I was working on an ex today and those things SUCK maintnance wise could hardly get the carb bowls offor fit a wrench any were ne ways i have a prob and i think its the jetting it bogs at 1/2 thrott. i tried leanin out because exhuast was dark it had a 248 main looked a little clogged cleaned it and still doin the same any help would be great i m at sea level - 500ft THANKS