Experimental TEFLON Crankcase Seal / Nc250/Zs177mm

[Co2]

Loctite 518 is awesome solved material , thinner applicated yes this best, but 50 ml loctite 518 from here 50 dollares

[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.

[Weldangrind]

I'm with you on all of the Permatex silicone products, and each colour has a specific use. Black is resistant to gas and oil, red is for high heat applications, blue is safe for sensors and clear is good for glass. Grey is at another level, and I think it approaches aerospace grade.

All that said, I would not use silicone on the mating surfaces of two case halves. A superior flange sealant is your best bet.

[ripcuda]

I recommend ThreeBond 1211 and 1184. 1211 is more siliconey and caulk-like when applying. Still a little plyable when dry. 1184 is cheaper... grey... a tad more liquidy than 1211... easier to run a bead. 1184 is more hard when dry.

I've had great success using both on case halves and other metal-to-metal sealings on my 2-stroke and 4-stroke rebuilds. (jet ski recreational and racing engines)

Cheers!

[Co2]

Teflon band is OK ,

Warn : only if u cant found special locktite or another slicone/mastic gasket material, use that methode and applicate very thin job and master hand skill

im wait using period and tested any leak of oil, but it work no problem.