Idles too high?

[jevaba]

Hello, new here. Have a couple issues with my first DIY kart project.

I have an old Murray frame that I put a HF predator 6.5 212cc engine on.

I originally had the engine bolted directly to the plate that's welded to the Murray frame, but I couldn't take the vibration. I bought some rubber pads and put them btwn the motor and the plate to absorb some of the shock. This moved my clutch slightly higher and back towards the drive sprocket (didn't want to redo my chain). Now when I start the engine, the kart tries to take off. The pads do seem to help a little with the vibration. What's the best way to address this issue? Do I need to move the engine forward and increase my chain length?

 

[Arrowking]

Did it try to take off before? If not, depending on how your throttle is setup you might have increased the tension on the cable which caused the throttle to be held partially open. If it did try to take off before, your idle adjustment could be set have been moved(probably not though because the purple screw takes some force to move).

 

[jevaba]

Thanks for the no reply. No, it didn't do it on any of my test runs before I added the rubber pads. I was thinking the same with the throttle, so I loosened it up, but it didn't help. I also loosened the nut holding down the throttle arm (governer arm?) because the throttle was a little sticky.

I can't really see how the adjustments I made caused what's happening. The sprockets are the same size and the chain is the same length, although it may be just slightly looser than I had it before.

 

[OzFab]

It's very possible that the clutch is now binding (drum is sitting on an angle different to the clutch pads) as a result of chain tension. I suggest you redo the chain (either lengthen or simply adjust if possible)

 

[landuse]

I am going to have to agree with Tony. You have now put too much tension on the clutch through having a chain that is too tight. You will have to lengthen the chain. You could add a half link or full link to lengthen it.

Google "half link"

 

[jevaba]

Thanks Tony and Paul, sounds like a very reasonable diagnosis. I will try lengthening the chain and see what happens.