Wot under load kills motor?

[Frankenstein]

So helping a friend with the typical China girl, ported, windowed, reed, now it's getting hot enough on the crank case the paint is boiling off. Sounds like bearing failure? Also notice a bit more of a scratchy sort of sound that I don't normally hear.

Hitting wot while under load even when easing into it it has a tendency to cut out. Keeping the clutch in you can wot Rev it pretty well but too quickly seems to kill the motor, like the air just doesn't get pulled in fast enough and the motor stops from lack of fuel. If you keep the rpm low the motor can pull a bit but still pretty weak.

Plug looks really wet too. Sometimes starts with choke and also other times won't start no matter what.

Will a crummy bearing make all this happen so suckishly?

 

[Frankenstein]

And no leaks, that was tirelessly searched for enough times to know it just isn't.

 

[crassius]

one might think the reed has failed, but it would spit thru carb if so (unless the fail was holding closed rather than holding open, but that usually won't start)

 

[gary55]

what's the compression?

 

[Frankenstein]

what's the compression?

About 125...

 

[gary55]

That's a weird one. I've seen them get pretty hot with a seal leak, but never seen the paint on the case burn off. Probably cause they run crappy and erratic enough to force you to shut it down and find it. You said no leaks though.

 

[Frankenstein]

That's a weird one. I've seen them get pretty hot with a seal leak, but never seen the paint on the case burn off. Probably cause they run crappy and erratic enough to force you to shut it down and find it. You said no leaks though.

Exactly, was a powerful motor, had it opened and put together and it just is lacking top end power, lower is enough to give a good yank..

Odd thing, had the filter off and choking by hand with a small opening between the fingers got the idle to pick up speed... Also kept it alive while revving up, but that's not under load just sitting in front of the house dicking with it...

Already on the lowest possible jetting and this carb worked fantastic on a different bike, can't make heads or tails other than maybe the bearing is cooking along with the seal next to it, though the clutch cover is sealed well enough nothing is getting in or out (couldn't get a change with starting fluid being sprayed on the seal..)

If choking with my fingers makes it faster but choking with the actual built in choke doesn't help and even shuts it down then wtf is it?

 

[gary55]

I guess with that much heat you about have to take it down enough to see if there is any play at the big end of the rod or crank bearings, and what the wrist pin looks like.

 

[Frankenstein]

Well I should say very partial choke makes it run better but not much...

 

[Frankenstein]

I guess with that much heat you about have to take it down enough to see if there is any play at the big end of the rod or crank bearings, and what the wrist pin looks like.

But I guess the question I'm getting at is would a bearing in the process of dying make it run so odd?