Need to Mellow WOT Power at high revs
 

All,

I would like to mellow the power at WOT and high revs on my '05 EC300 - is it best to lean or richen the main jet?

If you lean the mixture you risk damaging the piston and cylinder. On the other hand, if you richen it you might foul the spark plug more often.

If you want to mellow the WOT power, then i'd suggest pre-loading the spring on the power valve governor slightly. There are washers you can buy for this (i think they are 0.4mm thick).

You can richen the bike one size in the main jet and or try a different needle.

You can retard the ignition timing but that will make a difference across the rpm range.

You can go to the 2k3 ignition or add a fly wheel weight.

You can install the dual map ignition and run it on rain mode.

You can add the reed cage spacer. There are two sizes and they make a big difference in slowing the response of power delivery.

You can reduce compression by adding more base gaskets.

You can start the triple cheeseburger and milkshake diet.

D
Doesn't the 05 have the rain setting option on the cdi but you need to add the switch? Do a search.

No, definitely don't try to soften the power by making the fuel/air mixture bad....as mentioned previously a lean mixture could damage your engine.

Best way is to alter the way the power valve opens...

Closed power valve = Lower Exhaust Port = Increased bottom end/lower RPM power = Reduced high RPM power.

I'll nibble..

Use your right hand..

...or perhaps a throttle stop?

I'm sorry, I just don't see how you can have too much power at WOT and upper rpms. That is exactly where you should be making peak power.. If it's too much gear it taller and/or use less throttle.

Good answer

some how had a 300 reed valve and spacer on my 05 250 from new ,fitted one of a 98 as the 300 valve did not fit without the spacer made a big difference maybe the way to go iv still got the 300 setup

Yes I have the switch - need to remount on the radiator hose as I keep knocking it when riding and inspect the wiring as it's a bit mangled -

It would be fine if I were racing for shorter times but its coming out of corners revving up I need nearly all the power I'm getting I'll be WOT and as the revs build to 3/4-max (at a guess) there's a hit and the acceleration makes it difficult to hang on when you've been racing for 2 hours already also makes precise throttle control difficult i.e. I need would WOT but then as it takes off and I'm hanging on trying to stay forward I need to precisely take 1/8 throttle off? Very difficult I end up staying WOT and hanging on but would be nicer to tame the top end a bit. (but only at higher rpm's ideally)