Pretty sure that is a suitable substitute for Yamabond 4, Suzi, Kawi, Honda, all Threebond 1184 from Japan.Permatex Moto-Seal. Used it on everything from two cylinder Nortons to 12 cylinder Detroit Diesels! Moto-Seal is NOT a silicone (tool of the Devil)!!
That's what Evinrude recommends on my Etec 150 outboard. Worked fine for me.Permatex Aviation Form-A-Gasket seems to be very similar to Heldite.
Have you used them on the MK111 primary? If so for how long? I would like to know the long term effectiveness, ie leakes.I don't know the earlier Commandos, as mine is a mk3. For the mk3 there is a silicon gasket available: https://jsmotorsport.com/product-category/norton-gaskets/. This was to be my next attempt, if the grease didn't work.
Might be worth making contact to see if something similar might be made for the earlier primary covers?
Edit: they are reusable, I have them on my tappet covers.
Well, $37.00 delivered for one MK111 gasket is kind of steepI can't imagine going back to sticky Silicone type sealants anywhere there is a gasket. I went a little crazy and had Cometic make a complete set for the BSA A10, three sets for the Vincent twins (2 now in place) and a set for the Norton Commando MK3. I ordered a dozen of the intake stub type gaskets as they work so well to seal that up without having any sticky stuff that requires removal for reassembly.
The Vincent people tend to be really old and set in their ways, but they have almost all gone over to these Cometic Nitrile/ Aluminium gaskets. A member of the Chicago club made us aware of these gaskets about 15 years ago. At first they just had one or two Cometic gaskets available foe the Vincent but now complete engine sets are available.
I posted info about the Cometic gaskets on the A10 site and the response was " My bike doesn't leak a drop with paper gaskets. And I can reuse them easily"
Yeah, right.
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I'm holding up a very skinny A10 gasket by one point and it keeps its shape. It will also do this after many reuses. Try that with other gasket types.
I would order some additional items to go with it. You can fit a lot of gaskets into one $20 flat rate box, or just one primary gasket.Well, $37.00 delivered for one MK111 gasket is kind of steep
At Pokes Cycle we used Yamabond/Hondabond/Threebond on many joints and it did stop leaks. We used RTV silicone on the rubber band on pre-MKIII primaries, letting it set up before adding oil. Since removing the primary cover was/is a regular service procedure when cleaning clutches, anything more permanent seems ill advised.Pretty sure that is a suitable substitute for Yamabond 4, Suzi, Kawi, Honda, all Threebond 1184 from Japan.
All great stuff.
I get my supplies and parts from Fair Spares New England, fair price and no shipping.I would order some additional items to go with it. You can fit a lot of gaskets into one $20 flat rate box, or just one primary gasket.
The intake stub gaskets are sure nice to have as are the rocker cover gaskets. I was told that Cometic has gaskets for the entire engine /trans.
If one wanted to order a paper MK3 primary gasket from Andover the shipping cost to me is about $35 for the cheapest option or $130 cdn for speedy service. Same thing though, they could fill the box with gaskets for the same shipping cost.
Glen
Have you ever drained and measured the amount of oil in the primary. If the crankcase is wet sumpted and the inner primary screws allow that to leak into the primary, you may have way too much in the primary.I have a leaking primary case problem (1973) that I have battled for while.
It does not leak when I put the seal in, with sealant, let set and then fill with oil.
I use sealant along the bottom face. (I have tried blue silicone, Permatex The Right Stuff and Permatex Optimium Black)
I can leave it for weeks and it will not leak.
But when I take it for the first ride, it leaks from the bottom and every ride thereafter.
I have properly shimmed behind the case where the bolt tightens the
cover to the inner primary.
When I lay the cover on the inner primary case without a seal, it is flush everywhere
Would really appreciate your thoughts
Thanks
Dennis