Wot under load kills motor?

[crassius]

certainly sounds like an air problem - maybe a crack somewhere in intake?

 

[gary55]

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?

Guess we were typing at the same time. Don't kill me but are you sure it's not the seal behind the rotor?

 

[gary55]

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

It would if it created a leak in the seal behind the rotor.

 

[Frankenstein]

Guess we were typing at the same time. Don't kill me but are you sure it's not the seal behind the rotor?

That's always possible, haven't taken it down there yet, there's a grinding noise I hear that I've heard only twice before, right before my main bearings seized...

 

[gary55]

That's always possible, haven't taken it down there yet, there's a grinding noise I hear that I've heard only twice before, right before my main bearings seized...

Happily I haven't experienced that yet. I would think either one could be the cause of the other. Most failures from to lean conditions I have seen trash the top end first.

 

[Deleted member 27811]

That's always possible, haven't taken it down there yet, there's a grinding noise I hear that I've heard only twice before, right before my main bearings seized...

I call it "Beef it UP-to break it Down. You guys make me jumpy to mod my engine much more, but watt the hell, beef it till it blows, they'll make more. right?

 

[Frankenstein]

Happily I haven't experienced that yet. I would think either one could be the cause of the other. Most failures from to lean conditions I have seen trash the top end first.

The cylinder and carb were moved over to a jackshafted bottom end that was still on the bike, the parts are compatable so it could be the failing cylinder before it had did the dirty to its bum bum...

 

[Frankenstein]

I call it "Beef it UP-to break it Down. You guys make me jumpy to mod my engine much more, but watt the hell, beef it till it blows, they'll make more. right?

Yerp, not an antique and cost less than a very bad paycheck to replace, burn that beef baby.

 

[Deleted member 27811]

Yerp, not an antique and cost less than a very bad paycheck to replace, burn that beef baby.

Make CHINA GREAT AGAIN I say....lol

 

[gary55]

The cylinder and carb were moved over to a jackshafted bottom end that was still on the bike, the parts are compatable so it could be the failing cylinder before it had did the dirty to its bum bum...

With 125 psi the cyl. sounds like it's still good. Putting the reeded cyl. on the other bottom end could have upped the case pressure enough to pooch the seal and turn up the burners. I guess I'm a bit stuck on the seal because of the heat and erratic behavior. The engine I just built kept pushing out the seal behind the rotor till I put a retainer plate over it. Now it's happy again.