97 evinrude 70hp misfire and wont idle

aftershock

Recruit
Joined
Jul 2, 2025
Messages
1
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

Commander
Joined
Jul 19, 2019
Messages
2,822
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?
 
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