Hey fellow members i thought i would chime in and tell everybody what i have done to my cart and what i have found to be beneficial. My findings are not an exact science because i did not do any tests before the changes, but are pretty much by the "seat of the pants" opinion and GPS facts. First thing is i bought my cart stock straight off the course and built it to a 6" lifted, 22" tire wheel combo, back seat installed, custom painted, plowman carts performance kit, equas tach, grant steering wheel, all sports short windshield and rocker panels, brush guard with lights, k&n filter with filtered crankcase, modded engine,---- fun mobile! Sorry i went on so long but i wanted you to get the picture of what i have installed on my machine
Like any other guy i wasnt happy with the stock performance, so i started my endeavor to build a better machine. I have pretty much built up every small engine toy i have ever owned, lastly being my 2006 Polaris Ranger 700XP. Anywho, for my first performance upgrade i talked with Don Plowman(very acknowledgeable Yamaha guy) and he recommended his performance kit which consist of the shaved secondary clutch with new spring, new main and pilot jet, and of course the performance exhaust. With this kit installed i gained good hill climbing ability and a top speed of 26 mph. Not bad, but not good enough. I could do the "big block" engine, but i really didn't want to get away from the true "Yamaha Experience". I wanted to stay with the stock engine as long as there was power to be gained from it. The engine was tore down, the head was sent to the machine shop for a .025 mill job and polished ports, the cam off to California for a torque grind, and the pick up coil adjusted to some kind of advance(not sure of the degree). A K&N filter and prefilter was added along with more hogging of the main jet. Tried to index the plug but the threads were not allowing it. With the Plowman's kit i noticed an increase in torque and some throttle gains throughout the rpm range due to increased exhaust flow, but no difference in top end. Now with the modded engine, there is a noticeable(seat of the pants) throttle response throughout the rpm range with a "pulling feeling" all the way to the top speed of 32 MPH!!!!(GPS) That is a 6 mph gain people. My equas tach for some reason is acting faulty, i didn't have it on before the mods but after the mods, so i cannot compare rpm readings. Still working on that issue. But as far as wanting to keep your original engine and stay yamaha, it can be done with noticeable gains. The total price for just the internal mods for me was 160.00. Just letting the people who want to stay original know. Thanks--If you want to see a picture of my cart look under the thread "Say hello to black magic".