SU carburetor and intake questions

[js73shovel]

Hey guys,
I was riding the other day and noticed a leak in either my intake or carburetor. I felt the intake manifold was really loose so I pulled it off and saw the exhaust clamp rubber was torn and the intake manifold gasket (which looks more like a spacer to me) was pretty scratched up. I tried just refitting the 'spacers' I had but one fit and stayed perfectly and one did not fit because it was warped slightly so I went to the harley dealership thinking I could grab a couple new clamps and manifold spacers but the guy at harley said it wasn't a spacer just an old hardened o-ring and just gave me some intake manifold o-rings for a 1973 FLH. I tried installing it with the o-ring i got from harley but it seems impossible to align the intake manifold with the exhaust clamp rubber around it? I have an SU carburetor and a 1973 shovelhead. Anybody know where I can get these spacers or the correct gasket for the intake manifold and any suggestions on best way to install it?

[rockman96]

Those look like 'rubber band' intake seals, not spacers... They were used on later model shovel intakes. If you have a '73, and it has stock heads and the correct SU manifold, you should be using the o-rings alone. If you have mismatched ports and intake, someone probably used the rubber bands to try to make it work. Either one is a bitch to put on, just be patient with it until you figure it out. It works best if you afix the intake and seals, and then put the (open ended) clamps on over it and cinch it down.

[js73shovel]

it would be a lot easier if I didn’t use the exhaust clamp rubber. Would it seal the intake with just the o-ring if it were ‘73 ports?

[JBinNC]

If the intake manifold has a lip to accept the oring, like the head does, and the lips are not broken, the oring is preferred BY FAR over the later flat band seals. The orings are foolproof, but can be a bother to install by yourself. If you decide to use the orings alone, you will need oring size clamps, the band style clamps are too big to be used with orings.
I emphasize again, the orings are far better than the band seals and if you have the right parts, in good shape, orings are what you should use.

Now, the hard plastic rings you found under the bands are non-stock adapter rings to allow the use of bands and/ or a band type manifold on an oring head. They just take up the space around the oring lip when a band is used.

A pic or two of your heads and intake manifold would be helpful.

Jim

[Dragstews]

Those hard plastic thin rings are for filling the gaps where the O-Rings sit ..
They are used with the later (78-up) band type clamps ...

[js73shovel]

Here are the heads and the manifold

[AbbandonZK]

Mixed manifolds. Late band style cylinder heads with a early o ring manifold. In order to continue running he carb you will need a band style intake manifold or get a late style super e manifold for bands and use a conversion manifold.

https://riveraprimo.us/products/1133-0039?_pos=34&_sid=362526805&_ss=r

[JBinNC]

Well, you do have an oring style manifold, but the heads are band style (late '78(?) to '84). So you will have to buy and install new bands. Forget the orings. If you can fit the adapter rings, fine, but if they are warped, you can just leave them out.
The band kit drag shows above is certainly the business, but a pair of stock bands carefully installed with good clamps should do fine.

With band type seals, you MUST use a good carb support bracket (or two) to keep the carb and intake from wiggling around and destroying the bands, which from your pictures looks like what happened.

Jim

[js73shovel]

Damn! so with this adapter I would get a band style manifold and add this adapter to the manifold then the carb? Damn that carburetor will be sticking out like an added 3-4", yeah?

[JBinNC]

No! Use the manifold you have. If you can fit the little adapter rings, good, if not, skip them. You need two rubber band seals, 27062-78 (?) and maybe two new clamps if yours are iffy. No need to reinvent the wheel here, it was together and running, like so many similar setups.

Jim

[js73shovel]

Fair enough a little over thinking it ... Thanks a lot for all the info guys

[Revelator]

If the intake manifold has a lip to accept the oring, like the head does, and the lips are not broken, the oring is preferred BY FAR over the later flat band seals. The orings are foolproof, but can be a bother to install by yourself. If you decide to use the orings alone, you will need oring size clamps, the band style clamps are too big to be used with orings.
I emphasize again, the orings are far better than the band seals and if you have the right parts, in good shape, orings are what you should use.

Now, the hard plastic rings you found under the bands are non-stock adapter rings to allow the use of bands and/ or a band type manifold on an oring head. They just take up the space around the oring lip when a band is used.

A pic or two of your heads and intake manifold would be helpful.

Jim

I agree totally. The hard plastic adapter spacers used in conjunction with
the band seals are sort of a retro fit to adapt to the older O ring style intake,
And they are much harder to install than the basic O ring set up.
The O rings can be a pain for someone who has never installed them, But
once you get the hang of it, It's not that hard & definitely easier than the bands IMO.

Make sure you get the angle correct so that the carb lines up with the carb
support bracket ( for the SU ) And I would recommend using that support bracket.

[farmall]

One brace or more (overkill is your friend) is always a good idea as no band or O-ring manifold is intended to rely on clamp friction to support the carb.

While the thread title is "S&S" there are some very rigid, creative braces which you might want to copy: https://www.jockeyjournal.com/forum/...d.php?t=114178

[js73shovel]

Ok, looks like I am going to have to figure out a support set up. There is no existing support which I am assuming is why it started leaking in the first place...

[JBinNC]

Ok, looks like I am going to have to figure out a support set up. There is no existing support which I am assuming is why it started leaking in the first place...

BINGO!!!

Jim