1992 Evinrude 25hp Pop/Backfire then stall at idle

[Broadriverboater]

I've got a 1992 Evinrude 2 stroke 25 hp outboard. It will crank pretty easily and runs great, but it won't idle. It backfires and then stalls out every time i leave it to idle within a few seconds. In gear or neutral, either way unless it's revved up pretty high it will pop and stall. Any help is appreciated, I already put new plugs in it.

 

[boobie]

Re: 1992 Evinrude 25hp Pop/Backfire then stall at idle

Sounds like you need some carb work. But first, do a compression test on it.

 

[Broadriverboater]

Re: 1992 Evinrude 25hp Pop/Backfire then stall at idle

I'll clean the carb soon, then. What am I looking for in a compression test?

 

[BonairII]

Re: 1992 Evinrude 25hp Pop/Backfire then stall at idle

I'll clean the carb soon, then. What am I looking for in a compression test?

Ideally, you're looking for all cylinders to be within 10% or so of each other.

 

[Broadriverboater]

Re: 1992 Evinrude 25hp Pop/Backfire then stall at idle

Ideally, you're looking for all cylinders to be within 10% or so of each other.

Alright, I'll have that done. What else could it be?

 

[Haffiman]

Re: 1992 Evinrude 25hp Pop/Backfire then stall at idle

1: Check that thermostat is working and engine reaches operating temp.
2: Check you 'link & synch'. Carb must not start to open until the roller is just on or slightly passed the mark on the cam.
3: Any change when adjusting idle speed mix needle on carb??
4: Hook up a timing light, and add marks on flywheel for cyl 2 at TDC. Check that only one mark is visible when engine is running.