seeking advice
seeking advice
I currently have the cylinders off my 1978 R100/7. I am waiting for the heads to return from a rebuild. I have had the cylinders off before and this time I hope to do a better job. There never was (as far as I know) an o-ring where the cylinder meets the block. Last time I used Hylomar? sealent where the o-ring would be. No problems, had oil to the rocker arms, no leaks but a slight weep at the block cylinder junction. Can I get some advice on the proper way to use this sealent? How thick? Maybe thicker away from the oil passages? I would love a picture of this sealent applied properly. Can I but the cylinders back on without the heads to hold the sealent in place till it cures. Thanks in advance for any help.
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John Falconer
- Posts: 78
- Joined: Tue Aug 03, 2010 11:34 am
Re: seeking advice
Don't use Hylomar - it won't seal perfectly and is no longer recommended by BMW.
A VERY thin coat of Hi-Temp silicone sealant (I like the orange-colored stuff from Permatex) will work but you do need to be judicious in your application. Cleanliness is key - clean the mating surfaces thoroughly. I then lay on a narrow bead of sealant and smooth it out to be VERY thin with a popsicle stick (thanks Don!). If some gets into the recesses for the small o-rings, clean it out before assembly.
A VERY thin coat of Hi-Temp silicone sealant (I like the orange-colored stuff from Permatex) will work but you do need to be judicious in your application. Cleanliness is key - clean the mating surfaces thoroughly. I then lay on a narrow bead of sealant and smooth it out to be VERY thin with a popsicle stick (thanks Don!). If some gets into the recesses for the small o-rings, clean it out before assembly.
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Kurt in S.A.
- Posts: 1657
- Joined: Tue Aug 03, 2010 12:08 pm
Re: seeking advice
The only visual that I've seen is on this website.
http://www.gunsmoke.com/motorcycling/r1 ... index.html
Kurt in S.A.
http://www.gunsmoke.com/motorcycling/r1 ... index.html
Kurt in S.A.
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Dave Backmarker
- Posts: 58
- Joined: Tue Aug 03, 2010 1:16 pm
Re: seeking advice
Michael,
I'd suggest you purchase a copy of Oak's Boxer Top End Disassembly-Reassembly. Oak may be contacted at askoak@aol.com. Oak's manual has many, many invaluable tips and techniques.
In the manual, Oak describes how you want just the thinnest coat of the sealant as described above. Hylomar should also be allowed to set for a few minutes and then securing the heads to the block allows the entire assembly to be squeezed while the sealant cures. Given that, my recommendation would be wait until you get your heads back before you reinstall the cylinders.
DaveM
1975 R90S, 2000 R1100RT
I'd suggest you purchase a copy of Oak's Boxer Top End Disassembly-Reassembly. Oak may be contacted at askoak@aol.com. Oak's manual has many, many invaluable tips and techniques.
In the manual, Oak describes how you want just the thinnest coat of the sealant as described above. Hylomar should also be allowed to set for a few minutes and then securing the heads to the block allows the entire assembly to be squeezed while the sealant cures. Given that, my recommendation would be wait until you get your heads back before you reinstall the cylinders.
DaveM
1975 R90S, 2000 R1100RT