I just installed a tri-power setup from a 1968 Corvette on my 427 cid 390 hp big block. It idles great and the power when I kick it is amazing. The only issue I am having is that at a steady speed there seems to be a little surging periodically. It seems to settle out but each time I give it a little more gas it will surge some more then settle out only to repeat this pattern each time I give it gas. Has anyone out there had this problem and tell me how to solve it?
Thanks,
RSAIII

 

This may be linkage adjustment or even some looseness in the linkage.
It needs to be "firm", not sloppy.

BTW, too tight of return springs promote linkage wear.
Use your strongest returns on the pedal linkage.

 

As I recall the Tri Power had a vacuum operated progressive linkage for the front and rear carburetors. Check to make sure the front and rear carburetors throttle butterflies are completely closed. Might check your timing also to make sure its not too advanced.

 

Vacuum?
Figures, check for leaks and still check any mechanical.
As I understand, a surge can come from fuel or air issues.

I prefer mech linkage.
People say "it's too hard to balance".
Not if ya know what cher doin'
and take your time.

 

I agree that mechanical linkage is good for race cars however I prefer vacuum operated secondaries for better street driveability.

 

Thanks,
Tightened linkage, reset accelerator pump gap and used stronger spring....surge is gone, run like a champ. I'm all smiles now.
RSAIII

 

Congrats!
Thanks for lettin' us know.

 

+1

Always nice to hear back on solutions and might help someone in the future.