Hello I’m looking for any help or suggestions, thanks in advance. I have an 08 Kfx 450r with a wiseco high compression piston and stage 2 hot cams with fci no box, full dasa exhaust and a power commander 5. Was tuned on a dyno and I have replaced the fuel pump and injector. It will sit and idle just fine all day and rev up without cutting out but when I’m actually riding it will just bog and fall on its face. Won’t even pull the front tires off the ground. After cleaning the fuel tank and new fuel pump and injector it seemed to help for a bit so I took it to the sand dunes and had the same problem. Runs just fine driving at an idle basically through camp to the gate but then there’s nothing.

 

Did you fix it ?

 

Hey did you ever figure out what was wrong? I’m having the same trouble. Thank you.

 

First thing I would do is figure out how to get a fuel pressure gauge on it and watch the gauge as you try and ride it. At least eliminate that if that doesn't end up being the problem.

Could be pickup in the tank, crack in a line some where. Pinch, kink, dirt. Fuel pressure and flow is the first logical thing to eliminate.