TC250 fuel leak from case bottom when running

AnKhe105

Fired up the TC250 for the second time yesterday. The first time I did it a few days ago, had a runaway idle of about 5,000 RPM's. Got that settled down yesterday and was running well BUT....now I notice a raw fuel leak when running in the case bottom nowhere near a bolt or gasket. I'm guessing cracked case?? Motor is now out of the bike again. Can it be repaired? What's the best way of locating the crack? Can't really see anything much on the outside so it may not be visible when I get it apart.

I now have it apart and have the bottom case outside with gas in it to see if it leaks. Doesn't seem to maybe because it has to be under pressure and running?? I see a faint hairline crack on the inside under where the right side of the crank sits. That's the area it was leaking from yesterday.
Any help appreciated. Thanks, Doug

Could fuel leak out the bottom somehow if the center seals were bad?

dorT500 · Posted: Fri Feb 26, 2010 12:42 pm Post subject:

Just taking a shot here......as you know, this is a pic of your motor you posted in the past. I am not sure on your motor...but is that hole indicated not just a drain (with a matching hole in the uppercase) to let anything that collected on top of the case drain to the bottom and then to the ground? Carbs overflowing, leaking? Is this gas you are seeing relatively clean? Did you seal around that hole completely on the last assembly? Where exaxtly does the gas look like it is coming from? I am about to go to work in a little while (night shifts are getting old) Rolling Eyes

and will give it some more thought. Here is hoping that someone else may have some more difinitive input. Good luck.

AnKhe105 · Posted: Fri Feb 26, 2010 1:08 pm Post subject:

The hole you indicate is a bolt hole coming up from the bottom. The hole to it's left is the drain hole that runs through from the top. I had it running well last fall and didn't notice this leakage so I'm quite sure it was sealed but could be wrong. Fuel appears clean and drips off one of the bottom case fins away from any bolt below the right cylinder crank well. Hope this helps. Thanks dor

Checked the carbs when running and neither was leaking.

ol55 · Commuter Joined: Feb 09, 2009 Posts: 391 Location: VA

Looks like Zyglo dye penetrant can be used to locate cracks in aluminum. Magnafluxing can not be used.

http://www.skygeek.com/ats-za70.html

Larry

AnKhe105 · Posted: Sat Feb 27, 2010 8:03 am Post subject:

Holy cow Larry!!!! $630!!

AnKhe105 · Posted: Sat Feb 27, 2010 11:19 am Post subject:

Upon close inspection today, I now believe it was indeed coming from the carb overflow and through the drain hole on top. Don't think it's a crack anymore.
Thanks all, Doug

ol55 · Commuter Joined: Feb 09, 2009 Posts: 391 Location: VA

Does that mean you are not going to buy the kit? Shocked

Larry

AnKhe105 · Posted: Sat Feb 27, 2010 1:45 pm Post subject:

Wel....NNNNNOOOOO! Shocked