Hi I'm new to the site and need some help with my sons Yamaha zinger quad 2 issues
It runs but smokes a lot

And

It will not move with a 35 lb kid on it the wheels spin when I lift the rear up but stops when I put it back do

Any ideas I would like to get it moving first then control the smoking issue

Thanks

 

One might fix the other.
I'm not a 4 stroke guy but I'll throw some things out.
Compression. Low may mean valves need adjusted or the piston is wore.
I'm unsure if a 4 stroke pipe could build up enough carbon to plug them off (like 2 strokes can).
Have you cleaned the carb?
My daughters first quad was a moto-4. Ran ok but the most gutless thing ever.

 

I do not know much about this thing it is a 2 stoke motor. It ran ok last fall but smoked started to slow down so put it away for the winter. Would not start this spring finally got it running new plug choke was stuck water in fuel cleaned out muffler
Now it starts fine but will not move with son on it other than down hill

 

OK, 2 stroke.
First thought is a plugged up exhaust.

 

First thing I looked at

 

clutches? If an auto clutch it may be stuck in high gear...