Softening The Power Of A 270

[mikee]

Bit of an update on this one.

Took the engine out and I started with one extra base gasket to see how this would affect the low down power. You could tell just by the exhaust note that it was a bit softer. Rode the bike for about two weeks and did one trial like this and found the bike a lot more manageable.

So took the motor out again and put another base gasket in (3 in total now).

I have not changed anything other than adding two base gaskets and now the bike is very good to ride. The power comes from right off the bottom of the of the rev range and is very smooth and talky. The exhaust note has a lot less of a crack to it now. The bike finds grip in the mud with out spinning out now and does not try to tear your arms off when things start to go wrong...

Might go the other way in a year or two and fit a racing thin base gasket, take the flywheel weight off and fit a fast action throttle, but for now I

Edited April 15, 2008 by MIKEE

[billytraynor]

Mikee

One of the best ways to calm the bike down and a very tunable way is add a

reed spacer plate. Start off with 5/16 thick and work you way down from there.

Meaning try it at one thickness and then surface grind to another takeing off small increments at a time.

Place it between the reeds and cylinder. It will make the compression lower due to increasing cylinder volume.

This trick has been used for years and is proven to quite successful.

It does not change any port timings.

There are numerous other advantages that it offers that will off topic so I will not go in to them here.

Cheers

BillyT

Edited April 20, 2008 by BillyTraynor

[tg91]

hi i have a 06 rev3 with the standard 250 set up , i would like to make up to the 270 spec . i would be happy to do a swap / trade up to a 270 .can any one help , or tell me ware i can buy the parts that i will requier , many thanks glenn

[peterb]

Hi subanator,

You've got it sussed. Inserting extra base gaskets does not increase the primary compression, it does raise the ex. port (shifting power higher up the rev range) and decreases the compression ratio, lowering power slightly. The inlet is controlled by the reed valve opening under vacuum as the piston descends, drawing in a fresh charge of fuel/air. 2 strokes benefit from as high as possible primary compression which is another reason that GG have the oil seals on the inside of the crankcase, more efficiency in the primary compression.

Bye, PeterB.

[subanator]

Thanks PeterB, for the comments.

Mikee, good to hear you like the change, enjoy the ride. I have seen riders in a higher grade riding with this mod cleaning up a grade title in my club.

But just try and ride the bike without the added gaskets when you get to a higher grade, go easy on any mods the other way, you have to first master it before modding it!

Edited April 22, 2008 by subanator