Gasket sealer on head covers?

[luvmy40]

So, I got the new head cover gaskets and carb parts in the mail today But I'm not allowed to open them till Christmas:(. Listen, that's the deal I made and I'll hold up my end of bargain! That didn't stop me from pulling the necessary plastics, yanking the carbs and getting the head cover bolts loosened up this evening.

 

My question is this: Does anyone find it necessary to use a gasket sealer on the head cover gaskets? I have always used HiTack to "glue" the gasket to to the cover for ease of installation but I've never used anything between the gasket and the head on any of my bikes.

 

The reason I'm replacing the gaskets is because the new(chicom) gaskets I installed last winter after doing the valve adjustments have leaked horrendously from day one. I went through nearly 2 gallons of oil this summer. The new gaskets from Partzilla are OEM, Yamaha gaskets. Can I expect them to seal up without any help? The 30+ year old gaskets I tore off last winter did not leak at all.

[Yammer Dan]

A touch to hold them in place shouldn't hurt anything.

[Flyinfool]

Even with the chicom gaskets I would think that you probably either rolled one or it slipped out of the groove and got pinched. No amount of sealer will help if you roll or pinch a gasket. I do not use sealer other than a few dabs of black RTV to help hold the gasket into the cover during install, install while still wet.

[luvmy40]

I've inspected thoroughly. neither gasket is rolled/pinched and both leak from the Ds and nearly every where else. Either the gaskets are too thin or my new cushions are. I'm hoping it's the gaskets.

[gaj1917]

I've used Permatex High Tack Gasket Sealant. Wonderful stuff. Just to be safe, I add it throughout the entire valve cover groove. If nothing else, that lessens the likelihood of a gasket rollover on install. Mighty tight quarters if you're doing this with the engine in the frame.[h=1][/h]

[bongobobny]

One of the biggest issues with valve cover leakage is NOT replacing the rubber gaskets on the valve cover screws! What happens is those rubber "O" ring pieces are compressed, and the screws holding the valve cover down bottom out before the gaskets have a chance to seal!! You definitely need to replace those round rubber pieces when replacing the valve cover gaskets...

[luvmy40]

I put new bolt cushions on last spring. They shouldn't need replaced again. I've reused the Yamaha head cover bolt cushions for many years on other models.

[bongobobny]

OK, after one year it would seem that they shouldn't have taken a "set" but you never know. Myself, having come from the aircraft industry, we would never reuse an O ring when rebuilding something even if it was only a couple of months old as compression plus heat equals deformation.

 

I was just throwing that out as it is a fairly common cause for head gaskets to leak when they are replaced. The compound of the bolt cushions stay in the compressed state having taken a set, so the bolts are allowed to go in further without giving any kind of downward force on the valve cover, and the bolts themselves will bottom out and you think they are tightening down the valve cover but they are not. IMHO it is kind of a bad design that allows this to happen but who am I to challenge some Japanese Engineer...

[luvmy40]

I'm considering stacking a 1mm thick silicone washer under the bolt cushion just for insurance.

[Condor]

I've never had need to do this but others have. Place a washer between the valve cover seal and the head of the bolt. Since the bolt is shouldered it will only go so far before bottoming out. The washer will give a little more pressure against the cover and keep an old gasket from leaking. Should work on a new set of gaskets too. Did you know that the 2ndGen OEM valve cover gaskets work better then the 1stGen OEMs....??

[luvmy40]

I thought they were just easier to install due to an extra sprue that helps keep them in place.

 

 

 

I did talk to my local Yamaha shop(great bunch of guys who actually love the old bikes) and they told me they have an after market bolt cushion that works well and is 1/3 the price of OEM. If she leaks again with the OEM gaskets and chicom cushions, I'll try their after market suggestion.

[Condor]

I thought they were just easier to install due to an extra sprue that helps keep them in place.

 

 

 

 

I did talk to my local Yamaha shop(great bunch of guys who actually love the old bikes) and they told me they have an after market bolt cushion that works well and is 1/3 the price of OEM. If she leaks again with the OEM gaskets and chicom cushions, I'll try their after market suggestion.

 

I thought that's what 'works better' might mean??

 

Washers are .15¢ at your local Ace Hardware....

[luvmy40]

OK, I'd say "easier" but I getchya'.

 

The chicom gaskets went down fine, no pinching or rolling. They're perfectly flat and in place. They just leak from everywhere. Literally every inch seeps oil and it's the worst around the cam cut out Ds. They are are just too thin. Either that or the chicom bolt rubbers are not to spec. Or a combination of both.

 

Either way, I'll get her sealed up this winter. I'm sick of adding oil every other day and putting down dry sweep on the driveway!

[luvmy40]

After comparing the new OEM gaskets to the 1 year old chicom gaskets, there is no doubt whatsoever that the chicom gaskets are the reason for my leakage! The OEM gaskets are nearly twice as thick as the cheapo gaskets and ribbed differently. I am confident that the new gaskets will solve my weeping head cover problem.

[WildBill1]

The new OEM gaskets being thicker is probably the answer. If not I've used Loctite 518 on trail bikes covers, cases and Harley's both cases and covers solving leaks.