I stopped my Beta from leaking fuel by puting a fuel filter on it. It has only started that leading when on the kickstand a very few times since adding the fuel filter. When it does I turn off the gas and run it dry then turn the gas back on and no leak. I think that carb is is very sensitive to dirt getting in the float needle. Mine came with 27.5/145 jetting. Going to a 30 pilot made a huge difference in the way it runs. I live at 2,000ft and our club has property at 6,000ft. I think it runs great at both altitudes. Never even had the plug out of it. Best behaved 2T I have ever owned. Never considered dropping the main to 135. Would that be too lean at 2,000ft?
Yes, a 135 would be too lean at 2000ft. We are talking riding around 7000. You might get by with a 140, but it will be close depending on your bike and how you do the air filter.
Often at high altitude it helps to cut the head to increase compression to get cylinder pressure back up to about where it'd be at sea level.
I know you said you machined some weight off the flywheel - but did you ever check for the optional FWW under the clutch basket? Some of the 250's had these mounted in seemingly random years. May explain the super slow revs. I think they added an additional couple of lbs!
I can`t wait till I get to ride this Beta Dog! P.S. I have not heard of anyone taking that much weight off a modern bike, since they now use plastic in the crank itself!
