Gasgas Jtx 270

[graeme]

Hi

I have just bought a jtx 270 1997 i think

it has got a bottom end rumble, previous owner fitted new piston and ring i think

it has loads of compression which backs this up

I am interested at what my options are for a rebuild

it has pay in fly wheel

i must say i am new to the forum so not sure if you can give names of supliers

i use a trials shop in stroud

thanks graeme

[copemech]

Let them put some new bearings and seals in it! Send them just the motor if you can, as most any reputable shop can do it quickly and get it back to you. Do you have local references?

[graeme]

ive managed to get the engine out and split the casings

one of the mains had lost its bearing retainer Con rod seams fine

I will change mains and small end is their any others i should change whilst i am doing it

the other seam fine but if they are cheap enough i mite as well do a proper job

[copemech]

I'm no Gasser expert, but the only things that come to mind would be the seals on the water pump and possibly the output shaft(chain) gear, as these are common wear items on any bike over time.

[peterb]

Hi Graeme,

Best to replace both main bearings, make sure they are the correct clearence. Should be a type 6206 C3 - C3 being the clearence designator. Fit new crank seals and centre gasket. As copemech advises, it's a good idea to replace the water pump seal and quite likely the water pump shaft as these tend to groove out. There is a seal/shaft kit available for these.

Don't forget to refit the ball bearing after the clutch pushrod.

Refill the gearbox oil with 700ml mineral oil, 10 weight or an ATF rated to Dexron III.

Bye, PeterB.