I have a Tao Tao 125CC quad that I finished putting together last Thursday. It has the forward neutral reverse gearbox and of course clutch driven. Until yesterday it saw minimal ride time. When you first start it up it rides like a champ but then the quad bogs down severely after about 10 minutes in the forward direction. If you shift into reverse it will resume power and go full throttle in reverse with no hesitation. Shifting back into forward it again bogs down almost like the brakes are locked up. The shipping oil was drained and replaced with the correct oil and again I changed the oil today. I"m now stumped as to what could cause this "bogging down" to the point of not pulling itself in the forward direction but resuming normal operation in the reverse gear.

Thanks,
Sean

 

Can it be shoved forwards by hand when in neutral? If it can't, the brakes could be the problem. Drum brakes have a leading and trailing shoe, and a broken spring or loose lining can jam the brakes "on" in one direction and not the other.

 

Yes it can be pushed while in neutral. It is only when the quad is "warmed up" that the issue happens. It runs fine in reverse but not forward when the engine/gearbox is hot. It seems to be gear or clutch related but I'm not familiar enough with the mechanics of this ATV to find the root cause. I could tear it down and look but its still under warranty only being a week old and I shouldn't have to do that.

 

Maybe it's getting "too" hot. Try richening your fuel screw. Also, you should have two different oils, one for engine and one for gear. Did you verify your gear oil levels?

 

Check the color of your plug. It could be running rich and with the gearing difference between forward and reverse when it loads up its easier to move in reverse