Gas gas ec300 not hitting powerband

[candybuddy]

Hi my gas gas ec 300 no longer hits powerband when it has warmed up, it still starts first kick and idles fine has full power when it is cold but as soon as it is warm it does not hit powerband. There is still lots of low end power but its like theres a rev limiter before the powerband. I've done a bit of research and people say it could be carb related.

Can anyone help would be much appreciated.

 

[n_green]

What year and model. If it used to hit powerband and no longer does and you haven't changed anything chances are your powervalve is stuck closed. Pull the pipe, remove the rhs powervalve cover, replace the pipe then start the bike and see if the powervalve flapper is moving when it should.

 

[candybuddy]

Hi its a 2011 ec300 enduro, powervalve moves fine not tested it with the bike on yet. Piston has a lot of side to side play with the barrel on but not sure of what the tolerances are. Also the reeds have a very small chip out of them but again not sure if that would cause it because its tiny i will upload a picture of the reeds later. There the possible issues ive managed to find so far.

 

[Phaeton]

Sounds like power valve not opening.

 

[candybuddy]

Would this cause it to not hit powerband only when its warm though?

 

[gassergrant]

try the simple things like the plug, check the connections on the wires I had one just pop out on the cdi it ran crap.
blocked carb as only revs out when cold (on choke), air leak on carb mounts gaskets .
the reeds having a chip in them is not good, my bike spat some of the reeds in the engine, I remember that would not rev out ether
just some ideas

I personally think if the power valve it stuck would it not be stuck full stop ???

 

[bergerhag]

Maybe the weather got a bit warmer and your main jet is too big?

 

[Jakobi]

Could be lots of things. Bad earth at the coil could be breaking down at higher rpm too.

You'll need to start checking things off the list!

 

[wence]

Water in the carb or fuel?

 

[bkwdc]

Put blocked carb vent lines on the list.

 

[rosco]

I would check the compression before I did anything else. You should be able to get it up to around 170lbs with the throttle wide open with about 5 or 6 kicks.