EC 300 problem!!!!!!!!
 

Hi all, I am back with my problem ec 300, I still have the flat spot on full throttle, both low end and mid range are great, but wont rev any more from there. I have now changed the main jet for 175 then 172, I have checked inside the timing cover, its all ok and dry and clean in there, the pug is fine, the pv is working smoothly and opens when it should, I have new carbon reeds, a repacked silencer, cleaned and re-oiled air filter, and a full engine rebuild, but still, still, still!!!!!!!!!!!!!!!!!! the bike wont rev. I have tried the N1ef needle in 1st 2nd and 3rd slots to.:mad:

What pipe do you have, and also you might want to go bigger on the main.

1 Float level is to low
2 fuel filter is clogged
3 Gas cap vent hose restricted
4 Carb vent hoses clogged

is it like your hitting a rev limiter? had the same problem just had to change the plug, the plug looked fine and the bike would start no problem just didnt rev. just change your plug for good precaution. most of the time its a simple solution b8eg

It could also be a powervalve problem where it is not opening up all the way.

Clerky Clerk,

Since this is a new thread and not a continuation of your previous one you're getting the same answers all over again.

I think it's time to borrow if possible either a different carb and/or ignition and CDI and coil unit. You seem to have exhausted all the other possibilities with your work. For some reason I just wonder about the "new carbon reeds" you mention but it's just a hunch.

You did not mention when this started happening. Can you back track and think was it after anything in particular you did or changed on the bike? I assume it ran correctly at some point?

I have a new plug in, I changed from norm to iridium with no difference, and yes it does seem like a rev limiter, I have a standard gg expansion pipe and standard gg silencer, the bike has always performed in this way ever since I have owned it, thats the main reason for replacing everything and rebuilding everything, I agree with needing to try another carb and cdi unit, but i dont know anybody else who owns en ec300. I went out today for a 4 hour run on some fast tracks, I tried reving in 4th to the bog out and then dropping down into 3rd to see if it would rev that way but no, it just bogged staight away. I thnk it may be time for specialist to step in, Dyno possibly

Hey CC,
My 07 ec 300 used to rev out to about 7-7.5k and then do the same thing.
I did not go into it much, just checked coil wiring-ok, fuel tap etc - all ok.
When I replaced the original muffler with an Fmf powercore 2 off of a 98 rm the motor instantly reved out to about 9-9.5.
More power everywhere....now very happy.
Cheers Mark

In your other post you claim that you adjusted the float height so it will lay on its side without spilling fuel. DUH!

If thats true that means your float height is way too low. Up that baby and it should be fine.