leaking front bearing - last ditch fix
01-24-2011, 03:00 PM
#1
leaking front bearing - last ditch fix
I noticed that there a lot of threads concerning this issue. So, after reading most of the posts, the number 1 fix seems to be replacing the bearing. Well, my brand new n21r (single seal nova bearing) started leaking oil at the bearing, after only 5 tanks of fuel. I had to have been slightly rich on the bottom although the only evidence was the oil residue coming off of the flywheel. My last ditch effort? Rubbing alcohol! Ive used it in leaking hydraulic jacks to swell the seals, why not try it on a $15 bearing. I propped the engine up with the crank pointing as straight up as possible, and applied a small amount (enough to cover the seal) onto the seal without flowing onto the inner race. After 30 to 45mins i checked it. I pressure tested it. It only leaked with a good amount of pressure. It was much better than before so I put it back on the chassis and ran it. After 4 more tanks of fuel, there is no sign of any leakage! Now I can finish break-in worry free! At least no worries about the seal! Hope this helps someone else!
Sean
Sean
01-24-2011, 04:05 PM
#2
I noticed that there a lot of threads concerning this issue. So, after reading most of the posts, the number 1 fix seems to be replacing the bearing. Well, my brand new n21r (single seal nova bearing) started leaking oil at the bearing, after only 5 tanks of fuel. I had to have been slightly rich on the bottom although the only evidence was the oil residue coming off of the flywheel. My last ditch effort? Rubbing alcohol! Ive used it in leaking hydraulic jacks to swell the seals, why not try it on a $15 bearing. I propped the engine up with the crank pointing as straight up as possible, and applied a small amount (enough to cover the seal) onto the seal without flowing onto the inner race. After 30 to 45mins i checked it. I pressure tested it. It only leaked with a good amount of pressure. It was much better than before so I put it back on the chassis and ran it. After 4 more tanks of fuel, there is no sign of any leakage! Now I can finish break-in worry free! At least no worries about the seal! Hope this helps someone else!
Sean
Sean
Tip:do not run in engine that rich
excess oil fills the crankcase, when crankcase is pressurized by rpm the excess oil is blown out the point of least resistance
01-24-2011, 07:14 PM
#4
I'd question that excess oil is the root cause of the leak. Oil has a lower viscosity than crankcase gases and is harder to work through a leaky seal. So in my book the oil is a benefit in your case.
01-24-2011, 07:43 PM
#5
I know what ya mean chunk, and it makes some sense, but it is the oil that causes the pressure to build inside the crank case. Take a known pressure and volume for instance. If you were to decrease the volume, your pressure would increase (given there is not a leak). Try squeezing an empty pop bottle. I am a motorcycle tech and we deal with it all the time. You gotta be careful as to how much oil is in there or you blow seals. Also these engines are at 200*+, even 90wt gear oil gets really thin at high temps.
Sean
Sean
01-24-2011, 10:58 PM
#7
I know what ya mean chunk, and it makes some sense, but it is the oil that causes the pressure to build inside the crank case. Take a known pressure and volume for instance. If you were to decrease the volume, your pressure would increase (given there is not a leak). Try squeezing an empty pop bottle. I am a motorcycle tech and we deal with it all the time. You gotta be careful as to how much oil is in there or you blow seals. Also these engines are at 200*+, even 90wt gear oil gets really thin at high temps.
Sean
Sean
i really do know at least one thing about micromotors
01-25-2011, 08:03 AM
#9
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