1983 Magna 750 rpm issue

[teebee]

Having a problem with my '83 750. Engine idles nicely, but when I open the throttle, engine speed stays high, and sometimes gains more RPM's, even though throttle snaps back to idle position. I have to shut the bike off to keep from gaining too much RPM. Does the same thing while driving, between gear shifts, though controllable with braking. Confirmed that carb linkage stop plate is returning back to home on idle speed screw when throttle is released. Can't figure it out. Any help? Thanks

[TLRam1]

Sounds like you could have a lean condition you need to locate, either rubber boots letting air in or pilot circuit is partially blocked.

[L J VFR]

Sounds like you could have a lean condition you need to locate, either rubber boots letting air in or pilot circuit is partially blocked.

+1   Agreed.   You can spray WD40 or something similar around the boots while the bike is running, and if idle suddenly increases, you have found your culprit.    Good luck!

[MagnaMan84]

Could also be the linkages to all the other carbs are sticky and not returning to home position.  Just because #1 carb is doesn't mean the other three are.