97 evinrude 70hp misfire and wont idle

[aftershock]

I took my 70hp evinrude 2 stroke that i got last year to a marina due to it started to misfire and wont idle. at first it didnt like to idle but as soon as it was off idle it would run fine. it developed a misfire so I took it to the marina to have these issues addressed. they at first said carburetor was the cause and when they dug deeper into the carb they found it was in decent shape. they believe there is a ring siezed and the engine would need rebuilt. my concern is I checked compression across all 3 cylinders and they are all just shy of 100 psi. I work on cars and when a ring is bad in a car engine there is usually a dramatic difference on compression. before I take it for a second opinion any thoughts on if the rings make sense or any ideas on what else could be going on?

 

[saltchuckmatt]

I took my 70hp evinrude 2 stroke that i got last year to a marina due to it started to misfire and wont idle. at first it didnt like to idle but as soon as it was off idle it would run fine. it developed a misfire so I took it to the marina to have these issues addressed. they at first said carburetor was the cause and when they dug deeper into the carb they found it was in decent shape. they believe there is a ring siezed and the engine would need rebuilt. my concern is I checked compression across all 3 cylinders and they are all just shy of 100 psi. I work on cars and when a ring is bad in a car engine there is usually a dramatic difference on compression. before I take it for a second opinion any thoughts on if the rings make sense or any ideas on what else could be going on?

Yeah, seems sketchy.

Post your model number so we know what you have. Any videos of it running? YouTube's are easy to make and send.

What other diagnostics were done?

 

[aftershock]

so I went throught the engine. 110 psi in each cylinder less then 10% loss in leak down. has spark on all 3 cylinders. just rebuild the carbs ( which really didnt need to be done they were clean). im at a loss. cylinder 2 is still misfiring when boats in the water. only other thing I can think of is timing is off.

 

[cyclops222]

Check your linkage on the bad carburetor.Loose, worn out

 

[flyingscott]

Have you tried adjusting the carbs? Are the tops cracked?

 

[saltchuckmatt]

so I went throught the engine. 110 psi in each cylinder less then 10% loss in leak down. has spark on all 3 cylinders. just rebuild the carbs ( which really didnt need to be done they were clean). im at a loss. cylinder 2 is still misfiring when boats in the water. only other thing I can think of is timing is off.

Timing would effected all the cylinders at once so that doesn't make sense.

Have you done a spark JUMP test?
Testers are cheap....look for a 7/16 blue spark.

 

[Crosbyman]

misfiring as in no fuel to burn or misfiring as in no sparks ???

top& bottom carb section small side channel passage feeding fuel to the upper idle circuit and drip holes cleaned out properly ?