Dual Weber 44's help

I am having a problem and would like some help!
2160cc, type I, When engine gets hot, engine won't idle down. It will idle rev up to between 2,000 & 3,000 rpm. I have tried to put a pair of springs on the carbs and that seemed to work for a while but now that is working all the time. On occasion this problem has occurred on inital start-up. Any help would be appreciated.

Rhino1
2001 VS

Check throttle cable/linkage binding. I had a similar problem with a new 1915 engine. The problem broke down as follows.......(engine was installed in a Spyder.)

The bracket aligning the cable through the shroud was not properly adjusted...You need a straight shot...

The cable guide/tube through the tube was missing....Allows the cable to saw through the sheet metal...

The cable routing used was too tight in the turns and also allowed the cable to contact the header.....Excess cable drag and the UHMW cable linning melted.....

As a result the braided cable frayed at two points and started locking the throttle in the MAX SPEED position....Not fun when a hundred twenty miles from home on a Sunday in the boonies.....

A new cable, properly routed, aligned, and guarded through the shroud, allows the dual 44's to return to idle every time using a very light spring on each carb.....

Check your hex bar linkage, (if used) for play from end to end...It should just barley move with a cold engine...Clearance comes as engine heats.... Check vertical movement at each end...If anything over a blond hair is detected, think about a new bar.....

Hope this helps....

Leon C.

Leon has some great advice, also, as your engine heats up, it grows in size. When it grows in size, it can seriously alter the alignment of your hex bar.

Here's a link for some good info.
http://www.carburetorclinic.com

look in tech articles:

Greg

Bruce, you said "It will idle rev up to between 2,000 & 3,000 rpm"

Do the rpm's return then rev again or just stay at those levels?
If they cycle up and back on their own you may have a vacuum leak.

If you isolate the throttle cable from the linakge does this still happen?

Bruce ~

Recently purchased a set of 44IDF's.

As soon as the oil temp reached 200 degrees ~ the Idle would soar and maintain 2,000 RPM.

Problem was the Venturi and Butterfly ware coming into contact once the engine/carburator expended due the engine reaching operating temperature.

This problem was detected in one carburator. The butterfly had to be "repostioned" and once there was no contact the engine & operation at cold or normal operating temperature is superb.

How this was detected (after exhasuting the normal trouble shooting techniques) ; get engine to normal operating temp + or - 200 degrees, disconnect the throttle linkage and physically close the throttle linkages if the idle doesn't go back to 900-1,100 RPM; inspect the carburator that is realted to the higher idle. The same technician that miss drilled my Butterfly may have done yours as well.

Good Luck ~

Jack