What does the plastic cup with the funnel going to the pilot around the main jet actually do? With the stage 1 K & N jet kit is says to remove it. Now over ruff terrain and jumping it cuts out and acts like it is not getting fuel. I was wondering if removing the plastic cup caused this to happen. Any ideas? Other than that the kn filter and jet kit seems to really smooth things up alot on the bike giving it nice power.

 

I think it helps prevent the gas from oxygenating (bubbling up) when going over rough terrain and helps it from splashing around in the bowl which also helps prevent it from oxygenating in the bowl. That would explain why on rough terrain your quad is cutting out, it's sucking air instead of gas.

 

Thanks for the info. I was thinking that it affected the gas. I wonder why k&n said to remove it?

 

I have both the K&N air filter and jet kit. I've had no problem with the machine cutting out. I do rough trail riding and motocross. Once you put a K&N jet in the carb the plastic cup will not fit anyway. The outside diameter of the K&N jets are smaller than the stock Yamaha ones. The cup will not stay in place. Sounds to me like your float setting is too low. Get more fuel in the float bowl and you will not suck air.