ok i must say im a little ticked off... i went riding today first real ride since i put my hmf true duals on my quad.. i link up with some people from exriders.com and we meet and greet.. off we go to ride. everyone ohhing and ahhing over the powerfull V.. we doing the damn thing up the hills down the hills twisting and turning. and at the top of a hill suddenly the V just quits.. now im thinking to my self double checking yes i put fuel in it and sides the fuel light aint on.. i try to crank it over and nothing it dont even try. these guys are starting to look at me now brand new quad and its dead in the water.. so i hold it at WOT and crank again getting frustrated and it chokes and sputters to life running rough but running so we make our way back to the vehicles... get out the tools and pull the front plug out just to see.. and low and behold its fouled.. now im backtracking in my head and just to double check call hmf to make sure i jetted according to them and yes they say jet at 145 front 148 rear no other mods necasary. so now i turn to you experts why is my v fouling plugs if its jetted according to the pipe manufacture.. in the end i cracked open the airbox propping it open a little with the retaining clips and proceeded to ride for the rest of the day and at the end i checked the plugs again and they are perfect tan.. please someone help me here as i cant ride all the time with the airbox propped open there has to be another jet combo or setting im missing... oh and when it quit we was id say about 45 minutes into the ride if that helps...

 

If you say thay you are running with the air box lid open i bit and your no longer fouling plugs that means that your bike is running too rich with the lid on because running with the lid open would mean that the bike is gonna run leaner thus requiering you to put bigger main jets.

 

If he doesnt want to ride with the air box lid propped open this means he needs a smaller main jet correct? If he props it open it leans out the bike, so if he wants to ride with it fully closed then he needs to put in a smaller main jet to lean it out. Correct?

 

Sounds to me like he needs to do a snorkle mod to get more air in the box. Either buy the snorkle or the napa hose. I am going to put a double snorkle on my prairie when I do my exhaust.

 

If you improve the flow of gases on one side of the engine....you need to improve the other end too, or you wont gain much. Either improve the breathing, like a kn filter, or airbox mods, or youll need to lean out the carb.

 

Do you have an adjustable jet needles ? If so you could raise the clips one groove, might help. But yes you would see more of a performance gain by leaving the 145/148 and using snorkle or napa hose.-- by your description of use (mid throttle) is why I suggest needles.(positions them lower in jets)