Stihl base gasket install dry or sealant.

[FernGreen]

I know what you're thinking... "oh god another sealant thread"
I just want to know:
1.) when using a new oem base gasket do you guys find that they seal fine dry or do they need a little sealant to seal correctly? This is for my 044 top end end rebuild.
2.) If i do need sealant can i use the motoseal (made by permatex) that i have sitting on my bench?

 

[Woodslasher]

Dry always works for me, but I like to put some Copper Coat on them for added insurance. I dunno about motoseal, sorry.

 

[ammoaddict]

Motoseal is good stuff. I have used it with no base gasket. Still holding up.

Sent from my moto g(7) power using Tapatalk

 

[FernGreen]

Dry always works for me, but I like to put some Copper Coat on them for added insurance. I dunno about motoseal, sorry.

Motoseal is good stuff. I have used it with no base gasket. Still holding up.

Sent from my moto g(7) power using Tapatalk

Thank you guys! I might give it a shot dry first seeing as I already have the gasket.

 

[BangBang77]

I always install them dry first. Vacuum / pressure test once assembled. If needed I add some sealant to the gasket, re-assemble and repeat tests.

 

[Deleted member 117362]

If you use gasket with Motoseal and let it cure for 24 hours, then decide to remove cylinder. You will be scraping gasket and sealant off, removing cylinder may take a little effort. I like using it with case gasket, no oil leaks.

 

[ammoaddict]

I haven't used it, but I have heard very good things about the hylomar blue. Gasoline resistant, no cure time, easy removal and clean up.

Sent from my moto g(7) power using Tapatalk

 

[drf255]

Dry, with the bevels on the metal gasket up.

Thats the beauty of those rubber coated metal gaskets. No sealant to deal with and easy pulling/reassembly of the jug when needed.

 

[cuinrearview]

I feel like sealant is just a band aid for damage to mating surfaces or poor surface prep. If everything is clean and smooth a dry gasket is all that should be needed.

 

[Wood Doctor]

I feel like sealant is just a band aid for damage to mating surfaces or poor surface prep. If everything is clean and smooth a dry gasket is all that should be needed.

Along with four tight bolts. A sawyer brought in an MS 660 saw and said, "Edwin, it's not running right. See what you can do."
One of the cylinder mounting bolts was missing its head and one of the other ones wasn't even thumb tight. Frankly, that was the first time I had seen that. Gasp!

 

[zeroskater58]

Dry, with the bevels on the metal gasket up.

Thats the beauty of those rubber coated metal gaskets. No sealant to deal with and easy pulling/reassembly of the jug when needed.

newbie question, as im getting ready to swap my ms660 aftermarket top end back to oem, do you mean the 2 humps on each side of the gasket are up? with them down, it looks like they fit into the crankcase nicely, any reasoning behind them going up? just curious

 

[Vintage Engine Repairs]

If in doubt permatex no 3, I have only ever had one cylinder gasket leak and that worked fine to fix it. There was a tiny leak around one of the bolt holes but a few heat cycles would have taken that up.

 

[RED-85-Z51]

I feel like sealant is just a band aid for damage to mating surfaces or poor surface prep. If everything is clean and smooth a dry gasket is all that should be needed.

But sometimes a bandaid is reasonable. Ive seen some truly ham fisted efforts to remove old gaskets that left the mating surfaces in bad shape, maybe it would seal, maybe not...but a thin film of sealer can at least raise the odds of a good seal. Some 4 cycles dont even use gaskets at all anymore to deal valve covers and cases...relying solely on sealer...it does work well if applied right.

Sent from my LM-G820 using Tapatalk

 

[cuinrearview]

But sometimes a bandaid is reasonable. Ive seen some truly ham fisted efforts to remove old gaskets that left the mating surfaces in bad shape, maybe it would seal, maybe not...but a thin film of sealer can at least raise the odds of a good seal. Some 4 cycles dont even use gaskets at all anymore to deal valve covers and cases...relying solely on sealer...it does work well if applied right.

Sent from my LM-G820 using Tapatalk

"damage to mating surfaces" is in my post that you quoted

 

[RED-85-Z51]

"damage to mating surfaces" is in my post that you quoted

I know, im reiterating your point that while its not always required it does its job well when needed.

Sent from my LM-G820 using Tapatalk

 

[drf255]

newbie question, as im getting ready to swap my ms660 aftermarket top end back to oem, do you mean the 2 humps on each side of the gasket are up? with them down, it looks like they fit into the crankcase nicely, any reasoning behind them going up? just curious

Stihl manual states they go up. I’m not certain why it matters, but flattening when up would yield a flat gasket.

I also did down for years without any issue. Seemed easier to follow what the OEM said.

 

[zeroskater58]

Stihl manual states they go up. I’m not certain why it matters, but flattening when up would yield a flat gasket.

I also did down for years without any issue. Seemed easier to follow what the OEM said.

huh, the wording in the manual i have says "curvature down" whatever that means exactly, guess its not super important, thanks