Bike starts at 6,000 rpm...WHY?

[Elimax]

Hi all:

I re-built my carbs to change the main jets from 160s to 155s.

After re-installation of the carbs, airbox, etc., the bike starts at 6,000 rpm. This is with the idle adjustment all the way off! Throttle cables are fine, and I verified that indeed, the throttle valves are closed.

Any of you have any idea what's going on here?

Thanks very much.

Elimax

 

[satariel666]

Check the choke linkage.

 

[Elimax]

Thanks, satariel.

What do you think is going on with the choke?

Elimax

 

[naughtyG]

It's more than likely that your sync screws are way out of whack - also if you split your carbs it's easy to get the linkages slightly wrong on reassembly.

 

[gamorg02]

make sure all the plungers are in. full choke could be causing that kind of rise in RPMs (altho never seen it that high)!

 

[spyder13]

probably sync but look down inside and make one of the slides is not stuck

 

[Elimax]

NaughtyG...you say one of the sync screws my be out of whack...what does that mean?

Also, you mention linkages...which linkages are you speaking of?

(Just wanna make sure I do this right!)

Thanks for your help, folks!

Elimax

 

[naughtyG]

NaughtyG...you say one of the sync screws my be out of whack...what does that mean?

There's one screw on the left (flat head between the carbs) and two on the right. They are the carburetors sync screws. All four carbs must have their throttles opening at the exact same time (in sync) for the motor to work smoothly.
The screw on the left balances cylinders 1 & 2 (rear left and font left). The rear screw on the right balances cylinders 3 & 4 (rear right and front right). The front screw on the right balances 1&2 to 3&4.
You will need vacuum gauges or a Carbtune sync tool to do this.

Also, you mention linkages...which linkages are you speaking of?

The linkages that link all four carb throttles, and get adjusted by the sync screws.