RPM’s stuck at 2k?? (1 Viewer)

[85roktoy]

**See below… still having issue it’s driving me nuts!!**

New to me 77 with the 2F. PO said the carb had been rebuilt. Starts and idles fine but when it gets hot and I’m driving the RPM’s go up around 2k and hold there when I push the clutch in. I slow down coming to a stop and they come down to normal around 700 after about 10 seconds.

When I start again and RPM’s go above 2k they hold there even when I let off the gas. Any ideas where to start? It’s de smogged.

 

[B y r o n]

Try looking at your throttle cable/linkage for sticking.

 

[85roktoy]

I noticed today that it’s reving up on its own too so I don’t think it’s a linkage sticking. I’m definitely no expert on carbs so it’s a mystery still at this point.

 

[LandCrusher'70]

Possibly vacuum leak(s).

 

[spotcruiser]

Check the carb level when the RPMs are up. It sounds like the float is sticking or the valve is faulty.

 

[85roktoy]

Still trying to figure this out. Driving me nuts. It only revs up to 2k after I get over about 10mph and above. Once I start to slow down and speed comes below 10 the RPM’s drop down to normal. Speed is affecting it. May try to take a video tomorrow.

 

[85roktoy]

Anybody? All vac lines look good. The only way I can replicate the issue is to drive it. Will not happen if sitting still and idling. Once I get over 10mph RPM’s jump up to 2k and hold there the whole time through all gears until I slow down and get below 10mph.

 

[Skreddy]

Does a 77 have any emissions/ speed related vacuum equipment? If so, maybe it’s that. So something meant to lean out at cruise has a leak and is leaning too much or a vac leak. Just a thought.