High idle (4-5k rpm) for a few seconds

[Drew85]

Morleys jet kit with k&n lid, full kerker exhaust.

What would cause the engine to rev to 4000-5000 rpm and stay there for a few seconds?

Im sure its not the throttle cable because it does it using the choke too. Carbs have been gone through and only bench synced for now. I did find a couple exhaust leaks.

 

[jfeagins]

Sync the carbs for real, and report back.

 

[genecarroll]

+1 on sync. I usually find if the idle screw is set to high the rpms hang. Try and back off it a little and check.

 

[dannymax]

Bench sync will get them close enough to start so you can perform a real sync.

 

[Drew85]

When I did get it to idle halfway decent only one carb was showing any movement on the sync tool. Seemed like it was missing and popping(through carb and exhaust) quite a bit.

 

[dannymax]

They're 'fighting' each other, as you get them closer in sync it'll smooth out.

You can start syncing with the choke on to get it running better then compensate as you lift the choke lever.

 

[tugla]

sticking slide/needle also.......after sync reach down motor not running push slide up by hand and see if they all return at same rate....

 

[Drew85]

Finally got a chance to get it running right, runs great just a little stumble off idle. Once in a while I cant get a cylinder or 2 to register on the morgan carbtune, does it require cleaning or lubed?

 

[dannymax]

Finally got a chance to get it running right, runs great just a little stumble off idle. Once in a while I cant get a cylinder or 2 to register on the morgan carbtune, does it require cleaning or lubed?

Could be it needs cleaning, they do get dirty....use denatured alkie, no lube.