Son Scambler 90 is a slow need help

How do you adjust a automatic for more takeoff speed. There is only one screw on the carb. It ran good for a while then seem to slow down. We went thur some water.
I also used some yamaha injector oil to fill the oil injectortank. Could this have caused it to go slower.
All the reducers are off. What do I need to do to get him more power.

thanks

Sounds like you may have gotten the belt wet when you went through the water, but it should have dried by now. However, you could always pop the CVT cover off and check. If it isn't dry, give it a chance to.

I know that with a full-sized automatic transmission, a stiffer primary clutch spring will increase acceleration, but I don't know if anyone makes clutch springs for minis.

Also, the cold weather (depending upon where you live) may be affecting your son's mini. The cold air is more dense, which would cause it to run lean. Check the sparkplug to see if this is the cause. If that's it, a twist of the airscrew or a rejetting will remedy this.

well how many gears or speeds dose it have cause you might be running the engine out.

Quadkid, Scrambler90s don't have gears, they're belt-drive automatics.