Today I started the process of tearing into my engine to replace my cam chain tensioner shoes. Part of this process is to remove the tank. I had the bike sitting in the garage running at around 2K rpms to burn the last of the fuel. After about 15 minutes the transmission started burping oil out of the transmission vent. Has anyone ever heard of this happening? My trans has never done anything like this before.

 

The only thing I can think of that would cause fluid to come out of the vent is over servicing. Have you checked the fluid level?

 

I presume you had a fan on it when you ran it in the garage for 15 minutes at 2000 rpm?

 

Yep, I thought the burp was caused by overheating so I immediately shut it down.

 

Mine does it all the time if it's really hot and I let it idle too long while I get the shed opened. I just figure if it's spitn' it out it didn't need it..! '94 FXDWG

 

2000 rpm for 15 minutes that sucka must have been hot! I blued a V&H head pipe once trying to run my metric dry. That was just from the fuel remaining after shutting off the petcock.

Think big *** fans!

 

If the transmission lubricant gets over 212 degrees, accumulated moisture will cause it to foam as the water boils off. Might be what happened in your case, and it may not happen under normal riding conditions.

 

Thanks guys. While she is down for the tensioners I was going to change all the fluids and do all the annual maintenance.

 

, Laws of physics at work. Even with very little moisture the oil will expand with heat and overflow, especially with no fan in an enclosed space.