Paper Gasket or Form-A-Gasket for Crankcase

#1
I am rebuilding a Sachs Saxonette 50cc 2 cycle engine for an Arctic Cat. I bought a complete NOS gasket and seal kit but after sitting on a shelf for 40 years, some of the larger, thiner gaskets have curled and twisted. If you are familiar with that engine, you know that there are 2 large but very thin and complex paper gaskets between the crank case halves and transmission cover.

What's the best way to get those gaskets in the correct location while I put the halves together? Would I be better off using Permatex Form-A-Gasket on those 2 complex surfaces, especially the crank case halves where the gasket is open-ended?

I read on the Permatex site that the last thing I want to do is use the Form-A-Gasket to stick the gasket to the surface. Apparently that's a guaranteed leak waiting to happen as their product requires metal to metal contact for proper curing.

Will Form-A-Gasket work fine for the crankcase halves or should I try to get the paper one in place at all costs? Advice? Tips? Tricks?

As for straightening out the curled paper gaskets, anyone ever tried carefully ironing them or maybe wipe them with a damp rag and letting them sit under a heavy book?
 

banjo

New Member
#3
Yep hondabond4 as texasfabguy said. I am only chiming in to let you know hondabond ,threebond and and other comparable products are crankcase sealants not at all like gasket peanut butter.
 
#4
Yep its good stuff, I have used it for years. I like to put it on and let it sit for a minute or two till it gets a good skin on it then put the parts together.
 
#6
In the official Sachs service manual for this engine, it says a number of times that certain surfaces should be coated with gasket sealant prior to adding the paper gasket.

For example, when assembling the 2 crankcase halves it says:

"Coat both of the mating surfaces with sealer (we recommend the colorless gasket sealer no. 40, F&S order no. 0999 107 000)".

It then instructs you to lay the gasket on it and assemble the halves.

Anyone got any suggestions of a modern equivalent to this "colorless sealer"? I found one posting on a snowmobile site where "copper seal" spray was used. It looks like it's a product designed to help paper gaskets seal better rather than something to replace a gasket, like Form-a-gasket or Hondabond.

Anyone use this or have a better product to suggest?
 

jrzmac

Active Member
#7
I had the same thing happen to my Tecumseh. I pulled the side cover, and when I tried to put it back, it just kept leaking. It wasn't pouring out, but it would drip every so often. The only thing that stopped it was I did what you said. I used Permatex Gasket Sealer on both the cover and the block. A tiny bit, just a light coating, and then let it dry for like a half hour. Then I put the gasket on the block, then put the side cover on. tightened all the bolts down and let it set for like a day or two. Never leaked again! I watched this guy do it first:

CONNECTING ROD Repair On 9HP Tecumseh Snowking PART 2 of 2 - YouTube
 
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