Well boys and girls.... I had a psycho moment.... I took the engine back apart and the FRICKING brand new front bearing is leaking pretty bad AGAIN, after running for all of 2 minutes....

So, I called my LHS and ordered an OS 18tz-tx... $160 out the door... I don't care if its the same power I have now, or even a touch less, as long as the OS tuning and reliability claims are correct....

What would cause the front bearing to go bad so often and so fast? It's leaking between the crank shaft and bearing.... It's like the crank is too thin??? It's definitely not worn out from 5 tanks... you wouldn't think!

Not sure whats going on with yours - something dimensionally may be out of whack??

Good luck with the OS, will be way diff than an rtr engine, I know mine was - 18TM though not the TZ. It behaved and is still pulling after a couple of gallons.

you could have put the engine in the freezer for a little bit to have a tight fit around your front bearing.. you shouldnt have been able to like slide it out

that's cool, until i take it back out of the freezer and then things go back the way they were.....

well you put the bearing in there and freeze around the bearing, but it might not work

but whatever you bought a new engine

I had an airleak on my 3.3 front bearing when I got my revo.I upgraded my motor to a picco .26I also have a ninja motor that I thought had an airleak it would run the right way for the first couple minutes but after it heated up it would have an eratic idle that you couldn;t tune away.The fuel line was just very slightly kinked.Just looking at it you wouldn;t think it was a problem but sure enough lenghthen the fuel line 10mm and presto no more problems.Alot of front bearing don't seal all the way and it is common.I have a $700 motor in my mrx that leaks afo after a couple days through the front bearing but it holds a tune just fine.An eratic idle could also be the tune.Like if you pull it full throttle and after you let it go it revs high is because the low speed is too rich compared to the highspeed.So it wouldn't hurt to try tuning the low speed and making sure that fuel line is free flowing.