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Best Shovelhead rocker gaskets?

21K views 17 replies 11 participants last post by  shovithead 
#1 ·
The rocker boxes on my Shovel leak like a sieve. I'm currently using the James steel gaskets, and like a moron I didn't put any sealer on them. So, they leak...alot... I don't need a whole top end gasket set this time, so I'll just order gaskets individually. That leaves me wondering, who makes the best Shovel rocker gaskets, and what type of sealer should I use on them? Thanks for the info.
 
#2 ·
I've always had good luck with the steel James gaskets, I run them without a sealant. I've also used the blue paper S&S gaskets with no problems too. Anyones gasket should work. I would check the bottoms of the rocker boxes themselves for "trueness". A sheet of 600 grit sandpaper and a piece of glass can go a long way towards "flattening" the box's gasket surface. TK.
 
#3 ·
I re-flattened the bottoms of the boxes with some glass and sandpaper while it was apart. I'm not talkin some weeping, I've got a full on quart every 100 miles leak from both rocker boxes. You'd think there was no gasket in there at all. Do the heads themselves ever warp?
 
#5 ·
Don't have the name of the vendor, but a few months back, I had a shovel that did the same thing. So I took a chance on ebay, with a vendor who sells his own brand of custom made gaskets. Aluminum center with some kind of carbon covering. They seal up like none I have ever used. Do a search on ebay for "the best shovelhead gaskets ever" and you should be able to find them. He will "sell now" and the price is not as bad as you would think, on ebay. Checking flatness is necessary too. But, once, when doing a shovel motor, I had a bad leak on the rear head, turned out, the rocker stud had backed out, just slightly, to where the larger lower threads were out of the head, not allowing the rocker to completely seat on the head. May not be it, but worth checking. If the stud shows the larger thread, sticking out of the rocker mating surface, then you need to tighten, and reassemble. Crank pressure can affect this too, so make sure you have all the oil lines correct and that the vent is "breathing".
 
#7 ·
While your at it: that is taking the rocker covers off and checking the head flatness which means you should really remove the studs. Make sure your 1/4" studs are not stripped out. The torque specs on the rocker cover bolts is something around 15 to 17 ft*lbs (from memory) and I know from experience if you torque them to 20, the studs will strip out as they are threaded into the aluminum heads. You may have some stripped studs requiring a heli-coil. I'll beg to ask the question: What's the best way to seal the ends of the rocker shafts where they get nutted on the left side of the rocker box. That's where mine always seem to weep......
 
#8 ·
What's the best way to seal the ends of the rocker shafts where they get nutted on the left side of the rocker box. That's where mine always seem to weep......
I make sure the bore in the rocker box at the plug end is polished smooth and has no chrome or powder coat or paint or gouges. . .

And use an o-ring that is fat enough to bear against the shaft and the box. Never leak a drop when done this way.

The white square seals also work nicely when you are unable to do the above. I find that they take a set though and don't last as long as the o-rings.

Jason
 
#11 · (Edited)
I had the same problem until I used the white polymer looking Rocker plug seals which when torqued will form fit the shaft hole against the box & plug to form a leak free fit ( J&P Part # 7400272 ) $9.99 for a four pack:D And on the left side I used Pipe Sealant with PTFE from General Motors Part#12346004 ~ Highly recommend this shit for a thread sealant , used it alot while wrenching at the Dealership. Kind of pricey thou $25.00 for a tube of 1.69 FL.OZ.(50ml) but really really good!
 
#10 ·
As far as the head, I'm with Creepinogie. Even if you lap the rocker boxes, your heads may not be flat on the tops. You could have gouges, warpage or even puckers around the stud holes themselves. Pull the studs, remove the valves/springs/retainers and lap those surfaces as well.
 
#13 ·
I have 2 Shovels, one with the alum and silicone (?) coating and one with gray paper using Hylomar as a sealant.

The paper with Hylomar does NOT leak.

The aluminum with silicone or rubber that cost about $20, leak like a sumbitch.

Both bikes were checked for flatness and studs by the same guy...me.

Hylomar will contour to low spots and nicks and seal them up. Unless of course it is very bad.

Never more than 15 ft. lbs. on the nuts, JMO.
 
#14 ·
Laugh if you want, but if you have a persistant leak, and want to seal it up, go to the yamaha shop and buy a tube of Yamabond. You can install your rockers with NO gaskets and they won't leak. That crap is expensive too, but it is the best sealant I have ever used, and I swear by "made in the USA", but they got this shit right.
 
#16 ·
Laugh if you want, but if you have a persistant leak, and want to seal it up, go to the yamaha shop and buy a tube of Yamabond. You can install your rockers with NO gaskets and they won't leak. That crap is expensive too, but it is the best sealant I have ever used, and I swear by "made in the USA", but they got this shit right.
gotta agree with this old codger on this one. been using this shit since I was 13 riding MX and jet ski's. I know some HD guys that will ONLY use yamabond to assemble cases. sometimes i'll use a paper gasket and a thin coat of yamabond on the head and rocker box to fill in any imperfections. I have also used that brown tar aviation gasket sealer with good results. I think permatex makes it now and calls it indian Head Gasket Shellac, and it comes in a small brown container. Again, I'll coat both metal surfaces with a thin coat and use a paper gasket. also, I clean everything with laquer thinner before final assy to make sure no oil or residue is left on the parts. one more thing to remember is that equal consistant torque is more effective than overtightening.
 
#17 ·
Thanks all for the input. I originally had it apart to replace a blown head gasket. Did both while I was at it. Before I took it apart, it had a very slight weep at the rocker boxes, after reassembly, it leaked like a sieve. I'll check everything over really well when I get it apart.
 
#18 ·
Hey Chad, I am NOT a old codger, I am a young codger. :rolleyes:
 
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