40hp just doesn't want to idle smooth.

I was going to continue with the original thread, but I can't find it.

So here goes...

1993 Evinrude 40hp.

After fixing the ding in the manifold that caused the big vacume leak on the top cylinder, it still idles roughly. Ocassional missfire about every 2 to 5 seconds.

- Still running double mix for break-in (about 4 hours run time now).
- Runs about the same with either top or bottom spark plug wire grounded.
- Spray of fuel mix in carbs from spray bottle causes rpm drop like its choking out.
- New plugs again - still no change.
- Did compression test - 140psi both cylinders.
- Sprayed carb cleaner around both carb gaskets looking for another leak, found nothing.
- Visual spark test while running on one cylinder looks good. Lots of blue spark dancing around electrode.
- Visual inspection of fuel/water separator shows no water in the system.
- Did Synch and Link again.

It runs OK, but I think it should be running smoother.

Any suggestions?

Re: 40hp just doesn't want to idle smooth.

this post doesn't say did you do a carb soaking disassembled and reassemble with a new carb kit and float? but you know to do this.

Re: 40hp just doesn't want to idle smooth.

Yep, carebs were supposed to be rebuilt last fall. Re-did the top carb becasue it was off anyway. It was clean.

Re: 40hp just doesn't want to idle smooth.

TTT

Re: 40hp just doesn't want to idle smooth.

Latest update:

Decide to check timing using the Joe Reeve method. Check the linkage setup and it is for the commercial 48/50 spec, not the 40 spec for my model. Timing is too advanced. So I re-do the Sunch and Link and check timing. And its registering correctly,

When started, it idles Ok, minor carb adjustments and its running much better.

I'm happy.