Auto-clutch mini 50cc bogging when in gear... why?

Hey all!

I received a Suzuki TrailHopper 50, 1971. It's a lot like the old
Honda CT50/70 in that it's an auto clutch with 3 gears. Anyway, It
hadn't been started in years - prolly 15 - 20). I changed the fluids
and it started right up. Here's the problem:
Out of gear it will rev just fine but when I put it into gear and try
to ride it will bog in all gears to the point the motor will die.
It'll also start right back up! Put it in 1st, start going with a bit
of a bog, shift to 2nd and more bogging. Sometimes I can go blocks
and blocks with just a bit of a bog - other times I can't get to the
end of the street without so bad the engine will die!!

So what's the deal? If it was a clogged fuel line or carb wouldn't it
bog while out of gear too?

Any suggestions?

Scott

'97 kx 250
and now Trailhopper

Clogged exhaust? Remove the silencer and see if it rev's right up. You just
might find a rodents nest in the exhaust pipe.

Thanks for the reply Tom! I will check it although just off the top
of my head wouldn't that affect it while out of gear too? It revs
fine when out of gear...
Thanks again and I'll look into it!

Check if choke is working properly, it could be locked in the open
position... This problem sounds like carburetor problems, did you fully
disassembled and cleaned the carb really good? Under load, the engine
demand for fuel is higher than when it is in neutral.