'81 J25hp shudder problem (video)

[jasper60103]

Runs like the wind, but just above idle it shudders and vibrates quite a bit.
Notice shuddering at the start. Also at 1:27, 2:23, 3:30.

FYI. New L77JC4 plugs gapped at .30. Also, I tried adjusting idle. It doesn't idle as smooth as I would like. It seems the initial setting works best, 1-1/4 turns out.

What do you think it could be?

Thanks.

http://www.youtube.com/watch?v=X80znB3TMm4



Catch of the week !...

 

[Daviet]

Re: '81 J25hp shudder problem (video)

If it were mine, I would start by pulling the carb and overhaul it, make sure you remove the core plug on top of the carb, and clean ALL passages and orifices.