Go-Kart will run fine then run at half speed.

[landuse]

Yeah. Put a new plug in and report back

 

[OzFab]

Check your spark plug sounds like deposits may be cutting your spark. Wire brush it when engine is missing or you see smoke. Read your plug then as well, could explain why your engine does great for a while then decreases performance.

It could also be that the plug is dying &, as it heats up, it gets worse (it does happen)...

 

[SpeedDemon1990]

Thanks guys. I'll look into it. Btw, my chain guard has busted for the second time and I was wondering if I really need it. I'm kind of worried about the chain snapping and smacking whoever is driving it, worst case scenario. The chain is brand new, tho. Any thoughts would be appreciated, as always.

 

[landuse]

A chain guard is always a good safety precaution

 

[Sebastian]

I had a problem with that once and it turned out to be a combination of bad gas, rusty carborator bowl, and bad spark plug. I bought one of those fancy spark plugs with the horseshoe shaped end. I think that helped more than anything.