Hi all.



I've just striped down a motor that was having oil problems (the oil pump was cracked and it had next to no oil presure) apart from the front Stationary gears Bearing is goosed the front Rotor bearing seems to have moved out of place?



When i had a look at the Rotor the Bearing had moved so far out of place it had been touching on the Stationary gear, it does'nt apear to have been Turning in the Rotor infact it looks in good condition apart from not being correctly placed.



I was woundering if it may have had a Rebuild in its life and they have not been replaced properly? or is it possable the rotor got so hot that it became loose???

Or maybe at one time the motor spun a bearing, and then someone figured it was ok to just slap a new one in. Could have just been installed improperly, who is to know?

Ive heard a number of times about rotor bearings "walking" at high rpm. Racing Beat, as well as at least one other company(i dont remember their name though) offers a service to mechanically lock the rotor bearing in the rotor.



That being said, this is the first time I have personally seen or heard from someone whom this actually happened to.

if its been rebuilt then perhaps the bearing doesnt have the proper crush in the rotor anymore?

Does anyone have the size the Rotor should be so i can make sure its not oversized before i fit the new bearings?



It has defo not spun (its just about on the edge of the key), This motor is fairly stock so i can't imagen it would have been submited to high rpm for long periods?

my advice would be to either ditch that rotor, or whenever you sort out your bearing issues, get the gears on both rotors locked.

I pulled apart a 6port N/A race motor last year that was over-reved. Both rotor bearings had 'walked' out of the rotor toward the stationary gear, the one was fused to the e-shaft. Both rotors had hit the irons and deeply gouged the iron and hammered the rotors.



It was a mess, nothing inside the motor was useable execpt the rotor housings LOL.

Yep i have just pulled it to bits and the Bearing has spun (its Sheared the Tab off the Bearing)



I realy need to get the Bearing out and Measure the Rotor (just to see if the bearing carrier is oversized) Does anyone know what size it should be?

Can you reuse a rotor that has had a spun bearing?

Nope bin food, its also killed the rear Bearing and both Main bearings (possably the crank) and one of the Rotors.



Shows you don't get much time when you have no oil going round, i'm guessing if it was a Piston engine there would have been alot less Damage as the Crank would have thrown some oil about in the Bottom end.



O well you live and learn.