One carb not consistent

[josephjhaney]

I have one carb/cyl that's not firing regularly, pops at times, if I hit it then let off it will backfire a bit. Had the carbs synced last year by the dealer, after I had done it, dealer said they were all outta whack, not sure how since my meter had them all pretty darn close, but figured he's the pro, and it did run a lot better, but that carb/cyl is still not right.

It's the right hand side, as I'm sitting on the bike, closest to the seat. Or right rear. Now, here is the odd part, I had thought for the longest time this might be a fuel mixture setting issue, when I give full throttle it will usually fire consistenly. And when I choke the bike it seems to help it, but of course just for a little while, and choking it causes the high idle, etc. I'm confused why choking the bike would help, if it's not a mixture issue....

Thoughts? Suggestions?

Joe

 

[06VMAXIMUS]

Pilot jet most likely plugged. I would probably start with the easy stuff by making sure you are getting spark at the plug, then drain the carb bowls and look for junk in them. Check the fuel tank and filter for rust, but at the end of everything you will probably have to pull carbs and disassemble/clean them. Also take a look at your intake rubbers for cracks-air leaks.

 

[Traumahawk]

Yep, probably a pilot jet issue. That circuit will provide fuel at part throttle (usually 1/8-1/4 of throttle, and usually from 0-4000 rpm.)

So do this....http://vmax.lvlhead.com/tips/shotgun.htm

I also usually take out PAJ#2, so that way i get a full blast of air into the carb.

Usually a pop is a lean condition. Its because the mixture in the cylinder is too lean to fire......but when it hits hot exhaust then it will fire.

To see it in action, look at the Isle of man/TT races.......those people when they back off the throttle, they throw FLAMES out the exhaust.

 

[dannymax]

Yep, probably a pilot jet issue. That circuit will provide fuel at part throttle (usually 1/8-1/4 of throttle, and usually from 0-4000 rpm.)

So do this....http://vmax.lvlhead.com/tips/shotgun.htm

I also usually take out PAJ#2, so that way i get a full blast of air into the carb.

Usually a pop is a lean condition. Its because the mixture in the cylinder is too lean to fire......but when it hits hot exhaust then it will fire.

To see it in action, look at the Isle of man/TT races.......those people when they back off the throttle, they throw FLAMES out the exhaust.

Or ride behind Dannymax's S1000XR at night! :biglaugh: