clamshell case sealant thread

[cookies]

In the OE repair manual it states dirko ht but as everyone knows over time new things are invented and products are improved as well as the availability of certain things may not be the same in one place but available elsewhere not to mention the extra cost to order/ship specific things. dirko or the new sealant requires a lengthy trip to a stihl dealer then pay their large markup, the same can be said for any re labeled sealants IE hondabond, yamabond, ford fluid etc etc. Permatex products in my experience work excellent for its specific designated purpose if you use the right ones for their specific purposes. My question is using one of the permatex products to seal block to cylinders, specifically this one due to local availability at half the price. Permatex 27037 Optimum Black Gasket Maker Feel free to weigh in your own opinions/experience..would prefer something easily obtained but if it's necessary to pay 2-3 x more to do it right the first time that's what I will do

 

[CausticUC]

That specifically is an RTV for different material types and oil resistance. Guessing it is for valve covers, maybe manifolds.

Have never used it myself, doesn't really fit any of my applications that I dont have something else for.

 

[cookies]

oil , vibration temperature resistance and availability locally are what got my attention

 

[SimonHS]

There was some great information in this previous thread:

https://www.arboristsite.com/community/threads/yamabond-4-or-5.343843/

 

[cranman1951]

I've only used PermatexBlack but after I started the previous thread, bought some YamaBond 4 to try out.....I'm going to try it out tomorrow putting in a popup piston in my Husky 350 project with gasket delete....BTW, my Stihl Dealer mechanic recommends Permatex Black....

 

[old guy]

I've been using permatex ultra grey & ultra red with no problems.

 

[Vintage Engine Repairs]

I have tried a few types and did a full circle back to Dirko. Just buy a tube and forget about it remember to stick some petroleum jelly / vaseline in the cap before screwing it back on once you’ve finished, then squeeze out some dirko and dispose of it next time you use it. Stops it setting up in the tube.

 

[Clyde85]

I have put two saw's together with permetex moto seal so far so good. But I haven't much time on mine and neither has my dad with the other. One is a 350 Husqvarna and the other was a cs 2150 Jred.

 

[CausticUC]

Okay, since we went this way again....
I use a J-spec grey motocross racing silicone, however for a gasket delete I use the Permatex Aviation Gasket Maker.

 

[huskihl]

I have put two saw's together with permetex moto seal so far so good. But I haven't much time on mine and neither has my dad with the other. One is a 350 Husqvarna and the other was a cs 2150 Jred.

Motoseal works well

 

[Clyde85]

Actually I have used it on three saws. I done a 520sp Jred as well.

 

[SteveSr]

In the OE repair manual it states dirko ht but as everyone knows over time new things are invented and products are improved as well as the availability of certain things may not be the same in one place but available elsewhere not to mention the extra cost to order/ship specific things. dirko or the new sealant requires a lengthy trip to a stihl dealer then pay their large markup, the same can be said for any re labeled sealants IE hondabond, yamabond, ford fluid etc etc. Permatex products in my experience work excellent for its specific designated purpose if you use the right ones for their specific purposes. My question is using one of the permatex products to seal block to cylinders, specifically this one due to local availability at half the price. Permatex 27037 Optimum Black Gasket Maker Feel free to weigh in your own opinions/experience..would prefer something easily obtained but if it's necessary to pay 2-3 x more to do it right the first time that's what I will do

What you need is a high temperature silicone that will actually harden (set) that is rated for filling gaps... like where the bearing and case halves meet. Personally, I use Dirko HT after having issues with others that don't meet the above specs.

 

[jellyroll]

motoseal is what i use and recommend

 

[Clyde85]

I used the motoseal because it is fuel resistant. Silicone sealants are not.

 

[SteveSr]

I used the motoseal because it is fuel resistant. Silicone sealants are not.

Motoseal is not rated for gap fillling. It also won't fully cure in 24 hours. Try pressure testing your next clam shell 24 hours after assembly and see what happens...

 

[Vintage Engine Repairs]

Motoseal is not rated for gap fillling. It also won't fully cure in 24 hours. Try pressure testing your next clam shell 24 hours after assembly and see what happens...

Steve you know the mission I went on with sealers, I found the same thing, moto seal won’t fill any slight gaps and I pressure tested a clammy and it just leaked. Right back to Dirko and that settled it for me. I also concluded that Dirko exceeds the necessary resistance to gas. I actually put 3 small holes in a metal gas can and plugged each with a different sealant - moto seal, three bond and Dirko. Dirko is still holding to this day after the other two dissolved after about 24 hours. It seems when it is between / in a gap or between halves it holds solid, but if you put it on a surface and submerge or get gas on it it wrinkles up.

 

[Clyde85]

I guess I will have to keep this in mind then for future reference. I have yet to see dirko for sale around here. That's why I used motoseal.

 

[sundance]

Looks like there are a number of Dirko's. Which one should I use to redo an MS250?

 

[SteveSr]

Looks like there are a number of Dirko's. Which one should I use to redo an MS250?

Dirko HT (red).

 

[SteveSr]

I guess I will have to keep this in mind then for future reference. I have yet to see dirko for sale around here. That's why I used motoseal.

Dirko HT is still available online. Stihl has recently switched (or maybe switched back) to some gray material. If you order the Dirko from a Stihl dealer, at least in the U.S., you'll get the new gray stuff.