450r cutting out on top end

[hauck400ex]

I have an 05 450r with the HRC kit installed and a full Curtis Sparks exhaust... the bike has run great for a long time, and at the tail end of a 4 hour ride it started cutting out on the top end... it has done that now again since i took it out for a spin... not sure what to start with, im assuming jetting, but maybe electrical? any tips would be great... thanks

[ghott]

Make sure everything electrical has a good connection.

Make sure you have no leaks where the exhaust head pipe bolts onto the head.

Make sure your Air Filter and Carb are clean.

Make sure your cam timing is correct, and the chain didn't jump a tooth.

Check your spark plug.

Make sure your valves are adjusted and shim'd within spec.

If the bike is cutting out on the top end, and the jetting is to blame, mess with your MAIN jet, and A/F mixture screw.

This is all I can think of right now...

[MR.BIG]

This may sound stupid but you are not hitting the rev limiter are you, which is making it cut out:blah:

[hauck400ex]

no its not the rev limiter... it ran great for so long, but it falls flat once i get higher in rpms and closer to WOT... im assuming its jetting, but would i have to go bigger or smaller in jets?

[MR.BIG]

Do A wide open throttle run and pull the spark plug. It should be a tan-golden brown color. If its black to rich and white is to lean.
Its getting colder out so it could be running lean!

[speedfreaksguy]

Check for something plugging your main jet. Cooler temps require fatter jetting but it shouldn't change that much in one day.

[xsr_racing28c]

I actually had the same problem with my 04, and it turned out to be that i had over oiled the filter and it just stumbled...

[John Pennella]

My machine was cutting out on top end to before and when i checked the spark plug, it was alittle loose which was enough to mess with the compression. I tightened and it solved the whole prob but my quad is stock so for u it could be something else.

[honda4life72]

i found out on mine the gas in the tank shifts to the bak and make sit cut out..that it is your on the verg of going on reserve