AJS & Matchless Owners Club

The workshop manual I have ( red , Workshop Instruction Manaual All Models) states that no head gasket is used ( page 37).
This chapter is about the scrambler engine but I believe that in essence this is the same as the 250 .
In other chapters a head gasket is mentioned but it is not clear whether it's function is to provde a seal between the barrel and the head ( as in combustion chamber or just to provide oil tightness between head and cilinder unit . Or both.

My 250 CSR ( with compression problems ) came with a thin copper ring on top of the barrel which fits in the recess along the edge of the combustion chamber .

Sooo : do I put some sort of seal between barrel and head to provide gas tightess or do I just lap head and barrel in to each other and just make a gasket to prevent oil leakage from the head /barrel joint ?

Many thanks in advance for your replies

Maxim Jurgens
Phuket, Thailand

My 1965 csr came with a thick composite/copper gasket- the new engine gasket set included one the same

Just use the standard thick composite copper gasket that comes in the gasket sets. Nothing special needed on a 250CSR.

Stretching my memory, I just used the standard gasket in the packet on my 14CSR.

Clanger, just looked up your Moto Morini - they're lovely and I'm jealous.

Johnny B

@Johnny B thank you! They're rare beasts, but they're a lovely little bike...