inlet nipple

[poorbiker]

While it would seem straight forward and in fact is, does anyone have some advice on how they have had successfully sealing nipple threads to head, other than the o-ring and some sealant on threads. I mention sealant because I did not use any. I discovered a nasty vacuum leak in one nipple, rear cycl. I installed both nipples after having heads redone, they were o-ring style. Threads are fine in head and there are no cracks around or in threaded hole in head. Ruined nipple extracting it, bummer cause it was oem, ordered new nipple but dont want a repeat. Yes im sure it was nipple to head leak, not manifold to nipple. Using peek seals. thnx

[Lonnie]

Perhaps he'll chime in but JIC he doesn't, Carl Olsen says he solves the problem by cleaning that area of the head 100% and uses JB Weld instead of a standard thread sealant to eliminate the leak(s). He has told me that it can't be done with the head on the bike because you can't get the head clean enough. The O-ring is a PIA, by the way.

[T. Cotten]

...I installed both nipples after having heads redone, they were o-ring style..... Using peek seals...

Poorbiker!

PEEK seals are for plumber's-style manifolds.
OEM nipples cannot be re-used anyway, as the rivet hole must be fresh.

Beware that one major USA producer of nipples put out a bad batch, and many may still be on distributor's shelves. Carl Olsen's will be correct.

Like Carl, I relied upon JBWeld for many years, and still do when the machine will not go directly into duty. My P4gas immersion tests showed it subject to degradation if not cured many weeks.
S&S Cycle is using Permatex's "The Right Stuff". Even though it states upon the can that it is not for use with fuels, my immersion test showed to to be un-fazed, and retained its pliability.

I have found no evidence that H-D used a sealer, however Indian did: (Attached).
Can anyone tell us what this compound was? Perhaps a "white lead"?

Thanks in advance,

....Cotten

[poorbiker]

Thnx as always Cotten,
You might not remember but I had posted a few months ago about an issue that turned out as you suggested was a vacuum leak, The heads had o-ring style nipples, removed them and installed an unused set of oem nipples I scored on years ago, they are still out there. And I to could never get a clear answer on any oem sealant that may have been used. I have had other knuckles but never had the need to replace nipples. I have thought about using loctite red, I know its more for fastening, keeping things in place, but I have had good luck over the years sealing everything from hydraulics to head bolts to you name it. I think loctite makes a sealant? I know guys are using something just trying to get a consensus,

[poorbiker]

Cotten, do you have a part number for Carls inserts for FL. Was going to use Colony`s...............

[T. Cotten]

Cotten, do you have a part number for Carls inserts for FL. Was going to use Colony`s...............

Poorbiker!

You need a phone number, which I keep at the shop.
Google: Carl's Cycle Supply.

No saccharin-based Loctite survives modern fuels.
As I mentioned, there is no evidence of an OEM sealant, although I look forward to any at all.

Did you rivet the nipples?

.....Cotten

[poorbiker]

no I used a fastener, stainless steel with a lock nut on outside, the screw is kinda like an elevator bolt so there is little protrusion in intake track of nipple, actually sealed with some Permatex 59235 high temperature thread sealant I had. Probably will use that on inserts. I see no need for using rivets unless bike is getting judged or your a stickler for such things.

[T. Cotten]

Poorbiker!

I am a stickler for rivets because when properly installed, they do not rely upon a sealer, and preserve the History, along with the value of the hardware.

Judging is for speculators and the vain.

....Cotten

[poorbiker]

I get that, pretty sure you wouldn't like my scoot then, lol. Thnx Cotten for the info.

[T. Cotten]

You judge me harshly, Poorbiker!

I would have nothing against a farmer's old nail for a rivet,
as long as it stayed sealed.

And I don't even like my own bikes.

....Cotten

[poorbiker]

I guess its like cooking, taste better when someone else has made it. I have never been completly happy with anything I made or built, no judgment brother if everyone liked shania twain I would then rather ride rosie odonell, the end.

[T. Cotten]

Wow you lost me there, Poorbiker,...

But please alert us all if the Permatex sealant ever fails;
Its not about the sealer, they are all great, its about the P4gas.

You never know what will come out of the next pump.

.....Cotten

[poorbiker]

Cotten or anyone
,I am now officially frustrated, I did find vacuum leak, I installed new inlet nipples from Carls, I used the permatex high temp sealant, reinstalled manifold, made a block off plate as Cotten suggested, hook up line and regulated air in to about 15 psi, sprayed everything with soapy water, valves closed, absolutely no leaks. Rechecked float and adjustment, was ok, generally disassembled carb and checked all vent holes, passage ways, everything I could. Re-installed carb, set initial adjustments, bike fired up no problem, warmed engine reset low speed and went for ride, exact same issue, throttles up great, idles great, re-starts hot or warm great, however, while holding steady throttle in any gear engine seems lugish, exactly like when your in to high a gear when slowing, sputters, slight roll on throttle and no issue, acceleration no issue, recheck valve adjustment next morning, perfect. Plenty of power. Stock cubic inch, stock comp. m74, morris G5 magneto. I dont know where to go from here, keep thinking its carb related but now, well now I need some input, not my first knuckle but first with a linkert, heeeeeeeelp, want to ride.

[T. Cotten]

Poorbiker!

You have made important and serious progress to cure that leak.
Now let us proceed further.

Did you grind both the manifold and carb flanges flat before assembly?
They are almost always distorted from fastener stress, as the extremely-malleable '49 manifold shows in the attachment. The idle gallery upon the carb body stiffens its flange, and telegraphs a similar distortion to the manifold: Like if you place your hands together in a praying position, and then relax your knuckles outward, away from each other.

The manifold to carb interface is not bubble-testable, but an un-lit propane torch might give an indication of a leak while the motor is running.
And you can also snoop around the throttle bushings with it.If that first diagnostic produces no effect, then we shall address the rest of the carb, since we must assume the mag, timing, valves, etc. are all in order.

Your float is at ¼", but does it really float?
Its not brass, or a california nitrophyll boatanchor, is it?

Had to ask before we go on to other things,
We are here for you,

....Cotten

[poorbiker]

Hey Cotten,
Did not check carb mount flange or manifold mount flange, will do that tomorrow,
Yes foam float from "into the wilderness" I believe it floats, lol.
Throttle bushing, hmmm, have convinced myself that even if it had a small leak it shouldnt have that much affect, however, it is a little suspect just by feel. Will check that also.
I am determined to make this carb setup work, I have an o-ring manifold and s&s carb. sitting around just in case, but no inlets. thnx Cotten will check those out.....