here is i picture from the back thank for the info but how do you get the gov off?do you have to take the motor apart?
There's three ways.
1. Take the engine apart, remove the internal plastic gov gear, remove and reuse springs - the best way, but most complicated, and most fabrication needed:
http://www.youtube.com/watch?v=FTNbDvfIHoo
2. Remove Gas Tank, and loosen the screw for the gov arm from the gov shaft that comes from the crankcase, spread the end a bit so it can pivot on the shaft without the shaft moving the arm, lube, and put back on with no screw, and reuse the smallest spring as a throttle return spring, and hook the spring to a bolt that holds the fan cover on. Put gas tank back on. That's how my 6.5HP is setup.
3. Remove Gas Tank, remove Gov arm and throttle assembly completely, and make custom throttle arm and mount and go directly to the carb butterfly, and reuse small spring for throttle return, put gas tank back on. - I did this on a 2.5HP engine
With no gov, you may have to give it a touch of throttle on start when choking, as the gov normally does that automatically. I adjusted the carb to be a bit rich to make starting easier.
*Also, the reason the trailer bucks, but not your Baja Bike, is because of gearing. If you have tall gears like your bike, you can go fast, but the engine doesn't make it to 3600RPM as quick, so the bucking either does not happen, or isn't near as noticeable. However, the low gear is better for doing legal 20mph speeds without clutch wear, and also has more takeoff torque, you just have to rev the engine high to be in the 40's.