2 cylinders fouling plugs, what next?

I have an '82 Maxim 650 that ran well last season. It was stored for the winter with Stabil for about 3 months. No rust in the tank. The bike will start, but is missing and not running smooth.

Pulled all plugs; 3 and 4 are carbon fouled. 1 and 2 are normal. Checked the coils with voltmeter, and they look ok. The two cylinders fouling aren't on the same coil, so coils don't seem to be at issue. Checked and have spark to all 4 cylinders.

Should I be looking for carb issues next, or are there more electrical things to check. Appreciate any/all help.

Thanks!!

 

Hey Jim;
I would try and drain the carb bowls and see what the fuel looks like.
Maybe try some new plugs.
Is the oil over full?
Maybe try some seafoam.

 

Thanks JD. I did replace the plugs, and oil level is good. Will check the fuel in the bowls next.

 

Hummm.... 3 & 4 fouled. Carbon you say? And it sat all season? With you on this one Rich, clean those carbs out good, pull them to do this. You'll get a much better picture of what is floating around in there and the carbs will get a better cleaning too.

 

Might want to check for exhaust restrictions as well.
ie. mouse nests, etc.

Nachoman

 

Good point Nacho!

 

Thanks everyone... will get on these ideas this week-end.

 

I don't have much to add to this other than an interesting (IMO) observation.

Just his weekend I did a half-assed carb cleaning to try to revive my long-dead Seca (I wish I knew about this board and the mythical XJCD before embarking on this feat - I may have been emboldended to do a full teardown/cleaning). When I put everythign back together, it was running a little better than before, but was still dying out. One thing I noticed was that the headers for #1 and #2 were getting warm, but #3 and #4 were as cold as could be.

I pulled the plugs on 3 and 4 and they were both soaked in gas and heavily blackened. After a little plug cleanup, #4 started hitting, and eventually #3 did, too. It got to where it would idle evenly and rev nicely - though it woudl still cough every once in a whle.

I'm stopping on my way home from work for a full set of new plugs.

Anyway, I just I found it interesting that 3 and 4 were the last to get going, similar to MaximJim. Most likely a coincidence, but maybe there's something to it?