Hi,

I have taken out the valves from my GK73A and I have read that on replacement they need some Moly Paste applying to the stems of the valves, is this correct?

If so, I have looked around for some paste with no luck.. Do you guys use a paste when re-fitting the valves? if so, what paste? Is there an alternative to moly paste?


Thanks,

Steve

You sure it is not moly grease?

If nothing else available, I would use engine oil mixed with some molybdenum grease.

If no grease, some oil would do, just don't scratch the stems or the seals with anything.

Have you lapped them in already?

CMSMJ1 wrote:You sure it is not moly grease?

If nothing else available, I would use engine oil mixed with some molybdenum grease.

If no grease, some oil would do, just don't scratch the stems or the seals with anything.

Have you lapped them in already?

The workshop manual said Moly Paste.

I have lapped them in already, yes.

Cheers. Any further info and clarification would be great. :)

Well.. the Honda manuals I have state that you make a 50/50 mix of oil an molybdenum sulphide grease to use when installing the valve gear and cams etc.

I assume this is the same stuff and that paste is a translation error/issue.

Hi, I tookthis from a manual I have (the manual is for the GK71B however).

Here it says Molly Paste and also inside my manual for my Suzuki GSX750F it also suggests Molly Paste.

Would the alternative you suggest be fine? As I see it mentions the same molybdenum. I have no clue, so it is safer for me to ask :)

Cheers.

I reckon it is the same deal. The Honda books say to use the 50/50 stuff as I mentioned before.

You won't go far wrong with making the same paste up from new oil and molybdenum grease.

The paste is probably something that Suzuki sells...

Moly paste and molybdenum fortified grease are very different things, moly grease is about 5/10% moly but the paste is 50/60% usually stated i.e moly50. Its a thick paste type lube that will not run off with heat and is available in small tubes. Should be put on the part of the valve stem thats inside the guide.
If you google moly paste you should find it easy to get hold of at about £5 a pot, think the stuff ive got is Honda.

Hi Callist I'm doing the same job on my 76A, can I ask how much play if any you have on the valves when in the guides? as I've got a tiny amount on mine and not sure if this is ok.
I rebuilt my fzr engine a few years ago and didn't use any kind of moly on it with no problems. I think if you are using the old valves & guides (matched) it's not such a worry as they are already worn to each other.
Dobbs.

Hi dobbslc, This is the first bike I am rebuilding so I dont want to give any false information as I am learning :) However, when placing the valves back in I didnt specificly check for play so I cant entirely remember. I do remember the valves went through the guides with a tight fit while being slid through however.

I hope you get it sorted and it all goes smooth for you.