High Idle / Self Revving Engine

Posted by Lowell on
URL: http://vintage-and-classic-hondas.81.s1.nabble.com/High-Idle-Self-Revving-Engine-tp4051110.html

Hi there. I've been using this forum with help to rebuild my 81' CB750c.
I've rebuild the carbs and have managed to get the bike started with no issues.

I've searched the forum but can't find my exact problem listed anywhere:

The bike starts up and the engine comes up to 3000rpm immediately. From there, on its own, it self revs up to 4000 and then back down to 3000. Repeat Repeat Repeat over the course of 10 seconds between.

Checklist:
High Idle screw is bottomed out.
Throttle cables aren't pulling when throttle closed
??

So essentially I'm trying to get rid of the combination high idle and self rev.

Any advice?