JSM reusable gaskets

nopdog

nopdog

VIP MEMBER
Joined
Apr 24, 2017
Messages
358
Country flag
Trying to fix an oil leak from inner gearbox joint. I have a set of JSM gaskets to fit (fibreglass impregnated silicone) the notes say no sealer necessary. What are your thoughts gentlemen, with or without sealer. If with what kind.
Very nice gaskets btw.
 
Never used any sealer myself , only the very lightest smear of grease . Do as instructed . I have silicone type valve cover ones .
 
They can be difficult to keep in place while installing the part. I am going to start using spray Coppercoat on the inner surface of the gasket to temporarily hold it in place as the outer part is applied. Spray a liberal coating on the inner surface only. Allow it dry until it is tacky, then place it accurately and press it onto the surface.

When it comes time to remove the part, the gasket can be peeled off, cleaned with brake cleaner and reused.
 
You'll find that the fiber reinforced silicone gaskets aren't nearly as floppy and squishy as the plain silicone ones.
 
I think I have every fiberglass reinforced silicone gaskets offered for the Norton commando.

I have said gaskets on the transmission inspection cover, inner and outer transmission cases, rocker covers, rocker spindles, and oil feed lines. While some of these are a bit fiddly getting them to stay in place, when it came to installing the timing cover, it was near impossible to keep the gasket in place while installing the cover. It took a lot of fiddling and fishing to get it in place as we tightened down the screws.

I'm going to be removing the timing cover to investigate some oil pressure issues and I will use the spray copper coat as mentioned in my previous post to hold that gasket in place. Furthermore, I think I will do the same on any of the other fiberglass reinforced silicone gaskets if I have occasion to remove the parts they seal.

BTW, I highly recommend the fiberglass reinforced silicone gaskets.
 
Last edited:
Install the screws, Lean the timing cover on something to keep it upright. Then push the gasket over the screws one by one and assemble. Forget using sealer. Same with the Mk3 primary cover.

JSM reusable gaskets
 
Last edited:
jseng1 said:
Install the screws, Lean the timing cover on something to keep it upright. Then push the gasket over the screws one by one and assemble. Forget using sealer. Same with the Mk3 primary cover.

JSM reusable gaskets
Click to expand...
Even with all the screws started the thin portion at the top rear of the case (top right in the photo) was hard to keep aligned properly despite having used grease to adhear it to the case .
 
I also got Jim`s gaskets in gearbox and for rockerbox covers....what I always use for 0-rings, rubbers or these silicon gaskets is silicone grease. holds gaskets in place and is for sure good care for silicone and rubber products......
 

Similar threads

Fast Eddie
Silk thread for gaskets
2
Replies
24
Views
997
jseng1
jseng1
George Hirvela
silicone amc gearbox gaskets
Replies
15
Views
762
TomU
TomU
concours
T160 rocker box gaskets
2
Replies
21
Views
975
Onder
Onder
W
Cometic Gaskets
Replies
14
Views
1,108
MichaelD
M
jseng1
500 600 650 Domni head gaskets
Replies
3
Views
359
jseng1
jseng1
Back
Top