lowering the powerband

[jasonbc]

Been getting to grips with bike a bit more now and i'm finding the powerband is high, much higher than on the 200 & 300 motor, I need to lower it so i can keep the revs up and give me more power in the low-mid range. (the motor is very aggresive) I have bought a lower front sprocket which should help gear it down a bit.

Does anybody know anything about fitting a weight to the flywheel and if they do can anybody explain how doing so gives more low range power. Apparently all the new GAsgas range come with rather big weights on them which is why the 200 and 300 are easier to ride then the 250's

[AlanH]

Extra flywheel weight gives the motor more inertia so it's less likely to stall. It also is less free-revving with a heavier flywheel. It makes it more rideable in difficult conditions but it doesn't alter the power curve and doesn't give more low down power.

Making a 2-stroke less mental is not quite as easy as changing to a milder a cam on a 4-stroke. The 2T motor relies on combination of resonance and the porting for its characteristics. You're pretty much stuck with the porting so you're left with a change of front pipe and perhaps a set of Boyesen reeds to try to lift the low/midrange but this will be at the expense of top end power. A smaller carb can also help with getting more midrange at the expense of top end power.

You could try something like an FMF Gnarly front pipe (ebay item 120466168729 for example) or a similar pipe aimed at boosting low/midrange. That'll probably make the biggest difference but ultimately this may just be the nature of the bike and you'll get used to it.

[jasonbc]

Extra flywheel weight gives the motor more inertia so it's less likely to stall. It also is less free-revving with a heavier flywheel. It makes it more rideable in difficult conditions but it doesn't alter the power curve and doesn't give more low down power.

Making a 2-stroke less mental is not quite as easy as changing to a milder a cam on a 4-stroke. The 2T motor relies on combination of resonance and the porting for its characteristics. You're pretty much stuck with the porting so you're left with a change of front pipe and perhaps a set of Boyesen reeds to try to lift the low/midrange but this will be at the expense of top end power. A smaller carb can also help with getting more midrange at the expense of top end power.

You could try something like an FMF Gnarly front pipe (ebay item 120466168729 for example) or a similar pipe aimed at boosting low/midrange. That'll probably make the biggest difference but ultimately this may just be the nature of the bike and you'll get used to it.

It's already got a complete FMF power core 2 pipe front and rear, it is also running Boyson Reeds (pwr21's) i think according to the packaging. I have just put a 12t front sprocket on the bike instead of a 13T will try it in the morning to see what difference it makes

[AlanH]

It's already got a complete FMF power core 2 pipe front and rear, it is also running Boyson Reeds (pwr21's) i think according to the packaging. I have just put a 12t front sprocket on the bike instead of a 13T will try it in the morning to see what difference it makes

The 12T will make it a bit less likely to bog down at low rpm but the smaller sprocket may make the sudden "scalded cat" effect worse. Going from the XR to the Gas Gas is bound to require a bit of time to adjust as the power delivery is so different.

There are different FMF front pipes and some are tuned for peak power rather than low to midrange. Hopefully the pipe has its identity stamped onto it as the power core 2 only refers to the silencer. You may have one fitted that's more top-end focused.

[jasonbc]

The 12T will make it a bit less likely to bog down at low rpm but the smaller sprocket may make the sudden "scalded cat" effect worse. Going from the XR to the Gas Gas is bound to require a bit of time to adjust as the power delivery is so different.

There are different FMF front pipes and some are tuned for peak power rather than low to midrange. Hopefully the pipe has its identity stamped onto it as the power core 2 only refers to the silencer. You may have one fitted that's more top-end focused.

Better get used to it quick then as it's entered in a South west Championship Enduro on the 4th of October and it the first competion for me on the bike. As for the scalded cat thing it had that with the 13t sprocket

[jasonbc]

The 12T will make it a bit less likely to bog down at low rpm but the smaller sprocket may make the sudden "scalded cat" effect worse. Going from the XR to the Gas Gas is bound to require a bit of time to adjust as the power delivery is so different.

There are different FMF front pipes and some are tuned for peak power rather than low to midrange. Hopefully the pipe has its identity stamped onto it as the power core 2 only refers to the silencer. You may have one fitted that's more top-end focused.

Just checked my pipe it's an

FMF GOLD SERIES FATTY PIPE 80 CALIF (WHATEVER THAT MEANS)

[AlanH]

I can't find any dyno charts for it. I think what you could be looking for is a Gnarly. Check out the manufacturers info...

FMF Racing - Pipes

A Gnarly would probably take the edge off the top end and give a stronger low to midrange.

[jasonbc]

I can't find any dyno charts for it. I think what you could be looking for is a Gnarly. Check out the manufacturers info...

FMF Racing - Pipes

A Gnarly would probably take the edge off the top end and give a stronger low to midrange.

Was just looking at that page as you replied does look that way but will see how we get on with it. The system is new by the look of it and doesn't warrent replacing it at that expense at the moment. JUst need to practise more and get used to it more

[jasonbc]

JUst tested with the smaller front sprocket it has made a huge difference to the performance of the bike and is a lot more rideable now. JUst got to find a load of steep slippery climbs and practise now

[ritosxf]

rush racing in yeovil used to be the kiddies on the block for all uk fmf stuff
but they have given it over to oro in wales now , rush racing are now called one industries europe , and just do oneindustries stuff , so if you need any help with your fmf system , contact off road only in llandridrod wells wales , www.oro2u.com