I decided to rescue a DT250B that I had purchased as a parts bike for my original unrestored bike. The parts bike ran well before I scavenged the ignition switch, coil, stator and flywheel. So I purchased replacements for those items and went to work on it. Being retired allows me to make pretty good progress spending weekdays in the garage. I am still waiting on a few parts before I fire it up. It does have spark and it has very good compression. I’m waiting on a new petcock and UNI air filter. I may have to replace one of the floats because it seems to occasionally get hung up on the guide post if you hold the bowl in your hands and roll it upside down. I’ll update this post once she’s up and running.

imgur.com/a/6R8Hxqg
 

I’m happy to report that the 2fitty fired up on the third kick. It leaks fuel from the bowl gasket which I tried to reuse even though it was hard and cracked….   

It’s just too soft and muddy to take it for a ride. But the herd has now grown to 16 vintage Yamahas and they ALL RUN. This is the only place I can say that where people will understand what it takes to keep that many 50+ year old 2-stroke bikes running.





 

Sounds good!  

You mentioned float bowl gasket was cracked...  obviously that's a problem if it's broken all the way through.  But the original gasket, even if rock hard, should seal just fine after it gets wet with gas again.  They are amazing like that.

Clutch lever seal is leaking.

Nope. Just checked. Those wet spots on driveway were from the leaking float bowl. New gasket is on its way.

That's a sweet front porch to sit out on and think about fixing gaskets on your very lovely 250. Nice!

Brand new Yamaha gasket installed and the bowl STILL LEAKS……
The bowl screws are pretty chewed up so maybe I’m not getting them tight enough. I have four socket head cap screws being delivered tomorrow which should be easier to snug up as needed.

It clearly seeps out of the joint between bowl and carb. The edges of the joint surface are badly dinged up by the previous owner who was tying to deal with the sticking float that I had mentioned earlier in this post. He had obviously been rapping the side to free up the float.

I believe I cured the sticky floating by inserting the tapered tip of a mechanical pencil into the brass tube that fits over the guide pin and gently flaring the edge. I believe it had a burr around the edge of the tube.

But if it is leaking around the joint of the bowl to the carb then the float valve must not be shutting of the fuel supply. Oddly enough there is no fuel coming out of the overflow……… Very frustrating.

Edit:
The carb has been cleaned multiple times in the ultrasonic cleaner and all passages have been probed and blown clear.

Edit #2:
I just searched “leaking float bowl” and wow do I have a bunch of things to try…