ryskie22 Posted March 2, 2009 Report Posted March 2, 2009 need some help here, i just put together a 421 cheetta cub this weekend and into the bike, fired it off and noticed very shortly that the right pipe was smoking alot more than the left, gave it rev and holy shit i could paint the wall with trans fluid from the crankcase. i tore it all back down thinking maybe i had a defective seal? not so and it wasnt installed backwards either. checked the cases were the yamabond was and looked good, cant see any place that it could have leaked? everything is new except the cases. after some hair loss it hit me as i was staring at the crank, on the keyway on the wet side for the drive gear i thought maybe it leaked through there,so i put the gear on and slid the keyway in and the gear actually rocked on the crank a little with two different keys! so my queston is could it be leaking through the keyway from excessive play in it, my old hotrod 350 crank wasn't like that. the key went in farly hard. well im leaving my cases split for a while to see if anybody else has this problem or any other ideas becouse i have no more ideas of why. thanks for everybody who replies Quote
tony cub Posted March 2, 2009 Report Posted March 2, 2009 need some help here, i just put together a 421 cheetta cub this weekend and into the bike, fired it off and noticed very shortly that the right pipe was smoking alot more than the left, gave it rev and holy shit i could paint the wall with trans fluid from the crankcase. i tore it all back down thinking maybe i had a defective seal? not so and it wasnt installed backwards either. checked the cases were the yamabond was and looked good, cant see any place that it could have leaked? everything is new except the cases. after some hair loss it hit me as i was staring at the crank, on the keyway on the wet side for the drive gear i thought maybe it leaked through there,so i put the gear on and slid the keyway in and the gear actually rocked on the crank a little with two different keys! so my queston is could it be leaking through the keyway from excessive play in it, my old hotrod 350 crank wasn't like that. the key went in farly hard. well im leaving my cases split for a while to see if anybody else has this problem or any other ideas becouse i have no more ideas of why. thanks for everybody who replies thats where its coming from..have had that problem with my 12mill dm...put some of your yamabond on the key way and between both gears.. Quote
Onesickcrewcab Posted March 2, 2009 Report Posted March 2, 2009 It sure sounds like a crank seal to me. What I would suggest is performing a leak down test. That is where you plug the exhaust ports, plug the intake ports and pressurize the motor to 6PSI. It should hold 6PSI for 6 minutes with minor leakage. This can be done several ways. You can make your own leak down tester, or you can buy one from different places online. If it does leak you can spray soap and water around to see where the leak is coming from. If you need some suggestions on making a leak down tester let me know. Quote
tony cub Posted March 2, 2009 Report Posted March 2, 2009 It sure sounds like a crank seal to me. What I would suggest is performing a leak down test. That is where you plug the exhaust ports, plug the intake ports and pressurize the motor to 6PSI. It should hold 6PSI for 6 minutes with minor leakage. This can be done several ways. You can make your own leak down tester, or you can buy one from different places online. If it does leak you can spray soap and water around to see where the leak is coming from. If you need some suggestions on making a leak down tester let me know. i hope he used new seals..lol.. Quote
ryskie22 Posted March 2, 2009 Author Report Posted March 2, 2009 i hope he used new seals..lol.. yes i used new seals Quote
sheefreak Posted March 2, 2009 Report Posted March 2, 2009 Tonycub is on to your problem. This is more common on straight cut gear sets, but like mentioned try some yamabond. Should fix you right up. Quote
ryskie22 Posted March 4, 2009 Author Report Posted March 4, 2009 just want to say thanks to everyone who replied it ended up being that it was sucking the trans oil through the keyway, little yamabond and shes cured :biggrin: Quote
tony cub Posted March 4, 2009 Report Posted March 4, 2009 (edited) just want to say thanks to everyone who replied it ended up being that it was sucking the trans oil through the keyway, little yamabond and shes cured :biggrin: glad you got it fixed..it drove me insane the 1st time it happened to me.. :: Edited March 4, 2009 by tony cub Quote
ryskie22 Posted March 4, 2009 Author Report Posted March 4, 2009 glad you got it fixed..it drove me insane the 1st time it happened to me.. :: yes you are very right i was going insane myself until i calmed down with my freind wiskey and stared at the the two case halfs and then it hit me the dam keyway. hey my fix was a .o15 thick big block chevy valve spring shim with some yamabond on the gear side placed inbetween the crank gear and the water pump drive gear to cover up the keyway, also put some yamabond on the keyway, it seem to work really good with that shim inbetween like that. Quote
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