Does anyone know if the 1978 XS650 Rear MC rebuild kit will work on a 77 XS400D?

Yamaha part for the

77 XS400D is 1U4-W0042-50-00

78 XS650E is 1J3-W0042-50-00

Close but not quite an exact match..

The pics on the kit from Mikes XS look correct..

If I knew the bore size of the XS650 part it might help.

Or maybe someone can help me figure out what is wrong with the one I have..

It holds fluid and isn't leaking..

It will pump fluid but will not pull in fresh fluid from the resouivor.

I've stripped it down and cleaned all the passages..

when it's dissambled fluid will drain from the resivour into the cylinder bore.

The bore looks good.. No pitting..

cleaned passage from Resivour to cylinder bore.

I've cleaned the little passages in the piston but the little spring valves don't make a good seal.

I'm assembling as follows.

Sping.. large end first, small capped end facing out

Rubber cup lip first.. flat end facing out.

piston, valve end facing rubber cup

retainer washer

lock ring.

you can still get the kits from yamaha, but they are expensive (£45 2 years ago) although I did buy a kit from Uttoxeter VJMC show for a £5.

http://yamaha.motogrid.com/pages/parts/vie...d/2/yamaha.aspx still do them $62

http://www.bikebandit.com/houseofmotorcycl.../m8254sch214280

for same price

have you cleared the slurge hole? its a tiny thing and you will need a pin to clean!!