moly assm. lube DANGEROUS?

Should I really use this stuff on my cam lobes when I adjust? I can remember hearing something about this stuff ruining a new engine (automotive) when used to assemble it and then left in. I used this stuff (bel ray) when I did my valves and now I wish I had not. All that metal in there can´t be a good idea on a high reving engine like this. I´ve changed the oil once since I used it, I can still see the coloration of it in the oil.... :):):D Anyone know if this stuff is really all that much of a good idea? How important is it to flush out after first run?



As long as you don't slop it on all willy-nilly and change your oil after running a couple of hours I wouldn't worry about it at all. It's good stuff, the factory uses it.

No need to use it to check and adjust valve clearances. In the old days we just put a dab of heavy grease that would disolve with the oil. :)

All that metal in there can´t be a good idea on a high reving engine like this

What do you mean by that? What does "that metal in there" have to do with the assembly lube? :)

It clogs the oil filter, just change the filter after 20-30 minutes of running...

Quoted material:

What do you mean by that? What does "that metal in there" have to do with the assembly lube?


Well, MOLY.. is short for molybdenum which is a metalic element... hence metal. I know that if you put this stuff in the wrong place it will kill things over time. I know a HP automotive machinist that told me NEVER to assemble and engine with that stuff. Slipped my mind when I was shopping and Bellray on the label.

I think I´m going to go chance my oil again. Now I´m pissed.


My bro gave me a good idea when I was putting a new cam in a bike. STP engine treatment. It's thick enough to stay in place when first starting and breaks down in the oil very well. Just put a little on the dry part your putting in, ie a new cam.

Yah, my Grampy was a Cat and heavy equip mechanic and he swore by Power Punch for engine assembly, practically put it on his corn flakes. This is a really super gloopy STP´ish sort of thing, Napa carries it. They also carry a MOLY powerpunch formula for differentials which he did not use.


can someone clarify for me? by moly grease do you mean molybdenum disulphide based stuff or something else?

moly-disulphide based grease is like the chucky cheese of greases, hence the question

yeah MattyH thats the one. I'm the HAZMAT guy for my unit (USAF) and i agree that moly-b is really good stuff. It is one of the main lube requirments for the WR's.

I agree Moly based grease is the be all, do all for grease (except for sealing air filters)...however, it's NOT appropriate for cam lobes or other engine parts on your WR. As the WR shares oil between the engine and the clutch/transmission, and moybdenum disulfide is both super slippery and super penetrating (both good features of a grease), it will cause your clutch to slip like dog shit on a dance floor. STP or other non-moly based assembly lube is appropriate for engine assembly, including installing new cams, but not necessary for adjusting the valves. (oh, by the way, says so in the owner's manual)

should not be a problem, how much did you use a pint ?. :D

This is what I used when I did my valves the first time. I put a light coating on the cams, shims and buckets. I had absolutely no issues. You're using such a negligible amount that it hurts nothing. Friction modifiers like molybdenum become an issue when they're a major ingredient in your primary lubrication medium, i.e. engine oil. Granted, the oil reaches the valve/cam area, but it's not going to do anything to your clutch, crank, etc. Besides, if you're changing your oil regularly, then you've got nothing to fuel your paranoia anyway...SC

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