Triple screw tappet cover gasket in a pinch?

1980 Special Twin

XS650 Enthusiast
Messages
67
Reaction score
187
Points
33
Location
Pittsburgh, PA
CONFESSION: I have never checked my valve clearance. It's one of the last items of routine maintenance that i've neglected all these years and that day has come.
There is plenty of info on the job so it should be easy. I popped the covers and so far so good.
But I noticed PO used red rtv on the valve covers. Everyone here seems to think that isn't good. Gonna order the paper gaskets (my homemade gaskets always suck, must have missed that day of kindergarten) but i am curious what would happen if a gasket cover failed? Be it the PO's rtv or my mangled paper gasket?
 
It'd leak. Not too many things easier than cutting a tappet cover gasket, even just using a cereal box for the gasket paper.
True. Must be one of the more easier gaskets to make yourself, I go to ebay and buy summat like this

https://www.ebay.co.uk/itm/224082996479?hash=item342c632cff:g:VNMAAOSwJZNfEHq0

Must be similar on US ebay? Oh, and I use leather punches to make the screw holes

https://www.ebay.co.uk/itm/15499285...CDbY50WkI4S2ICZvivV5bBdTMnud|tkp:BFBM5t7hvfBg
 
Yep, I have lots of hole punches. I still have an almost complete set I bought in 1976 (made in the good old US of A, if memory serves), very good quality, unfortunately, you can't buy them anymore so I can't replace the bits I've lost over the last 46 years.
 
OR, go to a real auto parts store and take a cover. Have them fit some o’rings for you. A NAPA might do it.
Somewhere on here, the size is listed. Order a bunch of them and adjust your valves as a routine task.
 
Your siggy says 1980; Those valve covers use o-rings, with fresh o-rings ZERO sealer is needed, no doubt a good fresh silicone o-ring is the ideal way to seal the valve covers. 70-to 75? used gaskets and IMO thicker is better cuz the cover seals against the joint where head and cam cover meet, often that joint isn't perfectly aligned.
 
From the great o-ring, seal thread, found in tech....
1664370482475.png
 
Yes indeed has o-rings! Not sure why previous owner used rtv. Could be shot, i will have to check. Maybe he didn't know where to find the great o-ring, seal thread!
The McMaster-Car o-rings listed are a bit thick. If you just run the crown nuts to snug, they're great. I'm nut positive you can't pull a stud if you try to crank them all the way down.
 
Be especially careful with the lower stud on the RH front cover. That stud is short in the head and is known to pull out.
What @jetmechmarty sez, the covers do NOT need to touch the head, just SNUG the nuts evenly going around all three a couple times, don't crank em down.
Silicone is highly preferred to Buna N it's softer and works/lasts great in this use.
The orings are bit tight to push into the cover groove, lube em a bit with sil-glyde or such, push into the groove at 3 or 4 different spots then finish, if you start pushing from just one spot you will find you have "extra" when you get all the way around. ;)
 
Last edited:
I'm nut positive you can't pull a stud if you try to crank them all the way down.
Yep, you sure can. The problem is those nuts might have been reefed on dozens of times before you ever saw the bike. Eventually the threads will throw up their hands and surrender. This one gave up before it even got to "snug."
Helicoils are one the greatest inventions of our time.


1664470732394.png


1664470761782.png
 
The P.O. of my '83 put gaskets on, along with lots of sealer, but some still leaked badly, lol .....

$200Special5.jpg


A thorough cleaning and new silicone o-rings sealed things up nicely .....

$200SpecialClean3.jpg


Yes, the 3mm diameter replacements we use are slightly larger than the 2.8mm diameter originals but they fit fine and are easy to find. That 2.8mm original size is sort of an oddball.
 
orings 010.JPG

First time installing, a couple times later (valve adjusting) they'll pretty much touch. Check the flange on the inside of the covers, the factory often left drips of clear, razor blade em off.
 
But I noticed PO used red rtv on the valve covers. Everyone here seems to think that isn't good.

Yeah, it's a PO thing.....I've seen RTV used on various things for years where there was no need. I think a lot of DIY'ers are convinced it the thing to do:
20210316_004351.jpg
20210316_005845.jpg

20210316_015355 (2).jpg

IT'S NOT!
 
this engine is a battle of bolt holes stripping vs oil leaking that takes napoleon level strategy to win
 
Back
Top