Anyone know what a SP should be showing PSI wise, for a healthy cylinder?

Cheers.

Can't remember the exact figure and I don't have the manual to hand but it's around 8 bar, or 116 PSI

thunderace wrote:Can't remember the exact figure and I don't have the manual to hand but it's around 8 bar, or 116 PSI

Cheers for that. Thought it would have been a touch more than that, but will use it as a reference and pray that all four are consistent with one another.

When you say 'manual', where did you get a GSXR-400 manual from? Is it in English, or Jap?

Hello again,

Right, have done the test and have 137 PSI in number 1 and 2 (working from left to right) and 20 PSI in number 3 and 4.

Anyone thinking I might be lucky and the head-gasket has gone, or am I being optimistic? Both number 3 and 4 are giving the exact same reading of 20 PSI, so they must be sharing, surely?

Any thoughts?

Cheers.

Not too sure whether 137 PSI is all that good either, would have preferred over 150 PSl. The motor was cold and dry though. Will try them with a touch of oil.

With a drop of oil in number 1 and 2 it goes up to 175 PSI, 38 PSI difference.

I'm finding a great deal of parts (discontinued) are exactly the same as the GSF400! Does anyone know whether the GSF-400 pistons are the same as the GSX-R400?

Yes mate. same pistons.

Variablevalves suck wrote:Yes mate. same pistons.

Ah, that is good to know as the 0.4 oversize seem to be readily available. I am thinking of reboring it and going for the 0.4 oversize. Not too keen on the compression readings and the difference the oil made tells me the rings/bore is not too good. At the moment I have this lined up:

Cam cover gasket 11173-30B02 £25.00
Base Gasket 11241-32C00 £12.22
Head Gasket 11141-32C10 £30.61
GSF400 Piston kits 00.40 12100-32C00-040 x4 £111.13 Robinsons £75.50 CMS
Gudgeon Pin 12151-32c00 x4 £11.50
Circlips 09381-16001 x4 £1.00

Gonna be over £450.00 with the rebores. V.V.S, have you any experience with the top end of these motors and have you any advice on it?

Cheers.


P.S. Should really replace the valve seals as well.