Head Gasket

[Christian Raith]

Phet phet phet Check the exhaust header  or the exhaust header seals. Had it happen to me and I thought the worst
Me header pipe had a small crack in it at the join.

[Christian Raith]

Could be a small leak from the cam chain adjuster.
Always start with the easy stuff much easier to correct

[Cooper]

Thanks for replies. Not that sure about head gasket but it starts easy enough, when I did. compression test I got 135.125.125.135. I noticed a slight weeping of oil from lower cylinder on my last ride.  Had Good look around cylinder head that looks ok no sign of leakage there. Is a bit unusual for lower gasket to go?

[steptoe]

I'm with Pete, what makes you so sure it's a head gasket,,
    is there a sound like air being pushed thru every time a piston comes up?? sort of like a phet phet phet,
       is it really hard to start cold,
compression was 130, what is it now, and how many are down now,
       
in my experience a head gasket by itself approx 150-180$,,,complete engine rebuild kit about the same with many more seals gaskets,,

head,, base,, sides,, sump,,umbrella seals { valve stem },, top cover

be sure it's the head gasket first !!!!!!!!!! cause if your going to tear into it,, with the price of gasket by itself there are lots to check and clean up while it's off.

[petejw1966]

hi cooper,
what makes you think you've blown the head gasket?
id leave the rings alone but if you do replace the head gasket,
while you have the head off and cams removed, tilt the head on its side
and fill the ports with petrol and see if the valves are sealing properly,
there should be no seepage, do this for both the intake and exhaust valves,
also as chris stated changing the cam chain wouldnt hurt either.

[Christian Raith]

I would be checking why the head gasket blew first
What cylinder and check the exhaust valve there, just a thought. maybe a new cam chain while you are at it
130 is good so rings are probably ok
Just read the book about getting the head off before you do it or ask on here, lots of knowledge floating around the UK and AUS site

[Cooper]

Hi all just returned from TT races with my son great 10 days only had one wet day unfortunately two riders died. Will post some pics of some older classic bikes we saw there. Didn't see one XS anywhere. Infact speaking to one bloke who used to own one very few appear for sale in UK or they are snapped up quick maybe values will increase similar to CBs.
Just changing the subject before we went away I blew a head gasket on my 78. Was running sweet prior to that compression was around 130 on all cylinders. Ive never had to work on an XS before other two  Ive owned ran sweet. Should I just replace head gasket or do rings as well  I dont want to spend to much money but at the same time do you think the compression is OK for just a new head gasket regards Coops.