After many years of running the CV carbs on my 150, I decided to go with a Mikuni VM-32. Never messing with a slide carb except for the ones used on the 50-110 buggies I had a new learning curve. To tune a CV carb, a main and pilot jet is the extent for tunning. The Mikuni as well the main jet and the pilot but also the needle jet, jet needle, throttle valve, main air jet, , needle valve and slide all play a part in tunning. The carb I chose was not setup at all for my 150 and I almost pulled my hair out getting the engine to first idle then run without the backfire then the fine tunning. I was fortunate enough to have the guy from Carb Parts Warehouse which is the main distributor for Mikuni in the US, help me to tune it to a baseline so that main jet and needle was all I needed to mess with to fine tune it. Man what a difference as compared to the CV carb. Now when I hit the gas there is no more lag but instant go. With the 32mm CV carb when I nailed it in the grass the tires would spin for a few feet then hook up but with the Mikuni when I nail it I now leave 2( 30' tracks before the tires hook up with lots of fishtail. It takes a lot more time to get a baseline then final tune but it is well worth it for the performance you gain. It will really wake a performance engine. I guess thats why all the sport atv and dirt bikes use them. Sounds like your close to dialing it in. The only thing I wonder is if the fuel will eventually eat away at your vacume tubing. Many plastics won't hold up to fuel especially if ethanol is in the fuel you use.
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