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73 mt 250 gas leak https://vintagedirtbikeforums.alp-sys.com/viewtopic.php?f=21&t=3095	Page 1 of 1

Author:	nosfoursale [ Tue Sep 20, 2011 7:34 pm ]
Post subject:	73 mt 250 gas leak
I purchased a 74 mt 250. It keeps dripping gas out of the carb overflow tube after I take it for a ride. The dripping eventually stops after a couple of hours but it makes a mess and stinks up the garage. I rebuilt the carb with new seals and jets with the thought maybe the float was sticking. Before the rebuild it would have a steady stream of gas out the overflow, now it is just a drip ... Any advice?

Author:	rayivers [ Tue Sep 20, 2011 8:24 pm ]
Post subject:	Re: 73 mt 250 gas leak
This seems to be a common MT250 problem. The same carb is leak-free when using premix (I have a theory about this... ) but at any rate... did you try replacing the float needle and needle seat, then setting the float height to 20mm? Here's a good rebuild kit - it's got a bunch of stuff many kits lack: http://cgi.ebay.com/ebaymotors/HONDA-MT ... 336bb4e7ec Here's a link to the service manual - the float height setting procedure is on page 61: http://alp-sys.com/honda-elsinore/manua ... 5mt250.pdf Ray

Author:	nosfoursale [ Tue Sep 20, 2011 8:48 pm ]
Post subject:	Re: 73 mt 250 gas leak
Thanks for the advice. I actually used the Keyster carb kit. I changed everything except the Jet needle. I even have the official shop manuel from Honda and I followed the manual very closely. Could not changing the jet needle cause this. What would a old needle cause? I was pretty sure about the float hight... Thanks again.

Author:	rayivers [ Wed Sep 21, 2011 5:44 am ]
Post subject:	Re: 73 mt 250 gas leak
Changing out the needle won't affect the drip, but you might want to try it just to see if makes the bike run better, especially at 1/4 to 3/4 throttle. It's possible that fuel contamination could be causing the float needle not to seal properly. An inline fuel filter would be easy to install, and a good idea in general. It's also possible the needle seat is not sealing 100% to the carb body or that the body has a crack in it, but these are unlikely. Ray

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