, but won't give you spark.  If your stator were to keep you from getting spark. The whole stator would have to burn out. Which can happen, but is unlikelly.

[fitz73222]

Hey All. Been a bit. Got a problem here and would appreciate your thoughts.
I've got a '01 Mercury 200 salt water, carbed 2 stroke. The last couple times out I was only at about 60% power. 28 MPH full throttle. should be 45 MPH full throttle. Have not started it for 2 weeks and today it would not spark at all. Checked primer bulb and gas was flowing though bulb never got hard. New plugs 3 months ago. Rebuilt carbs and fuel pump as well.
     Could it be the fuel lines cracked and getting air? How would I check and locate this possible damaged area? If so, why would I not get any spark? Some gas appeared to be getting to the motor.
appreciate ya

Didn't you have this issue a couple of months ago? I thought it was resolved?

[wingtime]

First thing you check on an outboard is spark and compression.  You may have lost a switch pack and were running on only one bank of cylinders.

As for the primer bulb.  Make sure you hold it with the arrow up to be sure the check valves are fully seating.  They don't have springs and rely on gravity.

Salts suggestion of ruling out the key switch is great advice too since they are prone to failure.

[foreverstrung]

Well I went out there today and confirmed I had spark. I'm still not real sure how to check for compression. Never the less, I checked the fuel lines. Hadn't been started in 2 weeks or so and it's been hot as sin here in Texas. The primer bulb wasn't gettin firm so I checked my filter and fuel lines, check valves etc. I think there may have been some blockage in the fuel line between the tank and primer bulb. Disconnecting the primer bulb and pumping it straight from the tank, I was getting little to no gas. I put a hand pump on it and it started flowing. Hooked it back up and it started pretty nice. Let it idle for a half hour or so as I tidied up and decided to take it out and open her up. She stalled 10 minutes out. Sounded rough. Started up again and headed back, (never did get to open her up), stalled again. Started again, sluggishly both times and limped home. My tank is low, I'll go out tomarrow with a portable tank and see what happens.
     If this is the idle/start issue, which I believe it is, great. But I still expect to be at 60% power or so. I do need to check the switch pack, but checking for spark as I turn it over is a 2 man job right? Unless someone has a way they would care to share. Also, How do I check the compression?

[slvrlng]

Sounds like you have crud in the tank. I had a old boat that would crank fine, rev up at the dock, but as soon as you hit a wave of any size all the sludge would get mixed up and it would shut it down. Then wouldn't crank until I cleaned the filters.

Compression is pretty easy to check, basically crank the motor over 4 times without the plugs in. Here is a link to an exact description.
http://forums.iboats.com/showthread.php?t=391323

[fitz73222]

How did the engine run on a remote 6 gallon tank including a different fuel line? Are you fueling with ethanol based fuel? It is common for older fuel lines to delaminate  internally and break apart causing fuel starvation problems. It may not show up in the filter because the chunks are to large to get into the filter and will lodge at a fuel line connection points and shut the fuel supply off. Your engine does not have switchboxes in the ignition system like older models. The ignition system uses a combination coil and CDI module for each cylinder which was introduced in the '97-'98 model year and has proven very reliable. I doubt compression is the issue. If the engine runs fine on a remote tank with known good fuel then you have a vent problem or a fuel delivery problem in the main fuel system. Lastly, you could have water laden fuel from one of several causes.

[foreverstrung]

I'm not sure of the firing order, but 4 of the 6 cylinders had 60 PSI and the 2 furthast aft, on the motor, left and right, measured 70 PSI. (I pulled all 6 plugs out and checked the compression one cylinder at a time).  I didn't have the right tool to measure the spark, but while idleing, all six plug wires, when removed from the plug, one at a time, gave a nice audible "clicking". Very bright out today. Couldn't see the spark, but I could hear it. Ran it off a porable tank. Dueched the carburater jets with carb cleaner. Put her all back together and let her idle for a half hour or so again. Took her out and on the bay, top speed was only 28 MPH, should be closer to 40 MPH. She stalled. Took about 3 minutes to start her back up and just took her home nice and easy with no issues. Didn't open her up again, but she ran at about 5 MPH with a steady purr, but very reluctantant to hit the gas. Obviously gas is part of the problem, maybe all of it. Does it sound like I might have run some foul gas through the carbs? Maybe let it sit too long, (gas in carbs and fuel lines)? I'm thinking I probably need to rebuild these carbs again and be more careful with my fuel use. Appreciate the help

[GoneFission]

60-70 PSI compression is low for that 2.5L motor.  Should be over 100 PSI - around 120 would be good.  The '91 model 200 2.5 V-6 is considered a desirable motor - the go fast guys find it easy to build up and - as the web site says - scream and fly!  

Sorry to say this, but you've got some problems if 60-70 PSI is an accurate compression number on all 6 holes.    

[fitz73222]

I'm kind of suspicious of your compression readings. I personally haven't seen readings that low and relatively even on all six cylinders. Was there an o-ring present on the compression tester where it screws into the cylinder head? Did you hold the throttle wide open when you were doing the test? If in fact your compression is that low, you have a serious problem. Are you sure this engine isn't overheating? Your hot horn or warning module may not be working. When the engine stalls when you are trying to run at high speed, does it just slow down and stop? When you go to restart is the engine turning over slower than normal? Unless your are ready to pull the cylinder heads and physically inspect each cylinder bore for scoring or excessive carbon build up on the piston domes it may be time to get a second opinion from a certified mechanic. As mentioned, carbon build up can also cause low compression like this because the piston rings are stuck and not seating properly against the cylinder walls. This was a huge problem in the 80's when oil companies were experimenting with various fuel dispersants and lots of powerhead failures from coking as a result but its been many years since the problem was widespread.

[foreverstrung]

There is no o ring on the tester, but the presure stayed consistant until I relieved the pressure manually from the gauge. I did not hold the throttle wide open. I hit the kill switch and just turned her over until the gauge quit climbing

[foreverstrung]

Wanted to add.......This stalling issue is new. The last few times I took her out, the top speed was under 30 mph and she never stalled. I've been distracted here for a bit and she sat, unstarted, for 3 1/2 to 5 weeks. Then she wouldn't start and I noticed the fuel line issues and realized my tank was under a 1/4 full, probably pretty nasty. Stalled 1st time with this nasty gas. Stalled yesterday on a portable tank after running at idle speed for near an hour, opened up to 28 mph for about 3 minutes and then it was like the bottom just feel out of it. Started bach up pretty easy within a couple pf minutes and ran at idle speed all the way home, 20 minutes. If it had ovrheated, I'd be surprised that it started so quick after stalling. I'm hoping that I just didn't do the compression test correctly

[foreverstrung]

Someone else asked about "Throttle wide open", when doing the compression check.  If I have the motor in gear at all, which is also my throttle, the key will not engage. Am I missing something here? Can I open up the throttle on a Morse SL3 controler?
    OK Found the manual for the  Morse shifter/throttle. There is a a safety button in the center of the handle which allows throttle without engaging the gears. Used for warming up etc. I'll go run the compression check again this afternoon with this new knowledge and report back. Appreciate the help. Sorry for the appearence of "Stupid". Gotta start somewhere I suppose.

[Capt. Bob]

Sorry for the appearence of "Stupid". Gotta start somewhere I suppose.

Not hardly.
The "detent" function of a control comes up quite often on this and every other boating forum on the net.
Now you know.

Good luck.

[wingtime]

Are you doing the compression test with the motor cold or warm?  You should do it with the motor warm since that will give you a true idea of the compression with the motor at operating temps.