Author Topic: Cometic gaskets  (Read 1014 times)

Offline coater87

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Re: Cometic gaskets
« Reply #15 on: 29.05. 2017 05:30 »
 I was talking to a friend who said a few months Back he sliced his palm open on the edge of one of these gaskets. 6 stitches I guess.

 He swears by them but says you have to be carefull, the edges are very sharp especially if they pooch out and are exposed after install.
Central Wisconsin in the U.S.

Offline worntorn

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Re: Cometic gaskets
« Reply #16 on: 29.05. 2017 15:27 »
Makes sense, and they are also nasty to trim if needed. A razor knife and patience are required. But once fitted they sure dry the bike up.

Cometic will have profiles on all of the A10 gaskets I sent them, should other A10 owners want to give them a try.
Drew at Cometic said they already had some of the A10 info from previous orders. They also have profiles for some A65 gaskets.

The gaskets he is sending are 32 thou thickness. I don't know why my Vincent gaskets measure at 44 thou, they don't list that thickness.


Glen

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Re: Cometic gaskets
« Reply #17 on: 29.05. 2017 17:59 »
OK, I admit that I do not thrash my A10 * but my machine doesn't leak oil. I use Blue Hylomar, sometimes only on one side of the gasket. I'm pretty sure that Hylomar would seal just as well on its own. I made sure that mating surfaces were flat during rebuild. I do not use Allen screws/bolts; just slot-head screws. Surely my machine is not unique.




* I also have to remind myself that the bike was off the road for forty years so has not had the constant abuse that some of these bikes have had.

Offline worntorn

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Re: Cometic gaskets
« Reply #18 on: 29.05. 2017 20:57 »
I guess the main benefit is the Cometic's ability to seal a much less than perfect surface without any type of goop added.
There is also the ease of removal and reuse, plus these gaskets do not accidentally tear as paper gaskets do. This was a very nice feature when I had to remove my Vincent primary cover roadside, 1500 miles from home.

Offline shabashow

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Re: Cometic gaskets
« Reply #19 on: 04.06. 2017 18:15 »
I've used copper gaskets on my rocker boxes and am very pleased with the oil tight results and reusability after annealing. I think they'll stand higher temperatures than anything coated in nitrile rubber.

Offline duTch

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Re: Cometic gaskets
« Reply #20 on: 04.06. 2017 21:29 »

 Something that occurred to me while taking of my Timing cover the other day, is that some of the mating surfaces are thin (narrow) and don't mate evenly, in that they overlap each other.
 The main culprit on mine is the joint between the Generator Drive chamber and the Oil Pump, which was only about 5mm wide, and mated for about half of that.
 To rectify it I had a bead of weld done on the oil-pump (under)side and dressed it down.
 It seems to have done the trick
 
 I expect the Cometic gaskets would be wide enough to cater for this, but something worth keeping in mind and checking your own.
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Offline worntorn

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Re: Cometic gaskets
« Reply #21 on: 09.06. 2017 21:17 »
The Cometic gaskets have been shipped so Cometic now has most 57-63 A10 gaskets on file.
I added a 1975 Commando primary gasket to the order as they already had the info for that. To be sure we were talking about the same gasket, I took a pic of a paper version I have had in storage for a few years. The paper gasket broke in two places while handling it.
The material has become very fragile even though it was stored flat and in a drawer.
This is one of the big advantages to the Cometics, they do not seem to degrade and will not break from handling, even accidental rough handling.

The total cost for the order was $141US.
Tappet cover gaskets are $7 each. The outer timing cover gasket was $28, so they are a bit spendy, but well worth it in my view.

Glen