# 4 cylinder

[steve'o']

Well I checked the plug this am, and there is still a bit of discoloration, although it is more brown in color now compared to a black sooty substance. The other 3 plugs are all nice and grey in color. I haven't shot any FI cleaner or compressed air through it yet, and even though # 4 plug is still not the same color as the other 3, the bike seems to run much better and smoother, even at idle. Before at idle the tach needle would jump, almost like a heart beat. Still a bit more investigation and hopefully a valve check in about 3 weeks or so. Thanks for all the help on this issue.

 

[steve'o']

Just one question to those who have put some FI cleaner and pumped compressed air in the mixture screw hole, how much cleaner and how did you apply it, and how much air?

 

[road runner]

Just use carb cleaner.It comes in spray can and has a plastic tube that you can stick in the hole. You don't need a lot, just a few quick shots. Just don't get it on any plastic. When you stick the tube in the air hole, wrap a rag around it so it doesn't spay back at you. Then give it a blast of air from an air hose, with the rag around it again.

 

[dcarver]

F#^&^%$#G #4 mixture screw was way out, 1 1/2 rotations more than the other three, 4 1/2 total turns out,

If the idle air screw was "out" more then the others, then one might conclude more air giving a leaner a/f ratio would have been seen at that cylinder.

You have the opposite going on. Did you blow the passage out with throttle body cleaner and compressed air? I'd do an "unauthorized TB sync" after that. Hope you figure it out, I think your on to something here.

I'll bet the screw was way out because the last jamoke that tried to do a TBS couldn't match that cyl to the others because it was occluded with spooge, so he just cranked it way out and then left it there.

Agree.

 

[Mihalis fjr]

Just use carb cleaner.It comes in spray can and has a plastic tube that you can stick in the hole. You don't need a lot, just a few quick shots. Just don't get it on any plastic. When you stick the tube in the air hole, wrap a rag around it so it doesn't spay back at you. Then give it a blast of air from an air hose, with the rag around it again.

Agree!!It is a must do thing!!I believe this throttle body is a little..- to much...cloged!

 

[steve'o']

Thanks again guys. It's Friday and no NERPT form me, so have a good weekend.