High revs after warm up

[cbsavage]

My bike is a 1979 cb750k with 31,000 mi. It was Givin to me after it sat outside in a field since 2002 with the carbs off and intakes plugged with plastic bags. Got it home and put Marvel mystery oil in the cylinders and let it sit for a week before hooking up a battery. With fingers crossed I hit the starter button and it turned over with no problem . The previous owner ordered carb kits for a1981 cb750 that was in miscellaneous parts. I was able to use some of the parts but not the float valves. With the help from a friend, cleaned and adjusted the carbs. Had to heat the carb boots to get the carb to set in with the help of a ratchet strap. Started it adjusted idle and took a ride. It ran good until it got up to temp. Then the revs went up to 3500 rpm. I downshifted and hit the brake. The revs came down but went back up to 3,000 plus rpm. I would like to know why this is happening. Any help will be appreciated.
Thanks for a great site. Richard

 

[tommycarl]

Stock air box and paper filter, or pods?

 

[cbsavage]

Stock air box and Honda filter. No pods (yet).

 

[amc49]

False air. Leaking air or carbs messed up or engine to make you have to set the idle speed screw too high. You absolutely must have an air supply from somewhere to idle too high as with a hang.

 

[cbsavage]

Thanks AMC49 for the advise. I'm going to get new carb insulators then work from there. The stock air box and new filter was the first thing I tried.

 

[cbsavage]

I got new Honda insulators, reclean cabs, checked float adjustment and all cables. Too a ride and three revs still run up to 3000 rpm after a few miles. I noticed on another set of carbs that there is a plastic "T" between carb 2. @ 3. On my set there is a small piece of clear hose that connects ts the two carbs with no vent tube. Could this be my Rev problem?

 

[amc49]

You absolutely need those vented there. Cut or slice the tube to make a small hole in it. Or make up another tee there.