Author Topic: Intake manifold seals  (Read 2467 times)

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Offline JW113

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Intake manifold seals
« on: October 09, 2016, 10:56:07 AM »
Just a couple days ago when I was thinking to myself "gee, probably should strap that tool pouch to the frame"....

I was out doing a little test & tune yesterday, swang by the HD dealer for a oil pressure sender, the one on this bike seems to be flaky. It was running sweet out on the freeway, maybe 10 miles or so. I went to leave, and had a choice freeway or surface streets back to home, only about 3 miles, and deiced to swing my the auto parts store for some vacuum hose. Maybe a mile from the dealer, it started coughing and sputtering, and ultimately died. I pull over in the shade to have a look. Tried cranking a bit, would not fire, just spin. I start eyeballing it, and notice the carb is sitting kind of funny. Closer look reveals the manifold is not seated in the seals. No tools on my, I tried to wiggle it back into position, but only made it worse. Time to call the cavalry.

I give Roadrage Bob a call, he bops on over to the scene. Pretty clear the band clamps have to come off or at least completely released to get the manifold back in. After fussing a bit, we manage to get it clamped back in and head for home. What was observed was how soft and mushy these intake bands were. No wonder the carb fell off, but why then and there? Been riding a few weeks and no problem until now. So we head home, get about a half mile and it dies again. We pull over, and a quick diagnosis reveals it's out of gas! So I flip the reserve wing, and back in business.

So what I think happened, it ran out of fuel, started popping and backfiring, and blew the carb off from those soft gooey band seals. They came with the Cometic gasket set I had used, but apparently not good enough. These are just a plain rubber band, Bob said the ones he uses on his shovelhead are really firm, with threads in them like what's used in a radiator hose. These, when hot, seem to squish out from the band clamp.

So now need to find a better set of band seals. Any recommendations? I'm using those silicone type on my shovelhead, seem to be working fine so might give that a try.

I'm also now not thrilled with how the carb is supported only with that one strap from the tappet block to the air cleaner plate. That might support the weight of the carb, but also acts like a "hinge" and provides no support at all to hold the carb/manifold against the head ports. So yeah, a backfire along with slippery intake seals is going to blow the carb right off. Am thinking about adding another strap from the intake manifold to that bracket between the heads on the left side.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Offline garyajaz

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Re: Intake manifold seals
« Reply #1 on: October 09, 2016, 08:38:18 PM »
what kinda clamps ya got?

Offline JW113

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Re: Intake manifold seals
« Reply #2 on: October 09, 2016, 11:18:47 PM »
Aerospace style T clamps.
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Offline westcomb

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Re: Intake manifold seals
« Reply #3 on: October 10, 2016, 04:01:04 AM »
On my Shovels I just run the band seals that come with a James gasket set ............ I have never had a issue with them yet ........

Its not going to hurt adding another brace if you feel up to it also  :beer:

Offline Burnout

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Re: Intake manifold seals
« Reply #4 on: October 10, 2016, 07:26:32 AM »
What kind of additives are you putting in the gas tank?
They don't call me Ironhead Rick just because I'm "hard headed"

Offline JW113

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Re: Intake manifold seals
« Reply #5 on: October 10, 2016, 02:59:10 PM »
None.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Offline Burnout

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Re: Intake manifold seals
« Reply #6 on: October 10, 2016, 07:25:01 PM »
I asked because,

fuel with a high toluene content may soften rubber parts.
They don't call me Ironhead Rick just because I'm "hard headed"

Offline JW113

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Re: Intake manifold seals
« Reply #7 on: October 11, 2016, 08:52:32 AM »
Just plain old Chevron 91 octane. Trying to find some stock HD bands, but none to be had around here. Hate to mail order but that's where it is with old stock parts these days.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Offline garyajaz

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Re: Intake manifold seals
« Reply #8 on: October 11, 2016, 01:59:57 PM »
are yours the round 0 ring looking ones or the flat band ones?  I have several sets of both.
wont give ya the  0 ring ones I use now.
but the bands can be had from me for the shipping.

Offline JW113

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Re: Intake manifold seals
« Reply #9 on: October 11, 2016, 04:08:15 PM »
The band kind. Do you have the stock HD ones, or aftermarket? I have a few more aftermarket but am now leery of using them. I did order some silicon type, those seem to be working fine on my shovelhead.

thanks,
JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Offline garyajaz

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Re: Intake manifold seals
« Reply #10 on: October 12, 2016, 10:25:07 AM »
probably aftermarket.  but knowing my stock....very good ones.
they are pliable but very firm.
I bought two bags of 10 each. I change out each time when playing with carb/manifold stuff.
been running the stepped (0) ring type now many years.
the single support has held up dual throats, SU's , S&S L with added float bowl , all sorta stuff. its fine.
hell lots ran them with out the support bracket.

good fit and clamps are the key.
when folks started putting on round slide 38 micks they would backfire and blow whole carb off. was funny. did not take off manifold, just the rubber spigot mount. one hose clamp later and they running.

anyway, I thought you could not find any is why I offered.
when all  else fails with your stock feel free to let me know and I will send you mine.





Offline JW113

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Re: Intake manifold seals
« Reply #11 on: October 12, 2016, 07:25:19 PM »
Thanks Gary. What you have in the pics looks exactly what I have on there now. Am going to take another look at how the carb support bracket is fitted, maybe not supporting it correctly. But I was amazed indeed how soft and gushy those rubber band seals were when they got hot. Don't recall that before, which makes me leery of using another set just like them. It seems everybody and their Chow-chow are selling aftermarket band seals, for all I know sourcing from the same sweat shop in Shanghai. I have maybe three or four different ones on the way, will see how they compare. Including a set of silicone, I'm liking them on the shovelhead, no issues at all.

Here in one interesting thing I did see today though. Gates sells these "Power-Grip" hose clamps. They are basically like super heavy duty shrink tubing, they slip over the hose and tighten with heat, and continue to tighten over the life of the clamp. Used for radiator hoses, etc. Interesting concept, not sure I am ready to try that on an intake manifold, but hey, why not?

http://www.gates.com/products/automotive/passenger-car-and-light-truck/cooling-system/hose-clamps/powergrip-sb-clamps

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Offline garyajaz

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Re: Intake manifold seals
« Reply #12 on: October 13, 2016, 09:39:49 AM »
pix are not  showing now?
anyway I  have pictured two clamps. both different ones I tried. the one without slit in middle is the best type.
stock clamps not good for much.
those bands should not be gooy/soft. even under extreme heat which mine sees.
either way. if you have problem again just shout.
wont even charge ya shipping.

you are not hanging some 10 pound air cleaner off it are ya? some fake hypercharger junk?

but yeah your backfire out of gas probably did it.
keep the ol iron running!
also known is loosening up head bolts. there is a lot of bolt slop.
arraigning manifold centered. tighten up head bolts (new gaskets)
make sue gap is even. also insure the head shape matches the manifold shape. like non  o-ring head and o-ring intake.  seen it all...lol
on one stroker that leaked I tried both. had the 0-ring in slot, the band over o-ring.
still  problems.  he needed longer manifold cause of stroker plates.  .its doable.
or just,ah, keep gas in it.


Offline JW113

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Re: Intake manifold seals
« Reply #13 on: October 13, 2016, 07:48:03 PM »
From the vaults of the HTT document bin, HD Service Bulletin 788:

https://app.box.com/s/txwgveejqwy3uxzwl8x0307ccak6xsut

Interesting reading.

No heavy air cleaner, running S&S E and S&S air cleaner that came with it (for now). On the hunt for a Keihin CV...

Parts are tricking in, hopefully will be on the road this weekend. Barring rain, that is!

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Offline garyajaz

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Re: Intake manifold seals
« Reply #14 on: October 13, 2016, 08:08:10 PM »
I did not get the bulletin, but that is whats mentioned in my last post. tried all combinations.
with the stroker pistons and plates it now has I have a S&S matched manifold to head, stepped and longer-wider cause plates set intakes  higher.
fun stuff.

oh,  I have a perfect c.v. unmolested or drilled out or anything.  that S&S would look good on my sporty. had to take the ol fuel L series of.

Offline JW113

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Re: Intake manifold seals
« Reply #15 on: October 14, 2016, 08:30:32 AM »
Do tell! Are you saying what I think you're saying? Ping me if you are.
 :SM:

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Offline nibroc

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Re: Intake manifold seals
« Reply #16 on: October 14, 2016, 04:38:01 PM »
sounds like a trade---thought i had 1st dibs on it but had to get my GAL refurbished

Offline garyajaz

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Re: Intake manifold seals
« Reply #17 on: October 14, 2016, 05:40:42 PM »
yep, a trade sounds in order.

 
been riding hard (for me) all this week. sore daily. been 200 + mile daily loops around sate. building  up the for the 500 mile days.   (trip)
anyway, this weekend a couple party's  go to.
tomorrow some bictoberfest 100 miles round rip from here.
 bands and venders and usual  suspects. but it will be a good lunch ride.
gonna take suday of and check over/clean bike. 900 ,miles this week.   very few of these miles been freeway.
all mountain lane and some divided lane.  some long distance interstate should be easier.

  trying go get in shape for a ride  did 8 years and 4 surgeries ago..lol



so monday, yeah lets exchange some pix and stuff
« Last Edit: October 14, 2016, 05:51:58 PM by garyajaz »

Offline JW113

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Re: Intake manifold seals
« Reply #18 on: October 14, 2016, 06:41:44 PM »
 :up:

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Offline tommy g

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Re: Intake manifold seals
« Reply #19 on: October 14, 2016, 07:17:45 PM »
We got 6 inches a snow on the floor and you are workin up to a road trip. Something is wrong with my picture.
09 FLSTC
85 FXEF

Offline garyajaz

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Re: Intake manifold seals
« Reply #20 on: October 14, 2016, 08:01:07 PM »
well, I did wear a long sleeve t-shirt.
was 89 when left.  top of mountain was 78, then warmer down  other side of hill.
packed a sweat shirt, did not even think about it.
« Last Edit: October 14, 2016, 08:04:38 PM by garyajaz »

Offline garyajaz

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Re: Intake manifold seals
« Reply #21 on: October 23, 2016, 10:33:37 AM »
nibroc, I thought it was my L series you wanted??  (its still here)
oh well. that super E should do what sporty needs/ accel pump and enrichner
now if JW 113 would just take it off...lol

Offline JW113

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Re: Intake manifold seals
« Reply #22 on: October 24, 2016, 08:55:55 PM »
Gary, check your email. Pics and a request for ship to address.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Offline 72fl

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Re: Intake manifold seals
« Reply #23 on: October 25, 2016, 10:03:55 AM »
JW the Gates heat shrink, I know guys that are using it on Hot Rods for their clamps on all their Radiator hose and water pump connections work excellent and is a super clean application, have not used them myself but what I've heard :up:

Offline garyajaz

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Re: Intake manifold seals
« Reply #24 on: October 26, 2016, 05:24:14 PM »
just looked over hose/heat clamp site,
they mention works on all hoses.
ah, we have alum. and I thinking they designed to hold own weight and a hose.
not a carb and air cleaner. and vibration and other Harley stuff.
let me know if try and if work.

would have to cut them off to change something?