Experimental TEFLON Crankcase Seal / Nc250/Zs177mm

[jimjr21]

I have never seen teflon tape used in this capacity in over 30 years of engine rebuilding.

Personally I use Wurth brand Flange Sealant Green. It was developed for Rolls Royce aircraft engines to seal machined surfaces.

I most commonly see engines with Yamabond or Hondabond sealing them. Again products designed to properly seal an internal combustion engine coming in contact with oil, fuel, coolant, etc.

I will be looking to see your results. I hope they are positive.

I worry that the tape rolled will have too much thickness and distort the machined tolerances and alignment.

[SpudRider]

Originally Posted by jimjr21

I have never seen teflon tape used in this capacity in over 30 years of engine rebuilding.

Personally I use Wurth brand Flange Sealant Green. It was developed for Rolls Royce aircraft engines to seal machined surfaces.

I most commonly see engines with Yamabond or Hondabond sealing them. Again products designed to properly seal an internal combustion engine coming in contact with oil, fuel, coolant, etc.

I will be looking to see your results. I hope they are positive.

I worry that the tape rolled will have too much thickness and distort the machined tolerances and alignment.

Jim,

Can you recommend any of the Permatex gasket makers?

http://www.permatex.com/products-2/p.../gasket-makers

[jimjr21]

Originally Posted by SpudRider

Jim,

Can you recommend any of the Permatex gasket makers?

http://www.permatex.com/products-2/p.../gasket-makers

Any of those products will work to seal the crankcase.

As others pointed out the gray is a good all around choice.

[Mudflap]

My favorite is Loctite 518 or whatever Permatex calls it nowadays. I used it for years on motorcycle crankcases, Rotax aircraft engines, washing machine transmissions, and everything else that did not need the spacing of a paper gasket.

[Weldangrind]

Originally Posted by Mudflap

My favorite is Loctite 518 or whatever Permatex calls it nowadays. I used it for years on motorcycle crankcases, Rotax aircraft engines, washing machine transmissions, and everything else that did not need the spacing of a paper gasket.

X2.

I've had similar results with Three Bond. I would not use silicone.

[SpudRider]

Originally Posted by Weldangrind

X2.

I've had similar results with Three Bond. I would not use silicone.

Did you use Three Bond 1104, 1211, or another product?

http://kzrider.com/archive/viewthread.php?tid=18859

Seriously, I have had very good results using Permatex Ultra Black. It was recommended to me by my good friend Andy, who is a professional diesel mechanic with over thirty years of experience.

My Honda XR650L has a steel gasket for the valve cover. We commonly reuse this steel gasket, since it is not deformed during installation. When I did a top end rebuild of my Honda XR650L engine, I applied a thin coat of the Permatex Ultra Black to the steel gasket, and it did a very good job.

Also, the oil sight glass in the engine of my Zongshen Sierra 200 became loose after 50,000 miles or so. This engine is virtually identical to the engine in the Yamaha TW200 motorcycles. The oil sight glass is surrounded by a rubber grommet, and is held in place in the right crankcase cover by friction. My friend Andy recommended I seal it in place with Permatex Ultra Black. I followed his advice, and the repair is still in excellent shape after 20,000 miles.

I just talked with my friend Andy, and asked him a few questions. Andy likes the high oil resistance of Permatex Ultra Black. He has used this sealant at work for many years. However, he stresses it is vital to clean the mating metal surfaces with brake cleaner, to remove all traces of engine oil. If any engine oil remains in the pores of the metal, the seal will leak. However, cleaning the metal with brake cleaner, et cetera, allows the sealant to enter the pores of the metal and make an excellent bond.

Andy used Permatex Ultra Black at his old workplace for many years. At his new workplace they use Permatex Ultra Grey. These sealants are not deteriorated by engine oil, which can dissolve some other sealants, and send chunks of material into the bearings, destroying them.

[SpudRider]

Originally Posted by Weldangrind

I've used Three Bond and Loctite 518 with good results.

Originally Posted by Mudflap

My favorite is Loctite 518 or whatever Permatex calls it nowadays. I used it for years on motorcycle crankcases, Rotax aircraft engines, washing machine transmissions, and everything else that did not need the spacing of a paper gasket.

We have two respectable votes for Loctite 518.

http://www.loctite.co.uk/loctite-408...=8802626633729

[Co2]

Originally Posted by jimjr21

I have never seen teflon tape used in this capacity in over 30 years of engine rebuilding.

Personally I use Wurth brand Flange Sealant Green. It was developed for Rolls Royce aircraft engines to seal machined surfaces.

I most commonly see engines with Yamabond or Hondabond sealing them. Again products designed to properly seal an internal combustion engine coming in contact with oil, fuel, coolant, etc.

I will be looking to see your results. I hope they are positive.

I worry that the tape rolled will have too much thickness and distort the machined tolerances and alignment.

Amazing experience sir , i'm just trust crankcase in surfaces layers very sharpness and flat build , and first time demntage crankccase seeing original seal remainder has very thick.

Photos first try's , latest version better visual and reasuring ,smooth.

İhope to, that methode succes... if failed 4. time demontaged moto block