High idle speed

[Guaire]

After warmup my 84 vf500 Interceptor, sometimes wants to idle at up to 3k rpm. I'll let the clutch out with the front brake on to make it get lower, hit nuetral, then engage first for take off. Otherwise, it can idle at lower speeds. Could this come from cracked rubber on the carb insulators?

Thanks,
Bill

[loopsandlogic]

You want to make sure your carbs are perfectly sync'd.
This is the number one problem from High idling.

After that, you might want to check your pilot screws just incase they aren't perfectly set
properly.

Cheers,

LL

[VT Viffer]

Any air leaks will increase the idle speed. Your theory about cracked boots can be tested with a running bike and some of that junk that you spray down the throat of a 1974 Caddy carb to get the beast to start. I believe it's referred to as "starting fluid" - how daftly named...

Spray it lightly on the boots and see if the idle changes. if so, you have an air leak.

However, when I first read this post, my first thought was a stuck choke slider.

[Guaire]

Thanks, for the directions. I should be able to check the choke, just by looking for the puller on the carbs. I'll get some starting fluid to see if I get a speed increase.
I tried tuning my carbs. I connected my Motion Pro guage 1 to cyl 1, guage 2 to front cyl 2, guage 3 to rear cyl 3, and guage 4 to front cyl 4. It got chaotic trying to get cylinders 1 and 2 to get in line. A mechanic at Coleman PowerSports advised me to connect same side front/rear cylinders differently. one can go to 1, but cyl 3 should go to guage 2, cyl 2 to guage 3 and cyl 4 to guage 4. It's simpler in a drawing. I'll try this connection on Saturday.
I have tuned 'regular' inline 4s the usual way. Sync 1 and 2, then 3 and 4, then sync 2 and 3 to balance the pairs. For me the VF500 is a new and different setup.

Thanks,
Bill

[masonv45]

Carb 4 is "SET" and cannot be changed.

Sync the rest of the carbs (in firing order) to carb 4. Follow the manual.

If you can push in the brass choke valve on the carbs at all, then your choke valves aren't closing. Trying leaving a lot of slack in the cable.