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Bigraz

Question on moly lube for vale adjustment

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I am going to do my first valve adjustment on my 450 but my dealer can't find the moly lube that Yamaha says to use in the service manual.Is there anything else that i can use for the cams+shims to properly lube it?Thanks.

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Just use the oil you are going to run in the engine. Soak down the cams before you place the caps back on and then again before you put the cover back on and you should be fine. It's not like you are going to be breaking in new cams or anything. Hope this helps.

Josh

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The shims and valve stems are the only parts that moly is called for. The reason for this is that molybdenum provides a barrier type lubricant that adheres to the small craters in the metal surfaces that will protect when a fluid film(oil) type lube fails.

Many folks will make the mistake of adding lots of moly rich lube to these parts when servicing, and that can be a mistake. Molybdenum disulfide (MoS2) can help to cause a wetclutch to slip if there is very much MoS2 that gets mixed in with the engine oil.

Yes, many engine oils...even MA rated moto specific type oils, will contain moly, but it will be a different moly compound than MoS2.

What you could do is use a moly dry-film type chain lube, or a moly rich grease.

But, do not simply slother it on. We are talking microscopic when we talk barrier type lubricants, so you would only need to put some of this type of lube on and wipe it immediately off. It may seem that you have defeated the purpose by wiping it off, but trust me, the moly is polar and will have adhered to the places you want it.

There are also rebuild fluids that contain other types of barrier lubricants. These types of lubes will do the very same job as moly, and in many cases a far better job. But these types of fluids will not effect the wet clutch operation even when massive amounts are seen. Using one of these type of rebuild fluids lets you use one single product for all of your parts coating during rebuild. These fluid perform FAR past what a thin coat of any engine oil can.

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You could use STP, but I don't recommend it, even in small quantities. There is really no need to use anything other than your engine oil, which is a very high quality oil (it is, isn't it?), and is all that will be on those parts eventually in any case. The stems, shims, and the button on the underside of the bucket are the least of your worries. Far more critical is the bucket (tappet, lifter) bore, the cam journals (where they ride in the head) and the lobes.

If you feel compelled to use an moly bearing assembly lube, you can get it at any auto parts house. But bear the point about using an excess in mind. It only takes a small dab to do the job of putting a film between the two parts. There may very well be as much moly in a 1 inch bead of many assembly lubes as there is in two quarts of some engine oils.

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STP is calcium and ZDDP...why would you not want to use it even in small amounts?

Are we to add these items to the same dealerspeak scare that moly ladened engine oil enjoys now?

The "reason" that moly is called for is the barrier lubricating properties, that such minute amounts of engine oil simply do not provide.

And engine oil running over a part that has had a polar solid applied will not simply "wash" it off. The molecular stuctures of the barrier lubricants adhere themselves to the asperities of the metal surfaces.

The molybdenum compound that is in engine oil is different from the molybdenum used in rebuild fluids, gear lubes, chain lubes, and greases.

And I agree that the journal bearing surfaces and the cam lobes are far more critical than the shims, and that is exactly why a rebuild fluid that contains a barrier additive should be used. And as this application concerns the wetclutch as well, a moly rich fluid should probably not be used.

HotCams also prescribes exactly what I do, and for the same reasons.

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STP is calcium and ZDDP...why would you not want to use it even in small amounts?
Fair question, and the answer is that it contains more than that. But the calcium that it contains in such high concentrations can find its way into the carbon deposits of the combustion chamber, where it can create hot spots and contribute to preignition. Other metallic boundary lubricants do not cause this particular problem. Used only as an assembly lube, it probably won't be a problem, but then what happens to the rest of the can? You shouldn't dump the stuff in anything, IMO.
Are we to add these items to the same dealerspeak scare that moly ladened engine oil enjoys now?

The molybdenum compound that is in engine oil is different from the molybdenum used in rebuild fluids, gear lubes, chain lubes, and greases.

My sensors detect a personal attack. I'm shocked. But you confuse me with someone else. I have raised the point on several occasions that moly compounds per se are not a sign that an oil shouldn't be used around a wet clutch. In fact, I've pointed out that almost all of the very best JASO MA oils contain moly. Some have quite a little bit of it. And I am aware that Molybdenum disulfide (MoS2), a friction modifier, is not typically used in engine oils, at least not those that do not carry the "energy conserving" badge. The moly in most good oils is usually Molybdenum DialkyldiThioCarbamate (MoDTC), or Molybdenum di(2-ethylhexl) phosphorodithiolate, both of which are more a boundary lubricant by nature than a friction modifier. In fact, Mobil 1's MX4T motorcycle oil contains more MoDTC than their car oil does. You must have been thinking of someone else.
The "reason" that moly is called for is the barrier lubricating properties, that such minute amounts of engine oil simply do not provide.
The ZDDP you mentioned is a barrier (boundary) additive, and is among the most common used in any engine oil. When an oil film is present, the parts are hydrodynamically lubricated, and barrier lubes are good insurance, but not in play. Furthermore, the Zinc, Phosphorus and Moly boundary lubes in the oil that was run in the engine throughout its life up to the point of the valve adjustment in question will already be worked into the parts involved, just in case they're needed. If you don't give a second thought to starting your bike after it sits for two or three weeks, why would you worry about using engine oil as a prelube?
And engine oil running over a part that has had a polar solid applied will not simply "wash" it off. The molecular stuctures of the barrier lubricants adhere themselves to the asperities of the metal surfaces.
In the small quantities that you and I both recommended, that's true, at least to the extent that the asperities (the porous irregularities that exist at a microscopic level on all wear surfaces) are not already filled with other boundary lubes from the engine oil the parts have been lubed by all their lives. But oil will wash away the excesses we both recommended against, and the moly compounds found in most assembly lubes, greases and chain lubes are MoS2, more often than not.
And I agree that the journal bearing surfaces and the cam lobes are far more critical than the shims, and that is exactly why a rebuild fluid that contains a barrier additive should be used. And as this application concerns the wetclutch as well, a moly rich fluid should probably not be used.

HotCams also prescribes exactly what I do, and for the same reasons.

Again, it is a film of engine oil, together with whatever buildup of barrier lubricants exists, that protects the very same parts on every cold start, and even against the effrontery of being started with a dry oil tank and an empty oil filter , as happens after an oil change on later models. Hot cams recommends a moly assembly lube for new cams, and that makes much more sense, and is much more necessary, because any new parts will not have been subjected to the pre-treatment that the used parts have received from their engine oil. In that case, you should use assembly lubes, prudently.

It's my position that in the case presented by the OP, you can use moly lube, but that it isn't necessary unless there are new parts involved, and if used, care needs to be exercised. And that's all I have to say about it. But I can't quite get whether you are saying to use the moly compound or not use it. You've said both in this thread.

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Fair question, and the answer is that it contains more than that. But the calcium that it contains in such high concentrations can find its way into the carbon deposits of the combustion chamber, where it can create hot spots and contribute to preignition. Other metallic boundary lubricants do not cause this particular problem. Used only as an assembly lube, it probably won't be a problem, but then what happens to the rest of the can? You shouldn't dump the stuff in anything, IMO.
What is in STP that would be detrimental when used as an assembly lube? Calcium is not a metallic boundary lubricant, and is most often used as a dispersant/detergent to help keep carbon off of parts. However in certain circumstances it can serve as a barrier additive. I would be interested to see your source on the warning you give about carbon deposits in the combustion chamber.

And what happens to the rest of the can would be to put it on the shelf. Who suggested dumping their assembly lube anywhere?

No, STP will not hurt one thing at all by using it as an assembly lube in the place where the manual calls for moly fluid. We are talking less than one cc here.

My sensors detect a personal attack.
Don't know where your senses got that from. I only mention dealerspeak type comments because the myth surrounding moly and EC rated engine oils is for the most part unfounded, and it seemed you were starting another myth concerning ZDDP and calcium use in engine oil...which is unfounded as well.

Maybe you can tell us what eles is in STP, as you state that there are components other than ZDDP and calcium...and elude to them being detrimental?

The moly in most good oils is usually Molybdenum DialkyldiThioCarbamate (MoDTC), or Molybdenum di(2-ethylhexl) phosphorodithiolate, both of which are more a boundary lubricant by nature than a friction modifier.
Glad to see that you have been doing a little reading...

Both are friction modifiers and both are boundary lubricants. Simply because the terminology used by dealerspeak marketeers will claim "no friction modifiers" when the fact that moly...in any form...is present (amoung other FM's), does not change things. They only claim this because of the myths that surround EC oils and moly. They are incorrect, and you can't change science just becuase of the marketing speil that gets thrown around.

Moly, in any form, is used primarily as a FM additive.

The ZDDP you mentioned is a barrier (boundary) additive, and is among the most common used in any engine oil. When an oil film is present, the parts are hydrodynamically lubricated, and barrier lubes are good insurance, but not in play.
I've noted from some of your previous stuff that you have this train of thought, but it is not correct. Boundary lubrication is in play each and every time we start our engines. And it is also in play during much of the run of a high performance engine. I suspect you got your thought process from seeing verbiage that describes boundary type lubricants as a last resort only when the fluid film fails..etc. But, the fluid film is violated on a regular and consistant basis. That is a fact.

Science and facts trump dealspeak mumbo jumbo each and every time.

Furthermore, the Zinc, Phosphorus and Moly boundary lubes in the oil that was run in the engine throughout its life up to the point of the valve adjustment in question will already be worked into the parts involved, just in case they're needed. If you don't give a second thought to starting your bike after it sits for two or three weeks, why would you worry about using engine oil as a prelube?
Again you make assumptions you can't back up. Also, if we are doing a sevicing of the valves, would it not be possible that we are adding new components that have not seen engine oil yet? I do give start-ups a second thought, as I know for a fact that them most wear occurs during this period. But it is just a fact that we must start the engine. I do not worry about using engine oil as a prelube, I just know that there are better fluids available that will do the job much better.
Hot cams recommends a moly assembly lube for new cams, and that makes much more sense, and is much more necessary, because any new parts will not have been subjected to the pre-treatment that the used parts have received from their engine oil. In that case, you should use assembly lubes, prudently.
Not so...HotCams warns against using moly prelubes on new cams that are placed in service with a wetclutch. And all assembly lubes are to be used to simply coat the parts with a thin film...and again we aren't talking about dumping the lube into the oil sump. (Note that I suggested wiping off a moly rich assembly lube after application.) I can only assume that HotCams forsees people making a bonehead move and dumping a moly rich assembly fluid into the sump.
It's my position that in the case presented by the OP, you can use moly lube, but that it isn't necessary unless there are new parts involved, and if used, care needs to be exercised. And that's all I have to say about it. But I can't quite get whether you are saying to use the moly compound or not use it. You've said both in this thread.
My position is that moly lubes can be used where prescribed by the Yamaha manual, and furthermore I suggested that if they are used, they be used predently, and even wiping the excess off before assembly. If the mans valves were in spec, he wouldn't be adding new shims now would he?

I also content that there are better fluids to use that contain chemo-absorbable components that are far better performers than moly, that can be used throughout the rebuild or servicing process without worry...even if they get dumped into the oil sump, be it on purpose or on accident.

I think that you chimed in to show your superiority on the topic, as you are seen by many as the king of all things moto...but to me it only opens you up to the things that you have yet to learn about tribology. I could see you correcting me if I gave bad advice, but I did not give bad advice.

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