Reply To: Using Anaerobic sealer

[Don]

Spaghetti seal crankcase flanges require the type M/847 sealer to be used. In reality, you shouldn’t really need any sealer on spaghetti seal flanges, the spaghetti seal does all the sealing. The type M is used to help glue the spaghetti seal in place so it won’t fall out of the grooves during crankcase assembly. You surely don’t need to use much of the sealer, just enough to glue it in place securely. The anerobic sealer will not set up with air present, so it will be useless in terms of gluing the spaghetti seals in place.
Sealing crankcases properly can not be over emphasized, it is often seen as a minor chore with little significance. Spaghetti seal and type M/847 are used together…Anerobic sealers are only to be used on flat crankcase flanges with no grooves/spaghetti seal.
The benefit of the type M/847 is that it sets up quickly and strong. This benefit is also one of its detriments, because parts have to be assembled quickly, before the sealer hardens, or the crankcase halves will not mate and seal properly.
The anerobic sealers are nice to use because they don’t set up quickly, until the crankcase halves are reassembled and the air is removed. The downside of the anerobic sealers is the prep, which is critical…Improper surface prep will result in poor sealer performance, aka crankcase leaks. Something as innocent as greasy fingers while applying the anerobic sealer might be all it takes to keep the sealer from setting up properly.