# Cylinder base sealant, expensive Stihl silicone or hi temp red RTV ??



## kspakland (Nov 21, 2011)

I am going to re-ring and freshen up a friend's MS310, and since there is no cylinder base gasket, I see where Stihl uses a red silicone.

Do I REALLY need to buy the expensive Stihl brand sealant, or can I use standard high temp red RTV silicone?

Also, any suggestions you guys may have regarding the "freshen up" would be appreciated.

Since the crank seals appear good and there are no issues there, I don't see the need to take the crankcase apart.

Just new rings on the top end, new gaskets where needed, new fuel lines and a carb kit.


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## lone wolf (Nov 21, 2011)

Yamabond ids the best stuff out there.Should be 7.00.


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## Brian VT (Nov 21, 2011)

lone wolf said:


> Yamabond ids the best stuff out there.Should be 7.00.


Yamabond 4.


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## Jacob J. (Nov 21, 2011)

My vote is for Yamabond as well. The old-school Dirko that Stihl sold was the same grey sealer as Yamabond, which resisted fuel and heat really well. The newer red Dirko that Stihl sells isn't much better than red RTV. 

RTV silicone is not good for sealing engines. If you don't have access to Yamabond or a decent bike shop nearby, then that Ultra Copper or whatever it's called, will work.


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## Saw Dr. (Nov 21, 2011)

I paid the $20 for the Dirko, and have never had one come back with the sealant leaking. $20 is not that hard to absorb in 1 or 2 rebuilds. 

Whatever you use, make sure it is fuel-proof. Many RTV type sealers are not. The bottom end of that engine will be in constant contact with fuel. If that sealant leaks, you will have an air leak and possibly a scored top end very soon.


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## Fish (Nov 21, 2011)

kspakland said:


> I am going to re-ring and freshen up a friend's MS310, and since there is no cylinder base gasket, I see where Stihl uses a red silicone.
> 
> Do I REALLY need to buy the expensive Stihl brand sealant, or can I use standard high temp red RTV silicone?
> 
> ...



You will definitely be taking the "crankcase" apart.....


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## Fish (Nov 21, 2011)

When you remove the engine from the plastic crankcase, it will look like this......



Stihl MS290, Engine Long Block , NEW | eBay


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## OH_Varmntr (Nov 21, 2011)

High-Temp Red works if you have no access to Yamabond.


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## Brian VT (Nov 21, 2011)

Fish said:


> You will definitely be taking the "crankcase" apart.....


Yah, 310 is clamshell.


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## Fish (Nov 21, 2011)

Brian VT said:


> Yamabond 4.



I prefer "Lethal Weapon 3".....


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## Nitroman (Nov 21, 2011)

ThreeBond, Evinrude crankcase sealant same stuff, all essentially same stuff. I use Three-Bond cause I have lots of it since I rebuild snowmachines often.


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## dave_376 (Nov 21, 2011)

A few years ago I was looking for yamaBond and had trouble finding it. I ended up with ThreeBond, it looked the same and I never had a problem with it. If I was shopping for a new tube now I would look for yamabond


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## russhd1997 (Nov 21, 2011)

I started a thread like this yesterday asking about sealer for a MS180 crankcase. One of the responses to that was Hondabond which is the same as ThreeBond and Yamabond. I googled "Hondabond substitute" today and found that Permatex Ultra Grey is the same thing.


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## Bowtie (Nov 21, 2011)

I have been using the John Deere white sealer they use on their diesel engines for a while and it has been working very well. 10 bucks a tube and it is fuel/oil proof. It is very good stuff. Just another alternative...


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## Fish (Nov 21, 2011)

whatever.......

about any sealer will do....


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## ol'homey (Nov 21, 2011)

Anyone tried good ol' Permatex 2B ? I've used it on a lot of things including in place of a base gasket on a couple of old Homies without any problems. It's fuel/oil resistant. I just put a thin coat on both surfaces, wait for a few minutes to let it get tacky and put 'er together. I know it's not as good as the stuff mentioned so far, but it is available at any parts store and it hasn't failed me yet.


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## Brian VT (Nov 21, 2011)

Nitroman said:


> I rebuild snowmachines often.


I wouldn't think that you'd need to make snow in Alaska.


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## Wicked500R (Nov 22, 2011)

I just went to my local cycle shop to get Yamabond and the dude handed me Yamabond 6.. I hope its the right stuff....


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## Slamm (Nov 22, 2011)

I used Threebond 1211, has worked on 3 saws now with no issue.

Sam


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## nmurph (Nov 22, 2011)

No, you want 4..

Yamaha Motor Corporation, USA - Adhesives & Loctite® Yamabond 4 Motorsports

vs 

Yamaha Motor Corporation, USA - Adhesives & Loctite® Yamabond 6B (Black)


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## wyk (Nov 22, 2011)

Slamm said:


> I used Threebond 1211, has worked on 3 saws now with no issue.
> 
> Sam



Nice. But you'll have to switch to '_Fourbond_' and '_Fivebond_' for your next couple of saws...


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## Slamm (Nov 22, 2011)

wyk said:


> Nice. But you'll have to switch to '_Fourbond_' and '_Fivebond_' for your next couple of saws...



Yes, it appears it will come to that. I only used very little of out of the tube of Threebond and now I'm going to have to get rid of that tube and now get a Fourbond and so on consecutively higher. Hopefully they sell it in smaller quantities, otherwise this is going to get expensive, LOL.

Sam


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## Wicked500R (Nov 26, 2011)

What about the Threebond 1194 Northwood Saw sells? Is that the right stuff?


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## mopar1rules (Nov 26, 2011)

russhd1997 said:


> I started a thread like this yesterday asking about sealer for a MS180 crankcase. One of the responses to that was Hondabond which is the same as ThreeBond and Yamabond. I googled "Hondabond substitute" today and found that Permatex Ultra Grey is the same thing.



Correct. Hondabond, Yamabond, Threebond 1104, Threebond 1194 (subsituted 1104), and Permatex Ultra Grey are all the same thing and will work great for sealing up a crankcase or cylinder base. Threebond 1211 can also be used, but its near 3X the cost and not really needed.

The other sealant type I've seen people use, and I'm not the most fond of it, is Permatex Anerobic Sealant. It hardens with the absence of air and is red sticky gelly stuff. I would stick with the semi-hardening threebond 1194.


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## mopar1rules (Nov 26, 2011)

Wicked500R said:


> What about the Threebond 1194 Northwood Saw sells? Is that the right stuff?



That will work perfect!!


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## Wicked500R (Nov 26, 2011)

mopar1rules said:


> That will work perfect!!




Ok, I will order it along with some other goodies. :msp_thumbsup: Thanks


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## southbound (Dec 4, 2011)

Anyone ever try the Permatex Ultra Grey???


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## Tree Wacker (Dec 4, 2011)

ol'homey said:


> Anyone tried good ol' Permatex 2B ? I've used it on a lot of things including in place of a base gasket on a couple of old Homies without any problems. It's fuel/oil resistant. I just put a thin coat on both surfaces, wait for a few minutes to let it get tacky and put 'er together. I know it's not as good as the stuff mentioned so far, but it is available at any parts store and it hasn't failed me yet.



i just used the Permatex 1 form a gasket sealant on my MS250 and it seems to work real good. i haven't had a problem out of it yet.Knock on wood


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## russhd1997 (Dec 4, 2011)

southbound said:


> Anyone ever try the Permatex Ultra Grey???



I used it to reseal the bottom of the crankcase on my MS180. I ran 5 tankfuls through it today with no problems.


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## fidiro (Dec 4, 2011)

From the Permatex line, the only one that I found to be gasoline proof and heat proof was the Permatex MotoSeal. I only was able to find the Ultra Grey locally so decided to get the MotoSeal instead that is labeled as gasoline and heat proof and odered it on Fleebay.

It's a grey sealant and was a bit watery when applied. You have to wait a bit before mating the jug to the bottom end and make sure not to put too much that it will bleed into the crankcase.


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## komatsuvarna (Dec 4, 2011)

southbound said:


> Anyone ever try the Permatex Ultra Grey???



Thats what I use. Some say not to, I know of several that do. Haven't had any problems *yet*.


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## diggers_dad (Dec 4, 2011)

mopar1rules said:


> That will work perfect!!



I had trouble with sealing a clamshell crankcase using RTV. I read this thread and ordered the Threebond that Northwood sells. It arrived lightning fast and I've already used it to seal two. Works great!! 

Thanks for the information!

Rep for mopar1rules!


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## FergusonTO35 (Jul 20, 2013)

I found this thread looking for info on what to use for sealing the bottom of the jug on my little Echo CS-3000. Nothing is mentioned in the parts schematic, gasket or sealer. What would you guys recommend for this purpose? I'm leaning towards Permatex Ultra Gray because I have used it so much on auto engines, but is there something better?


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## FergusonTO35 (Jul 21, 2013)

Thanks, I will for sure look for it.


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## Arrowhead (Jul 21, 2013)

I use Permatex Motoseal as well. I never had a problem with it and it's easy to work with.
I just used some on a CS-3000 a couple weeks ago. Sealing the jug. It looked like the factory stuff was some kind of shellac?? It was leaking terrible.


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## FergusonTO35 (Jul 24, 2013)

Arrowhead, I'm rebuilding my own CS-3000 right now and am deciding what sealant to use on the bottom of the jug. I'm wondering if anyone has ever used Permatex Form a Gasket #2? It is supposed to be highly fuel and heat resistant and non hardening. I've used it with success in many other applications but not a cylinder jug. I ask because I already have it at home, if #2 works just as well I'll just use that. Otherwise I'll go get the Motoseal.


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## Mike from Maine (Jul 24, 2013)

Anyone use permatex anerobic gasket maker?

I've got a tube hanging around... But I also ordered some threebond as well since everyone seems to like it.


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## Arrowhead (Jul 24, 2013)

FergusonTO35 said:


> Arrowhead, I'm rebuilding my own CS-3000 right now and am deciding what sealant to use on the bottom of the jug. I'm wondering if anyone has ever used Permatex Form a Gasket #2? It is supposed to be highly fuel and heat resistant and non hardening. I've used it with success in many other applications but not a cylinder jug. I ask because I already have it at home, if #2 works just as well I'll just use that. Otherwise I'll go get the Motoseal.



I've never used #2 on saws. I've used it a bunch on auto stuff though. I wouldn't take any chances, get either the motoseal, dirko, 3bond, yamabond etc... they are all proven winners.


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## FergusonTO35 (Jul 24, 2013)

That's what I figured, best to stick with what's proven. I'll pick up some Motoseal after work.

I did call Echo this morning and ask what they recommend. After some delay, the helpful (but not tech savvy) lady on the phone got ahold of a technician, who said that any automotive gasket maker product that resists gasoline should work and that there is no specific sealer listed in their data.


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## naturelover (Jul 24, 2013)

I've used #2 Permatex for a pan gasket on the 500, and as a gasket sealer on the head gasket of other stuff I've fixed. Also used it as a tank sealer on the Mac 10-10S. 

Seems to be working so far...

Will add the absolute worst stuff I've tried to get off is the Indian head gasket shellack. That stuff is horrible to remove. 


Sent from my iPhone 5 using Tapatalk


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## FergusonTO35 (Jul 24, 2013)

I've used a ton of #2 in auto and 4 cycle applications. It works great as both a gasket maker and a gasket treatment. Hi Tack gasket sealer is really good stuff too, especially for gaskets that need to be glued in place for correct assembly. Finally, Super 300 is a great gasket treatment that is my go to for most paper and cork gaskets. It can be applied alot more thinly with the brush top can and is not as gooey as the others.


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## barneyrb (Jul 24, 2013)

Mike from Maine said:


> Anyone use permatex anerobic gasket maker?
> 
> I've got a tube hanging around... But I also ordered some threebond as well since everyone seems to like it.



I tried it with poor results.....it never did "set" like I thought it should........


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## cowroy (Jul 24, 2013)

I agree with Barn^ I stick with motoseal every O'reilly's I have been in carry's it.


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## FergusonTO35 (Jul 24, 2013)

I sent Permatex an e-mail asking which product they recommend for sealing chainsaw jugs and crankcases and they quickly replied. Motoseal is what they recommend so I guess it's official now. Hopefully O'Reilly's has it in stock here also, Advance has to order it.


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## shorthunter (May 7, 2014)

Mike from Maine said:


> Anyone use permatex anerobic gasket maker?
> 
> I've got a tube hanging around... But I also ordered some threebond as well since everyone seems to like it.




I have used it on several saws. Works really well when mating aluminum to magnesium. I wouldn't try it on a plastic crankcase.


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## Hunowie (Jul 31, 2014)

So the only one that will seal plastic crankcase like husqvarna 235r is Permatex motoseal? Or others like permatex ultra grey would be enough?
Cause i used few others without luck.


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## nmurph (Jul 31, 2014)

Yamabond works fine.


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## rattler362 (Jul 31, 2014)

nmurph said:


> Yamabond works fine.


Neal have you tried yamabond5 yet?


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## fordf150 (Jul 31, 2014)

FergusonTO35 said:


> That's what I figured, best to stick with what's proven. I'll pick up some Motoseal after work.
> 
> I did call Echo this morning and ask what they recommend. After some delay, the helpful (but not tech savvy) lady on the phone got ahold of a technician, who said that any automotive gasket maker product that resists gasoline should work and that there is no specific sealer listed in their data.



Loctite 518 or equivalent. I have also seen them recommend Loctite 515


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## nmurph (Jul 31, 2014)

rattler362 said:


> Neal have you tried yamabond5 yet?



4 is designed for cylinder/case type applications.


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## woods works (Jul 31, 2014)

Another option that I haven't seen on a sealer thread is a contact cement type glue/sealer. I've used one that came from Tilton Eq. called Pliobond. It came in a 3oz glass bottle with a brush that made for easy application with no mess. Applied thin layer to both sides. Dries quick but stays pliable. Done a dozen or more cylinders with it with no signs of leakage (without gasket). It was time to re-order and found Tilton no longer carries it. Searched the net for Pliobond and found it on Amazon in an 8oz can w/brush vs 3oz glass for about same $$$. Should last me a few years!!


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## rattler362 (Jul 31, 2014)

The last couple saw's I have done I used Yamabond5 so far I like it.


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## a. palmer jr. (Jul 31, 2014)

I use Moto Seal that is sold at NAPA. My local store doesn't stock it but it's available on ebay..


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## Ifishsum (Aug 1, 2014)

Permatex MotoSeal here as well. Most other sealers don't say they are gasoline resistant, MotoSeal does. Most auto parts stores will have it.


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## a. palmer jr. (Aug 1, 2014)

Ifishsum said:


> Permatex MotoSeal here as well. Most other sealers don't say they are gasoline resistant, MotoSeal does. Most auto parts stores will have it.


 That's what I was talking about, they also use their own NAPA name Balkamp on it but I think it's made by Permatex.


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## blsnelling (Aug 1, 2014)

I use Loctite 518 most of the time. Also good are any of the products like MotoSeal, Threebond 1194, Yamabond......


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## Miles86 (Aug 1, 2014)

Howdy:

Hylomar Racing or Peramtex Motoseal grey or Yamabond 4

http://www.carid.com/permatex-autom...ket-dressing-and-flange-sealant-22885414.html


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## Mastermind (Aug 1, 2014)

I just smear it with Gary Goo......


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## mbret2004 (Jun 14, 2017)

Permatex Moto Seal will work well also.


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## a. palmer jr. (Jun 14, 2017)

Found out recently that Oreilly's auto parts carries the Motoseal.


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## cedarhollow (Apr 8, 2019)

reviving this thread
has anyone used omc gelseal witch i believe is 3m #847 comes in a red tube for sealing 2 stroke crankcase haves


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## Tooarbie (Sep 15, 2021)

Fish said:


> whatever.......
> 
> about any sealer will do....


Local chainsaw shop uses Fullaseal 700 Roof & Gutter - grey ... Has done for years and never had a problem! I note on their spec sheet that it is good to 150C, non-acetic and needs atmospheric H2O and 24hrs to cure.


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## a. palmer jr. (Sep 15, 2021)

If it means anything Dirko is about twice the price of Motoseal.


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## Vintage Engine Repairs (Sep 15, 2021)

a. palmer jr. said:


> If it means anything Dirko is about twice the price of Motoseal.


Dirko is expensive, though for the amount we need each tube goes a long way.


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## bwalker (Sep 16, 2021)

Yamabond, Hondabond or Threebond. All are good.
Don't use RTV. Gasoline dissolves it very easily and you will have an air leak sooner or latter.


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## Vintage Engine Repairs (Sep 16, 2021)

bwalker said:


> Yamabond, Hondabond or Threebond. All are good.
> Don't use RTV. Gasoline dissolves it very easily and you will have an air leak sooner or latter.


It doesn’t dissolve it as such. In fact gasoline dissolves the 3 you’ve mentioned. It will cause Dirko to swell and in thin areas shrivel.


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## bwalker (Sep 16, 2021)

Vintage Engine Repairs said:


> It doesn’t dissolve it as such. In fact gasoline dissolves the 3 you’ve mentioned. It will cause Dirko to swell and in thin areas shrivel.


The three I mentioned are made specifically for use on dirt bike center cases, which is nearly identical to a clam shell chainsaw. I have used Threebond and Yamabond many times and they have always worked perfectly.


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## Vintage Engine Repairs (Sep 16, 2021)

bwalker said:


> The three I mentioned are made specifically for use on dirt bike center cases, which is nearly identical to a clam shell chainsaw. I have used Threebond and Yamabond many times and they have always worked perfectly.


Yep agreed, but Dirko works perfectly too, Stihl has used it for decades even though it’s an RTV - which technically shouldn’t be used right? Just seems that any of the following work just fine even though none are fuel proof.


Silicone base sealers (remove
with fuel):


Dirko HT
Dirko Grey
Yamahabond 4
Pactan 6075
Permatex ultra black
Permatex the right stuff
Permatex ultra grey

chemical cure - (remove with acetone):

Hylomar universal blue
Yamahabond 1104 NEO Plus
Yamahabond 1194
Yamahabond 1184
Permatex Motoseal
Curil - T
Hondabond 4 ( TB1194)


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## bwalker (Sep 16, 2021)

To be clear you want to use Yamabond 4, or threebond 1194. I can't recall which hondabond product number.
Attached is the product data sheet for 1194. Note it says excellant resistance to gasoline. It is not a silicone product.


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## bwalker (Sep 16, 2021)

Vintage Engine Repairs said:


> Yep agreed, but Dirko works perfectly too, Stihl has used it for decades even though it’s an RTV - which technically shouldn’t be used right? Just seems that any of the following work just fine even though none are fuel proof.
> 
> 
> Silicone base sealers (remove
> ...


I can't comment on what Dirko is or isn't as I have never used it.
I do know that any silicone based product will not work very well and will eventually fail.


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## bwalker (Sep 16, 2021)

And Fwiw I believe that Threebond is the mfg for Yamaha, Honda and Kawasaki case sealants.


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## Vintage Engine Repairs (Sep 16, 2021)

bwalker said:


> I can't comment on what Dirko is or isn't as I have never used it.
> I do know that any silicone based product will not work very well and will eventually fail.


Yep, Dirko is a acetic cure silicone sealant. It has zero fuel resistant properties.


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## bwalker (Sep 16, 2021)

Vintage Engine Repairs said:


> Yep, Dirko is a acetic cure silicone sealant. It has zero fuel resistant properties.


I only bring up the silicone thing because I had a dirt bike that the precious owner used silicone to seal the joint between the intake boot and air box. Gasoline spit back caused the joint to fail and the motor sucked a bunch of sand though it. A cylinder replate, new crank assembly and piston latter and I was back in business, but a very expensive lesson learned. That sort of thing sticks in your mind!


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## Vintage Engine Repairs (Sep 16, 2021)

bwalker said:


> I only bring up the silicone thing because I had a dirt bike that the precious owner used silicone to seal the joint between the intake boot and air box. Gasoline spit back caused the joint to fail and the motor sucked a bunch of sand though it. A cylinder replate, new crank assembly and piston latter and I was back in business, but a very expensive lesson learned. That sort of thing sticks in your mind!


Totally get what you’re saying and totally agree!


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## a. palmer jr. (Sep 16, 2021)

Vintage Engine Repairs said:


> Dirko is expensive, though for the amount we need each tube goes a long way.


So does Motoseal.


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## TheTone (Sep 16, 2021)

Another vote for Yamabond 4. Tough as nails. A 3 oz. tube can be had on Amazon for $12 and change delivered and will do many saws.


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## Huskybill (Sep 16, 2021)

On Husqvarna dirtbikes where the pistons cost like a chainsaw I’ve tested pro seal engine high temp silicone on Husqvarna and suzuki bikes on the case seam.


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## Vintage Engine Repairs (Sep 16, 2021)




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## bwalker (Sep 17, 2021)

Vintage Engine Repairs said:


>



When there are products that don't do that I don't see the need nor the desire to use any silicone based sealant in a two stroke engine.


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## a. palmer jr. (Sep 17, 2021)

I'll say it again, best thing I've found is Permatex Motoseal, works, cheap, easy to find.


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## Vintage Engine Repairs (Sep 17, 2021)

bwalker said:


> When there are products that don't do that I don't see the need nor the desire to use any silicone based sealant in a two stroke engine.


Honestly, I have to agree. I like how easy it is to apply and it hasn’t let me down, but since seeing this thread and the other forum covering it all again, it makes me want to try motoseal once again. It just sets so quick that’s all.

Here in Aus where temps are warm all year round, you have literally 60 seconds to get parts together after it’s applied or it will have already skinned over then 24 hours to fully cure. Dirko takes about 10 minutes to skin over and then is ready to right away. No need to wait 24 hours. I guess that’s also why I have stuck wit it.


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## bwalker (Sep 17, 2021)

a. palmer jr. said:


> I'll say it again, best thing I've found is Permatex Motoseal, works, cheap, easy to find.


I've never used or heard of that particular product but just pulled up the data sheet. It appears it will work just fine and it's not silicone based.


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## Vintage Engine Repairs (Sep 17, 2021)

bwalker said:


> I've never used or heard of that particular project, but just pulled up the data sheet. It appears it will work just fine and it's not silicone based.


Yes that’s correct, motoseal is chemical cure, it’s essentially the same as 1184, 1194, 1104.


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## LoneOak (Sep 17, 2021)

Threebond 1184 or Dirko HT


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## Bwildered (Sep 18, 2021)

Try this stuff, it’s all I use now, from Diesel engines , tappet covers that should have cork to chainsaws, and not excessively hard to pry cases apart if used on


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