[chbailey]

I have a 97 Evirude motor that was having problems idling and seemed to be bogging down while running wot. I knew I was only getting about half the performance of the motor. I talked to a dealer and they suggested pulling one of the plug wires while running the motor. I pulled the top wire and the motor quit. I pulled the bottom wire and the motor kept running. I put some fuel in a glass jar and I don't see any water in it. I am getting a charge out of the second wire and I replaced the plugs. Same results. Anyone?

[tashasdaddy]

welcome to iboat, it's a 97 what. so you are saying, i think, you have spark on both cylinders, but it is not running on the bottom cylinder. in thats case if would check the compression on both cylinders. not know what motor you have thats as far as i will go.

[chbailey]

It's a 97 Evinrude 2 stroke ESL. I reversed the timing from the power pack and swapped the plug wires so #2 was firing cylinder 1 and the motor still died. So my power pack works fine and cylinder #2 still does not fire. The cyclinder head looks clean. I don't see any pealing paint save the white paint on the bottom half of the head seems to be wearing off. But I would say that is from time and use and not over heating.

Looks like the cylinder head has never been off and a friend of mine suggested pulling the head and seeing if the gasket is shot. Seems logical that the gasket would be bad considering the motor is 10 years old. That would go hand in hand with compression issues.

[tashasdaddy]

what horsepower is it. do a compression check. don't go pulling heads until you know you need to. if you don't do the right troubleshooting all you are doing is wasting time, and money on parts you don't need. a 10 year old motor is not even broking in good.

[chbailey]

It's a 50 HP motor. I can get a compression test done in a couple of days. What are the chances it's a bad cylinder?

[tashasdaddy]

now i have something to work with. the 50 has 2 carbs, it sounds like the bottom carb, is not letting fuel into the bottom cylinder. take some premixed gas in a spray bottle, remove the front of airsilencer, so you can see into the carbs. start the motor, and spray fuel in to the bottom carb. if the engine picks up that's your problem. the float needle in the carb is stuck. very simple fix. to remove the carb, and clean them.

a dead cylinder is not rare on a neglected 10 year old. if it's been run hot, or with a poor fuel oil mix, or run dry, for and extended period. due to a clogged carb.

[chbailey]

The spark plug appears to be wet when I pull it out but I'll try your suggestion too.

[tashasdaddy]

ok wait a minute.
" I reversed the timing from the power pack and swapped the plug wires so #2 was firing cylinder 1 and the motor still died. So my power pack works fine and cylinder #2 still does not fire"

are you saying that the coil on #2 did not fire. if thats the case you need a coil.

[chbailey]

The coil on #2 was firing cylinder #1 but the coil going to #1 (which was #1) still would not fire #2. I'm saying either way, cylinder #2 would not fire even though it had #1's connected which was working. Also, cylinder #1 would fire with #2's coil.

[tashasdaddy]

ok so the coil and the power pack are good. then it's either the carb, or compression. and you said the plug was wet. leads me to want a compression test on both cylinders.

[chbailey]

That what was pretty much led me down the path of the pulling the head. I'll get the test done first before I go through that. Also, I was manually turning the head and it would be firm and a little difficult for the first turn and a little easier for the second and back to firm. So it pretty much seems like the second cylinder.

I'll get the compression test done and go from there.

Thanks for the help, I really appreciate it!!

[tashasdaddy]

pay attention when you pull the head to see if the gasket has blow out marks.

[chbailey]

No blow out marks that I can see. Gasket seems kind of gunky. Should I steel wool it to get it clean and put it back together and see if I get the compression needed? Or replace the gasket first and then put the head back on? Compression chambers look good and when manual turning the fly wheel the cylinders appear to be in normal operation.

[tashasdaddy]

new gasket. then compression test. post results.

[iwombat]

Has this motor ever been decarbed? Could have a set of stuck rings. Could also be a leaky exhaust gasket. Compression numbers should rule both out though.

[chbailey]

New gasket and compression ok. Dismantled carb and cleaned thoroughly and solved the problem. Doing a carb rebuild anyway.