Topic: cb450 revving like mad

[Carver]

alright so I just put new forged pistons (one extra point of compression) in the cb450 and started it for the first time today. The idle screw was set to around ~1000-1300 rpm and now I start it an it just immediately surges to 6k I didn't alter anything from the time I tore the engine down and the time it went back together except the pistons. Think its time for a carb cleaning or a rebuild? Should I change the jetting? are carbs the right track?

[fendersrule]

Make sure that your throttle cable is not in a bind and carb butterflies are properly closed.

It won't surge to 6,000 without throttle...

Follow Bill Lane's carb setup guide, maybe he will link it to you.

6,000 RPM right from the start is not a good idea with a CB450...it takes a little bit for the oil to get to the valve train.

[Carver]

yeah I coated the cams in oil with zinc additive for startup just in case.

 and obviously the 6000 rpm startup was not uhhh planned  im gunna check out the cables tomorrow to make sure they're not sticking

[fendersrule]

Yep. A quick look at the throttle levers will tell you the story.