Trying to Diagnose a Miss - Evinrude 9.5 - Video Included

[bradford0113]

I am trying to diagnose the miss that can be seen / heard in the following video.

The miss only happens at low idle speed; when throttled up, I no longer notice it. Here's the situation... First out, wouldn't idle at all. Removed and cleaned carb which appeared gummed up, then seemed to idle well running in bucket. Compression check top = 65, bottom = 55. Decided to do a decarb before going back out on the lake. Completed decarb process and now this miss shows up at low idle. New compression top = 50, bottom = 50. Appears to have good consistent spark. Could a compression issue be causing this?

Any ideas?

Thanks
~Brad

 

[oldcatamount]

Re: Trying to Diagnose a Miss - Evinrude 9.5 - Video Included

Sounds like a "lean sneeze". Give the low speed needle a quarter turn (or so) counterclockwise, go slow with the needle adjustment, give the motor 15 seconds or so to react to the change. Go a little further if you need to.

 

[bradford0113]

Re: Trying to Diagnose a Miss - Evinrude 9.5 - Video Included

Ok... I'll try that next time I am out.

Should I be concerned about the low even compression readings? I'm wondering if I might have a head gasket issue. Are there any other signs that one could look for to determine if a head gasket is bad?

 

[Chinewalker]

Re: Trying to Diagnose a Miss - Evinrude 9.5 - Video Included

I think your gauge might be off. I don't think your motor would start at all if it were actually 50psi...

As for the kick - it's a lean sneeze, as noted above.

 

[meyerboy]

Re: Trying to Diagnose a Miss - Evinrude 9.5 - Video Included

I have the same motor in the garage, and I agree that the hic-cup is probably running too lean. Be careful when you adjust the low-speed needle, by that I mean look to make sure the cable is turning OK. The carb is in a funny sopot on this block and they used a remote from the faceplate to adjust it. Mine was loose at the neddle and not actually turning anything. Also, I don't ever recommend anything (I leave that to the guys that charge 140 an hour) BUT, I removed the thermostat from mine and improved a lot on the cold and hot idyl.

good luck