Vibration

[Jackham]

My buddy has a predator 212 Coleman minibike and we can’t seem to fix the huge vibration problem. It’s on a torque converter and we know it’s coming from the engine. The crankshaft spins straight and doesn’t seem broken but I don’t know what else could be causing the problem. Thx

 

[Minimichael]

I've heard about this on here before. There was a lot of good discussion in the thread. I think the final consensus was that this happens to predators every now and then.

 

[Jackham]

I've heard about this on here before. There was a lot of good discussion in the thread. I think the final consensus was that this happens to predators every now and then.

Is there anything to fix it or just go ahead and buy a new pred. All that’s done is valve springs exhaust and carb. Still has governor though. We’ve tried rubber washers on the engine bolts but still almost too much vibration to even ride

 

[creia]

All of the Predator engines vibrate to some degree- some MUCH more than others. What you SHOULD have done is test it out BEFORE you made those modifications, then you could have taken it back and exchanged it for another one. Years ago we had to do this with one of the ones we purchased.
Michael

 

[Minimichael]

Makes you wonder if the crank is the culprit. Unbalanced.

https://oldminibikes.com/forum/inde...doodlebug-shakes-real-bad.177561/post-1303508

 

[sparkwizard]

The real question is DID IT VIBRATE BEFORE YOU TOOK IT APART? Do you have all of the original parts? Can you unmodify what was done to the stock Predator? Can you do that, run the engine to break it in and then report back here?

 

[Jackham]

The real question is DID IT VIBRATE BEFORE YOU TOOK IT APART? Do you have all of the original parts? Can you unmodify what was done to the stock Predator? Can you do that, run the engine to break it in and then report back here?

No we got it off of marketplace and it vibrated at first but over time it’s gotten worse. We went today and got a new pred just cause we also had a broken bolt now in the crank

 

[sparkwizard]

Great! I am interested to hear if you can find anything loose or broken in the old engine.
I do not advocate for deception or deceit, but will the greasy one fit in the new box?

 

[Bird Brain]

Could be the crank. When they are machined from raw forgings the centers have to be established in relationship to the outside diameter of the throws. This center distance is critical for dynamic balance in the final product. Could be somebody was a new employee to that process. I would try swap flywheels first before trashing the crank. Could be the key broach slot in relationship to the magnet might be a little off also. That would be easiest to try first. Shame its brand new and problematic for you. Well hope you get it figured out.