revving to red line...... help

[opiwan]

So a while back I rebuilt the carbs and did a valve job and got everything running tip top. Then it ended up sitting for about 8 months as it needed a new clutch and I was starting a business. Finally got the clutch in and went for a shake down drive. I let it warm up and it idled well the whole time. Got it out on the road and it was running really well went about 3 miles, pulled over let it idle for five minutes or so and jumped back in and headed back towards the shop. About a mile down the road I let off the gas and notice that I'm not really slowing at all, hmmm this is odd. Push the clutch in to take it out of gear and the RPM goes through the roof! Shut the engine down and coast back into the shop and start looking at things. Mechanically speaking everything on the exterior of the carbs seems to be functioning normally. What do you all think? Stuck float? I've let it sit for a while and on trying to restart it goes straight through the roof. Thanks

[edzz]

A stuck float would not cause what you describe. It sounds like your carbs butterfly's aren't closing properly. First thing I'd check is to make sure the hand throttle isn't pulled out. Next pull off intake over carbs and verify that butterfly's are closing.

[GenevaPinz]

Had the same thing a few years ago and it was the hand throttle getting stuck. I would start the engine and it would jump to high rpms immediately.

[kdiqq]

Just pop the doghouse and see what your throttle is hung up on. Should be a simple enough fix. Unlike a diesel, a oil ingestion won't cause a clean, rapid increase in RPM. Whatever issue you're having is common across the two carbs, my bet is a throttle stuck.

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[Jim LaGuardia]

One possibility if you did not replace the old base gaskets, there is a tab on one of the throttle shaft washers that can contact the tin and stick almost wide open.

[opiwan]

Thanks for the responses! After some investigation it looks like I forgot to lock tite the pump rods. As I accelerated away from my stop they spun open and continued to hold the throttle open! Live and learn!

[kdiqq]

Glad it was an easy fix!

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