I am VERY knowledgable about 2 stroke engine techknowledgy and the concepts and theories behind it. I ported out my blaster cylinder myself, witch consists of more stuff then i want to list and exlain now. It now has a LOT more power everywhere, and ESPECIALLY a lot more topend. Anyways, there is a set of whoops not to extreme, about 50 feet of them, Fast whoops. Before i had just enough power to get it into 4th before this set of whoops, Now i can easily power thru them in fifth, but with the stock front end and just a 400ex shock in the rear it is just too much for the suspension, Very rough ride, Very violent, But ive never had this problem, holdin it pinned in high rpms thru the whoops, after about halfway thru the whoops it looses power and starts to cut out like the plastic splash guard in the float bowl isnt there, but it is, its like its loosing fuel. im not sure what it is, its never done this before the porting, but there is no way the porting does it, it will not happen on flat ground or even going just 10mph slower through the same whoops. I only had about 1/4 tank of fuel, is it possible that just fuel is splashing around in the tank and the float bowl is running dry? not letting any fuel out the petcock?
This has seriously stumped me, has this happened to anyone else? or somtin simialar?

 

try it again with a full-3/4 full tank and let us know if anything changes... usually though, with my experience, extremely bumpy places with wide open throttle and a low tank of fuel = problems with the air fuel mix... hope this helps ya...

 

It could be a jetting problem. When you port your cylinder it is also good polish and mill your head to raise the compression. the more you take off the more snap it will have. Ask trinity or somebody how much you can take off before going into race gas

 

Thanks you guys, it just ended up that it was the low tank of fuel. Mustve just never noticed it before, or i was to tired to ride relaly fast by the time i had 1/4 tank, lol.

~jim~