Took my Honda 400ex out last year Rode fine all weekend. On the last day i was jumping her over and over on the dunes then we decided to go for a long run about half way into our ride she started to sputter and backfire. So i checked the gas plently in the tank I thought maybe bad gas or plug. Strange thing is it died and i could not start it so after messing with it i turned the reserve on and it started right up. I got it back to camp and changed the spark plug and still the same thing it would run fine on reserve but not in the on position. I even got another gas tank also i cleaned the heck out of the carb. Well i have not done anything to it since that last trip put brand new gas in with the other tank i had started right up ran for a little while and died took the cover off and checked to make sure the carb wasn't leaking I did notice the (not sure what to call it) out take hose on the carb was kinked. (basicly to small hose that connect into one on the left side of the carb) So i fixed it and it ran great. So i thought problem solved. Took it out just to make sure lastnight and the same thing is happing it will run all day long in reserve but not in the on position??? Anyone run into this??? is this a gas tank issue??? Petcok issue maybe??? I am so frustrated trying to figure this out. The other tank i bought off Ebay used so i am curious if this is a know issue with the gas tank going bad any help would be great. Sorry for being long worded.

 

Sounds like it's just the petcock valve gone bad, or possibly the primary fuel line is clogged.

 

yeah i was thinking to myself two tanks having the same issue? then realized i did buy it off ebay. used!!!! so it could have the same issue as my old tank cloged primary line inside the petcok Humm guess i will drain the gas and blow it out tonight when i get home. Thanks for the suggestion.

 

No problem, and welcome to the forums.

 

Do you have a normal vent tube on top the gas cap? Or do you have one of those little aluminium trinkets? Those little fancy deals don't vent very well, I have found.

 

mine does the same thing from time to time it's in the petcock main tube blow it out with an air compressor and it will be fine for six months to a year.or at least thats how long mine runs fine before needing another blow job!Show it some love man and she will straighten right out for ya![img]i/expressions/face-icon-small-wink.gif[/img]