high revs after warm up

Need a little direction here...

1982 XJ550J. First time out today for more than a short run down the street. Put about 6 miles on it.

The problem: Once it's warm, it runs at about 4K rpm. If I push down on the adjustment screw between carbs 3 & 4 it'll come down to "normal" (1100rpm +/-).

Observations: All return springs appear to be in place and have tension on them. good slack in the throttle cable. On all three adjustment screws the two springs for each are present and accounted for.

Suspicion: The throttle return spring on #3 & #4 aren't wound tight enough and therefore do not have enough tension to hold the plates closed.

I think I need to pull the carbs off the bike to correct this, so I'm hoping before I do that someone here can either confirm this is the right thing, or suggest something else I might have overlooked.

Thanks!
Doug

 

after you have set it back down to 1100. Does it do it again and rev higher again after more riding?

 

As soon as I take pressure off the adjusting screw it goes right back up. No riding required.

 

Doug I had a similar problem and it was one of my springs misplaced so it was not wound tight enough.

I could also be a sync issue - but check your springs - worked well for me....

 

Springs "look" properly wound, but definitely not enough tension.

I took a short cut - but a $2 spring from the hardware store. It's a bandaid approach, but will work for now. Once the season is done I'll break them down and see whats happening.

Thanks guys!

 

Did the new spring help?

 

New spring did the trick! Put 30 miles on it since adding the spring, and it's running great!

 

Cool well at least you know how to fix her up