Board index Flathead Power-Technical Questions, Answers, and Suggestions Knuckles intake leaks

intake leaks

Post Thu May 06, 2010 6:58 am

Posts: 251
Location: Hudson, Florida
I asked this question last nite but it seems to have disappeared:) A friend has brought over a set of Knuckleheads, it has o-ring seals and he wants to go back to plumbers style. In the past I have sealed them up with a Teflon pipe paste I got from a mold shop I worked in,I can,t find the tube to give you the name but I'm still looking. My question is, do the S&S heads still use the threaded inserts and what do they use if so?

Post Thu May 06, 2010 7:24 am

Posts: 732
Location: nekoosa,wisconsin,usa

S&S (Flathead Power ) Knuckleheads use Pan style o-ring intakes nipples

Post Thu May 06, 2010 8:49 am

Posts: 251
Location: Hudson, Florida
Thanks John, are they removable like the old heads? or machined as part of the head? If removable, what does S&S recommend to seal the threads?

Post Thu May 06, 2010 5:52 pm

Posts: 3160
Location: Central Illinois, USA

No matter what sealer is chosen, the next formulation of pump gas doesn't care if it eats it.

To the best of my research, H-D used no sealers and depended entirely upon mechanical seal.

Indian used an unidentified nipple compound, perhaps white lead.

We are all in the same boat.


Post Thu May 06, 2010 9:49 pm

Posts: 251
Location: Hudson, Florida
I guess we'll seal it up best we can and re-do it when needed. If things keep on like this we won't be able to ride them much longer anyway. Our fearless leaders will have us all on one of these ... device.htm Kind of reminds me of the video with the missing motorcycles:)

Post Sun May 09, 2010 6:48 am

Posts: 251
Location: Hudson, Florida
Interesting that you've found no sealer on the threads, I wonder if the second part of my replacement does more for sealing than the Teflon Shop Dope. I have allways finished the repairs with a generous dose of engine heat paint, After starting the machine and allowing a short warm up I recheck the headbolts and reapply another coating of paint by brush. Rewarm again and apply a third brushed on coat of paint. It may be that the paint is doing most of the sealing:) The two brushed on applications are applied to the threaded areas only.

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