Hi everyone, I have a 2006 KFX 400 purchased new last year. The problem is when I run wide open for a length of time like a mile roughly I run out of gas and it dies, if I put fuel valve to prime it fires right back up. So I checked cap for venting, took fuel valve apart checked rubber diaphram, and replaced fuel line with a clear hose. You can see as I run higher engine rpms the fuel flow slows down, but speeds up and catches up as I slow down, you can see air bubbles appear the faster I go and disappear again as I slow down. Not sure what to do next.

PS . It seems worse when fuel tank is nearly full.

any suggestions would be appreciated

 

could be a clogged jet, dirt in the carb, i would start with a clean air filter and a thorough cleaning of your carb. If that dosent fix things I would then start looking for leaks, places that it could be sucking in air.... could be anything from a leaky gasket to inncorrectly installed air filter..

The tank being full and having a worse time sounds like a dirty carb clogged jet issue.... just my 2 cents

 

Odd that it happens with a full fuel tank. One would think that the extra weight of the fuel would force more pressure in the line. If you are running a fuel filter, make sure it is not too restrictive even when new. I had this problem on my Polaris Sportsman 400.[img]i/expressions/face-icon-small-smile.gif[/img]

 

Well I know the air filter is clean and installed properly (for the poor stock set up) I also took a screw driver with me and checked the drain screw after it died, the bowl was neerly bone dry. I think its loosing vaccum at high rpms and allowing the rubber diaphram in the valve to close, I talked to the local Suzuki dealer and they said they have never seen one that didnt work properly. I have also switched caps with buddy and mine still died as he pulled away.