Hi, I am continuing with rebuild of M-80 engine and would like to know types, quantities and sizes of seals required when replacing both outer casings. There is also a fibre washer to fit behind clutch arm stem on casing (missing when stripped down) is it a standard size? When I reassemble is Blue Hylomar ok instead of paper gaskets?

Cheers

Paper gaskets and clear silicone.

Hi

We all have our own preferences on rebuilds and whether to use sealant or not.

Simply put it depends on the quality of the machined faces.

In my case on the M80 engine I just rang Bultaco uk and got a complete set of gaskets, seals and bearings, simple.

In my research I did suspect that some of the gasket sets available were too generic and did not include all the bits.

On final assembly I just spread grease along the mating surfaces, this has three purposes 1) it holds the gasket in place 2) it allows me to strip the engine down without having the scrape goo off the surface 3) I may be able to use the gasket again if I have the do a field repair.

Back in the sixties on my Greeves ( Scottish, TES, Anglian) I used Wellseal as it came off easily.

Hope this helps, but there are many ways the skin a cat.

Martin

Cheers, Looks like a gasket and seal set from Bultaco UK, I may still use Hylomar as it is non setting and can be seperated and rejoined and retain its seal,

Good advice as usual,

Thanks