Hello! - EC Power delivery?

[justsam]

Hi Guys,
Briefly after 20 yrs of trials, then 3 yrs racing, I've decided to have ago at Enduro. I wanted a late bike but couldn't afford an orange one so I ended up with 2010 EC300. Rode it half a dozen times now, including 1 extreme enduro and I have to say I'm very much impressed! Other than the usual maintenance, it seems solid and hasn't missed a beat so far
This is my first 2 stroke like this as in with a power band, so I presumed its just how they are and there's not alot I can do about it. Basically the power seems to come in very fiercely. Like when I try to build the revs up, attacking a bank or steep hill, as soon as the power band comes in it either spins up or send me onto the moon! Looking at other posts on here, there seems to be some amount of adjustment with the power band mechanism to smooth out the power. I'm will to loose abit of top end to make it smoother if that's the case. Also my bike has the very pronounced rattle on tick over which I here can be caused by the PV?
Sorry to waffle on a bit but any tips would be very welcome
Sam

 

[Mud-Ectomy]

Hi Justsam, you have probably already tried this but I believe the 2010 comes with the two position mapping switch.

Have you tried switching from Sun to Rain?

I personally feel it calms down the hit on my 2011 Nambo.

Martin

 

[swazi_matt]

you can also look at putting in a nedj needle to make the power delivery more linear (but not ever going to get it like a trials bike)

 

[Caravan Monster]

Hello Sam, there's loads of ways to adjust the engine characteristics, but it'll take some work to get it dead-on for the individual rider's requirements. Adding an extra reed valve spacer (with jetting changes to suit) to the intake manifold will flatten out the low / mid a lot. Doing this would make the bike feel a lot flatter and a bit alien to riders with enduro / mx backgrounds, but might work for a trials rider. Another cheap and straight forward way would be to experiment with different profiles of twistgrip cam, so that the throttle doesn't get into the hard hitting power as quickly.

If the rattle is getting loud, it might be worth cleaning the soot and spooge off the powervalve (there's a how-to on the forum)

 

[Jakobi]

As above you have many tuning options available at relatively low costs.

Easiest is to start with the jetting. If its the stock setup its nowhere near what the bike can be. Swapping needles for different profiles has profound effects on the delivery of the power.

You also have igniton timing (manually at flywheel and by the cdi with switch)
Shims for the actual PV governor that can be added or reduced.
Port timing and compression ratios.
Reed spacers and engine volume.
Flywheel weights.
Throttle cams.
Sprockets and final drive ratios.

Basically its up to you to determine what you want from the bike and then chase it. Jetting wise going to a NEDx suzuki needle will lean off the bottom end and richen up the midrange which will in effect smooth the delivery. You'll still have the powervalve characeristics but it won't be as pronounced. From your description it sounds like you'd probably benefit from some increased compression and then timing the ports to favour the bottom end (piston above the exh port at bdc). Going to a 50 tooth rear sprocket while sounding counteractive actually allows you to attack more in second gear which is much smoother than having to knock back to 1st with the 48 tooth. It also brings the shift point down for 3rd 4th and 5th so the bike isn't on/off the pipe as often. Easier to just keep it as one or the other.

 

[justsam]

Thanks very much for the replies folks. Certainly much to think about.
Firstly I'll inspect/adjust the power valve. Due to the rattle it has and see if there's any free play to take up. I did read somewhere that if the PV is over adjusted, so it operates earlier, contrary to thinking it actually makes the power more progressive. Does this sound correct? As for the jetting, I did adjust/richen the float level. But other than it seems to run quite well. Plug chop is good, never spultters or 'pings' so at this stage I'll leave that side of things.

Also I read alot about flywheel weights. Does my bike already have the heaviest weight? (2010 EC300 Cross Country) I presume a heavier weight could improve its rideability...