[GooseMan]

Last night I performed a carb sync on my bike. My friend lent me his 4-guage carb sync tool, which seemed to work pretty well.

I hooked it all up to the vaccum lines, adjusted the screws and got all 4 carbs to be pretty even. 3/4 were WAY off, so I figured getting them all pretty even would be the solution the my extra buzzy motor.

Unfortunately, after a test ride, it seems the motor is a little MORE buzzy than before. The sync didnt seem to do anything...it might have made it slightly worse!

My question is if I have to re-install the airbox when performing the carb sync. I put the entire airbox back on, but noticed that its hard to tell if all the vaccum lines are hooked up correctly, since they are under the airbox.

Also, another thing I noticed is that when adjusting the RIGHT screw (between carbs 3/4), if I just *touched* it with the screwdriver, it would raise the RPM's. I'm not talking about turning, just touching it. Is that normal?

Thanks guys!

 

[rathershort]

No, You do not have to put the air box on while performing the carb sync. Leave it off.

To answer your other question... The screws are sensitive. how high is it raising the RPMS? You should hear a change in the motor as you adjust, but it shouldn't be revving up. Make sure that screw is not stripped... Normally when you screw it in it is adjusting the throttle plate that connecteds to both 3/4. If it is revving when you touch it, i wonder if that is because it is sliding through the hole and pushing on the plates. Does it do what it is supposed to do when you turn it with a screw driver?

I would make sure you connected all your vacuum lines correctly and just double check the synchronization of all the carbs. My carbs were way off and I had the same "buzzy" feeling you are describing. Once i synced them it was like night and day. How many miles on your motor?

 

[GooseMan]

I have about 12,000km on the motor (uhhh...7000 miles I think). I bought the bike used, and it had a K&N filter, DynoJet kit and full Hindle exhaust....no idea if the carbs were ever sync'd, so thats why I decided to do them. Changed the plugs too (put the plugs in before the carb sync).

Yeah, the screw does what its supposed to do, its just strange then when I touched the screw with the screw driver (not turning), the rpms would raise, just by a bit (from 1300 rpm at idle to a little less than 2000). When I turned the screw, obviously the rpm's would change, which is normal while adjusting, and then settle down to normal. So it seems to be working correctly.

It's just that the screw for carbs 1/2 worked normally. I'd put the screw driver there to adjust, and only when I turned the screw would you see a change.

I'll pull off the airbox again this week and re-sync. Gotta get rid of this buzziness!

 

[jbreit]

it is not uncommon for the idle mixture screws to be uneven on these bikes....which could cause uneven running as well.

give the throttle a very light bump here and there while adjusting, to make sure the butterflies aren't sticking.

 

[undertow]

i had a slight buzz and i found my bolts were loose on my front fender.
whens the last time you went around your body and made sure all the bolts and screw were tight

 

[tv321406]

where did you get the tool to sync the carbs? nowhere around me sells them or rents them

 

[undertow]

you can get them on indysuperbike.com pretty cheap