250 to 300 Conversion
- Thread starter Kurdt
- Start date
gasser
New member
Go to www.gasgasmotos.es then click on Selección Idioma in the upper right corner. That will give you a drop down menu where you can select English. Next put your pointer on motorcycles and select manuals from the menu that pops up.
You need:
cilinder,
piston,
rings,
Piston pin,
piston pin snap rings (2),
Piston bearing.
cylinder gasket,
head,
head Orings,
Head water hose gasket,
Reed Valve spacer.
Reed valve gaskets (2).
You also need to take the power valve from the 250 and place into the 300, I would recommend to replace PV bearings too.
have fun,
j.
cilinder,
piston,
rings,
Piston pin,
piston pin snap rings (2),
Piston bearing.
cylinder gasket,
head,
head Orings,
Head water hose gasket,
Reed Valve spacer.
Reed valve gaskets (2).
You also need to take the power valve from the 250 and place into the 300, I would recommend to replace PV bearings too.
have fun,
j.
2 strokes 4 life
New member
Another option is Eric Gorr at Forward Motion in the USA. Makes a 275 big bore kit. Only $400 I think.
Don't know if he did it, but I did a 300 to 250 conversion. Easy as it could get. Piston pin, bearing, clips are the same. Only the inner cyl head O ring is different. I left the reed valve spacer in with the 250 setup. Anyone know why it should be removed ? It runs and idles excellent with a lot less surging and chain slap when just cruising.
Didn't even have to change jets (yet), just a tweak of the air screw and idle, and richened the LTR needle 1 clip. Funny it seems to be running leaner as a 250.... maybe the modded head it came with makes it flow more ??
stay_upright
New member
cdn - why did you change?
Several reasons. But mostly:
- I found a very reasonably price 250 top end, so why not have a spare
- I had moved from a 280 trials bike to a 250 and my riding skills instantly improved. Probably with the extra traction gained with the softer power. Guess thats why the extreme enduro guys use a 250 more often than not. A bit more forgiving but the same power is there if you wind it up a bit more.
- this aging body was finding the instant mega off idle power of the 300 a bit tiring at times. Usually late in the day when trying to avoid the singletrack trees with the slightest crack of the throttle or multiple attempts trying to find traction on hills and in the real slow slick stuff.
