Would incorrect vacum sync make 2 cylinders run cold

[odl777]

Would too much sync on the outside carbs and not enough in the 2 and 3 cylindersa make the 2 and 3 cylinders run cold. Is there such thing as too much vacum. thanks.

 

[odl777]

anyone, keith maybe? thanks

 

[Billy Ricks]

If they are firing at all they should heat up. Have you ever determined if you're getting spark on 2 & 3?

 

[odl777]

no just trying to get as many questions answered before i go home for the weekend. Because when i am working on her no time for the pc. I'll let you guys know what has happened.
I was just wondering if my sync job could of done the bike wrong. thanks for the reply billy

 

[DimitriT]

Yea, if your throttle adjustment is shutting down 2 and 3 on idle, they'll be cold.

 

[odl777]

how would my idle be shutting down? explain please. thanks

 

[duaneage]

If the throttle plates on those two carbs are closed all the way then no air would make it through the carbs to pull gas

 

[Billy Ricks]

no just trying to get as many questions answered before i go home for the weekend. Because when i am working on her no time for the pc. I'll let you guys know what has happened.
I was just wondering if my sync job could of done the bike wrong. thanks for the reply billy

If your carbs were all pulling the same vacuum when you synched then this shouldn't be the cause. I still think you have an ignition problem being that 2 & 3 are the problem cylinders.

 

[odl777]

i thought cylinders 2 and 3 dont have as much vacume as 1 and 4. mine are barley off from one another

 

[Billy Ricks]

i thought cylinders 2 and 3 dont have as much vacume as 1 and 4. mine are barley off from one another

With srock pipes and airbox the two inner cylinders are supposed to be set slightly lower.

 

[odl777]

I have different jets and staright four in to one exaust, pods. so now i should change them to all the same sync. I sure hope the porblem with 2 and 3 is a loose plug in. thanks again

 

[Billy Ricks]

I have different jets and staright four in to one exaust, pods. so now i should change them to all the same sync. I sure hope the porblem with 2 and 3 is a loose plug in. thanks again

The reason for the different setting on 2 & 3 had to do with the crossover of the stock exhaust.

 

[odl777]

Makes sense to me now. I really never thought of that. Reading all the posts and things makes me excited to get my bike to its normal self. thanks for all the help so far.

 

[nabrams]

Have you actually measured compression on all cylinders and compared?
If 1 & 4 have significantly more compression than 2 & 3, then 2 &3 would not get as hot.
Low compression is often due to not enough valve clearance.

 

[odl777]

Would that caus ethe bike to run on two cylinders you think? I have recently rebuilt the motor with new rings and such maybe i'll look into that more if i cant find a electrical problem. thanks