200M wierd issue

[Mr.Jake]

ok, i can usually figure these machines out but this one has me stumped...

I have a 200m that will idle nicely all day long, but boggs when given throttle.
I rebuilt the carb with the same outcome.
Put on a carb from another machine with the same outcome.
New plug, gas, the whole bit.
When i adjust the carb mixture screw nothing really seems to happen, still boggs no matter what. I checked timing and valve clearances and all was good.
There didnt seem to be much exhaust coming out of the pipe and the engine got hot fast, so i removed the exhaust and the bike ran great, lots of power, good throttle response. So i cut off the muffler portion and didnt want to keep it loud so just attached a lawnmower screw in muffler deal to the end, bike bogged as it did before. I drilled the center of the muffler straight through 3/8", same bogging issure. Is the muffler just creating too much back pressure still or could it be another issue? I've got a buyer for the bike but want to make sure it runs well before i sell it.
Thanks, Jake

[dougspcs]

Check that the mechanical spark advance is working properly..

I just had a similar experience with my 185..

Pulled the CDI cover off and tapped it, ran great for about 5 minutes. Then started again..shot some lube at it and seems to have cured.

[Nubbinz]

Could be electrical as stated above. Have you cleaned or replaced your spark plug? It could be a weak coil too. Have you checked the actual exhaust pipe ? Its like a half inch in diameter, on a Honda car that would be clogged after one night at the drag strip. Its viable after 20 some years its clogged on yours. Also, have you tried throwing a coffee can on that beast ? I think a trike with a fart can would be awesome.