Can I reuse half moons on valve cover?

[Elysium]

Pulled the valve cover since the gasket was shot. ordered a new one from real gaskets. Getting the old one off is alot of work. Tried to keep the big chunks out of the cams but if some small debris gets in the oil it should all get filtered out right?

Can I reuse the half moons? they look ok and the seaping that I was getting was not coming from the cam covers.

Also the breather cover gasket was really gummy. Kinda like fudge or putty. Scraped it all off. Got a new Real gasket for that too. Do I just keep the metal oil screens in there or should they be replaced? Do I have to coat them with anything? They look a bit rusty.

Going to check clearance of the cams while in there too.

Thanks

[MisterCinders]

What kind of bike?

The half-moons should be reusable. Better to wipe out any debris with a rag than to rely on the filter. You don't want any bits to interfere with the cam/shim gaps.

You should also change the oil while you're in there.

[cowboyup3371]

You can but be careful you put some sealant under the half moon itself (NOT THE GASKET) to help seal it in. I didn't and mine are leaking again from the front left. Do a search through the archives though to make sure.

[Redman]

Ely,

Welcome to GSR.

Not necessary to replace the half moons. BUt do check to see that they are somewhat soft yet.
Let me ask you this: would you describe them as being rubber or plastic ?
They are suppose to be rubber, if they seem more like plastics (as they seem to get after aging and being hot so much), well, then maybe they will not seal up too well.

I would invite you to introduce yourself in the "owners" section.
Pictures, we all like pictures of bike.

Also a good idea to state your bike model/year in posting. MAybe put in signature line so shows up on every posting (Goto UserCP).
Depending on your specific model, some folks may have a comment for you about the Real Gasket.
ANd regardless of the model, let me state some unasked-for-advise, beyound the scope of your question, and point out that the torque specs for the cam cover bolts for the Real Gasket are in INCH-pounds (not foot pounds).

.



.

[hampshirehog]

Hi and welcome to the funny farm.

You can reuse the half moons. Most people put a smear of gasket sealant on them before popping them back (just a smear - nothing more). Sometimes I do and sometimes I don't - I've only had one leak once and even then I just pushed the thing back in and it was fine.

What bike have you got? List it in your sig then everyone will know all the time. If you have got the tach gear in the cam cover the real gasket is a bad idea as the gear doesn't mesh nicely with the exhaust cam drive and one ot the other will get boogered.

Do you're best to get that gasket material out. You want to make the risk of blocking an oil way as low as possible and some of the holes are pretty small.

A breakfast cereal gasket will do for the breather cover. No need to pull that cover very often so as cheap as you can works fine. As for that mesh in there just give it a rinse in white spirit or the like to clean it up, dry it out and put it back in - there's no need to renew it.

[Elysium]

Thanks everyone for the quick replies.

Yeah year and model would help huh? Whoops! (77 GS750) The half moons do seem more rubber then hard plastic. I was planning on just leaving them in since thats not were the seaping was coming from. Don't have to pull the cams, everything is within clearance. I was going to do my best to get all the gasket junk out of the oil. Oh and the tach goes in at the top of the head, but I don't recall a gear in there, only the ones for the cam chain. Already ordered the real gasket so will have to see how it works.

[1980GS1000E]

Touchy thing about the Realgasket is tightening torque. Be careful and don't over tighten the bolts. The gasket is rubber and these bikes were designed with fiber gaskets which can take and require a lot more pressure to seal.

[rapidray]

Touchy thing about the Realgasket is tightening torque. Be careful and don't over tighten the bolts. The gasket is rubber and these bikes were designed with fiber gaskets which can take and require a lot more pressure to seal.

Do not EVER use a "Real Gasket" on an engine that has the tach drive gear in the valve cover!!!!! EVER!!!!! Ray.

[Suzuki_Don]

The '77 GS750 motor DOES NOT have the tacho drive in the valve cover, the tacho drive is in the cylinder head. So a Real Gasket would be OK in this situation.

[Elysium]

Thanks. I'll be sure to torque properly. Yeah it looks like the only gear is on the cam itself for the tach. I'm glad to know it will work.

[hikermikem]

Don't have to pull the cams, everything is within clearance.

Welcome...

Don't know your level of experience with maintaining these old bikes, but you don't have to pull the cams to adjust valve clearances...

Those 8 valve engines use shims to set the gaps under the cam lobes; please make sure you have checked/adjusted the gaps correctly or you can risk burnt valves.

Sorry if this is info you already know, but your previous statement indicated that perhaps you weren't familiar with how to properly adjust the valves:

http://members.dslextreme.com/users/bikecliff/images/gs850valve_adjust.pdf

Mike

[Elysium]

no ive never really done any valve adjustments. I did replace a cam chain on an old honda once. I looked over the suzuki manual and saw that you can pull the shims out with a special tool and not have to remove the cams.

I was just saying I was just going to leave the half moons in. I would imagine they have to come out if you pull the cam?

[nufnuf]

you cannot rely on the filtering system in the engine filtering small peices of gasket. Use every precaution to keep from dropping junk and gunk and old gaskets and silicone sealant etc etc into tour crankcase. There are too many critical oil passageways that are easily blocked and can cause terminal pain.
So get use to spending hour upon hour prepping gasket surfaces carefully.
It is possible to use the cable tie method to swap shims. (*****NEVER turn the engine over without a shim in )Use a coin or something if you havent got a spare shim Dont run the bike with a coin as a shim replacement. You need to check your clearances
Dont use oil with friction modifiers, it will wreck your clutch.
After you get it all back together and run it and it purrs like a kitten because you did everyhing and got it all right the first time change the oil
If those mesh thingys in the breather cover are rusty and falling to bits. throw them away as you dont want rusty metal crap through your engine
Half moons are reusable you have to clean them and glue them in

[1980GS1000E]

you cannot rely on the filtering system in the engine filtering small peices of gasket. Use every precaution to keep from dropping junk and gunk and old gaskets and silicone sealant etc etc into tour crankcase. There are too many critical oil passageways that are easily blocked and can cause terminal pain.
So get use to spending hour upon hour prepping gasket surfaces carefully.
It is possible to use the cable tie method to swap shims. (*****NEVER turn the engine over without a shim in )Use a coin or something if you havent got a spare shim Dont run the bike with a coin as a shim replacement. You need to check your clearances
Dont use oil with friction modifiers, it will wreck your clutch.
After you get it all back together and run it and it purrs like a kitten because you did everyhing and got it all right the first time change the oil
If those mesh thingys in the breather cover are rusty and falling to bits. throw them away as you dont want rusty metal crap through your engine
Half moons are reusable you have to clean them and glue them in

Couple of things I may disagree on here. The oil filter is designed to catch stuff like pieces of gasket and dirt particles. If some falls down the cam chain tunnel, it will go to the sump and then be sucked up through the screen if it isn't blocked at that point. Then the pump and filter. If the filter is not damaged and installed correctly, then only oil will be pumped through the motor and maybe minute specks of dirt that will have no negative effect on the engine anyway. I would go ahead and change the oil and filter anyway.
I would never use a coin as a substitute for a shim, even if it's just to rotate the engine over enough to swap a shim. Get a spare shim.
Also, if you remove the mesh, it should be replaced.