Sync issues

Hey everybody. Finished changing the throttle shaft seals finally and I am in the process of syncing the bike again. I did 3&4 and had them balanced, but when I do 1&2 the bike starts to rev like crazy and white smoke is blowing out the exhaust. I let off the idle adjustment screw and have it as far as it can go so the rpms go down. Held a propane torch to all parts I can get to with no increase in RPM's, so no vacuum leak. This wasn't that hard a process last time, so what am I doing wrong?

 

Sounds like your butterfly's are not set correctly for the high idle issue, you may need to remove the carbs again and get you base set adjusted, not sure about the smoke coming out of the exhaust.

 

I bench sync’d mine using a business card I ripped to strips then on the bike adjusted the jet as needed.

 

Taking the carbs out again tonight. The throttle seemed a bit stiff when the bike was running good, so I didn't wind one as tight as before. Going to put that one back to what it was and see what happens

 

I've seen this type of thread before and it usually boils down to the rack being assembled incorrectly when putting the bodies back into a gang of four. I can't recall exactly what the issue was but it had something to do with the original setting of the sync screws and how the two halves (carb 1 and 2, carb 3 and 4) went together. Hogfiddles did a nice write up on how to do it but I can't find it for the life of me.

Side note, do you have the vac line for the petccock hooked up or blocked? That could create a nasty vac leak when adjusting.

Bench sync is good, but you should do a running sync on the bike for final adjustment. No bench sync can take into consideration variations between clyinders.

 

Side note answer, I have the vacuum line hooked up.

 

Hooked up to carb #3? Either way I’d test that main jet (the one with the metal plug over it closest to the engine). Albeit, if you didn’t use some gasket sealer/silicone grease or the seals haven’t settled that could cause problems too.

 

Yes to carb 3 when syncing 1&2. I used silicone on the seals so they would slide in without tearing.

 

White smoke is indicative of water being turned into steam. It's condensation and/or dust being burned off. That will decrease as the engine reaches operating temperature.

 

Pull the rack apart and redid carb 2. It must of helped, because it synced and is running just fine. Thanks for everyone's input. I'm sure I'll be back again, but hopefully not for a long time!

 

Sometimes all it takes is reseating.