The TSP Keihin Carb and High Compression Head work great on my 300cc XCW. Much better than the stock Mikuni. Power band is smooth and just keeps pulling, amazing. Raced 60 miles last week in the Nevada desert of which 10 miles was frozen ground, ice, snow. Kept it on 2 wheels on the ice and was able to pull hard on the dry dirt. Very strong and useable power. Will buy more products from SBM.