In the last 3-4 years I have seen more broken oil filter housings (cracked, right thru the bolt hole) than in the previous 30 years. I started wondering if there was some 'life limit' to the aluminum, until it dawned on me that the year of the engine involved didn't match up with a chronology.
Then someone e-mailed me about his that just broke, during which he mentioned that his Clymer manual called for "19-24 ft-lbs torque" for this bolt (!!!!). That then rang a bell (like it was filled with concrete): Clymer typo'd away a decimal point in those numbers! The figure of 1.9-2.4 ft-lbs is much closer to what this should be reading, and I'd bet lunch that 24 ft-lbs will make short work of one of these filter housings.
Heck, even the head nuts on the 750 don't take that much torque! Don't do that...
Honda is once again offering the 'real' O-ring for these housings, too. It is a custom part in these bikes. The ones that come with EMGO or Tourmaster filters are NOT the correct ones, as they are much too skinny to seal. The cross-section of the correct one is 4.5mm, as in Honda part
O-RING (89X4.5) 91316-425-003
and this nice, thick one will last about 10 years under normal use. It just takes snugging down of the big bolt to make them seal (2 of them if you are using the F2/3 "tweener" oil cooler plate).
I just switched mine out (from 1980) to a new one, I think it was finally time...
