Better washers than fiber

Hey Guys,

I’ve never been a big fan of the fiber washers used on the HD8 carbs. Has anyone found any better? Perhaps “Posi-Seal” or “Stat-o-Seal”? Am digging into the cause of a leaking overflow tube and will like to replace the washers involved.

The fibre washers where? If the overflow does its job it’s the needle valve.

David, my thoughts exactly. As I mentioned, I’m not a fan of fiber washers. In any number of instances in my 50 years of ownership, I’ve come to not like their sealing, without, in a number of cases, having to exert more torque than, I feel, is necessary.
Was just curious, if anyone else has discovered a better replacement. Not looking to debate the virtues. Thanks for your reply.

I would always soak the fiber washers in Marvel Mystery Oil before install, and never seem to have too much of a problem with them sealing after that.

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Good idea Wiggles! I’ve done that with cork, but, not with these fibers. BTW, why Marvel? Because you have it on the shelf?

Only because it’s thin: any 10 or 20 weight straight oil will work. Sewing machine oil will work. ATF will work.

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Which washers are you speaking of exactly? There are fiber washers on the fuel rail, and on the overflow tubes. IIRC though the ones on the tubes are special though. They have little interior cutouts to allow the bowls to vent. I would not substitute anything for them. I do not apply high torque to the top fuel bowl nuts. They will definitely strip, and it’s not really necessary. If you’re seeing a lot of leakage up there you have a bigger problem. It means your float valve is set wrong, or defective.

It’s also possible you have a cracked solder joint on the overflow banjo. I’ve had that happen as well.

At one time the various vendors supplied aluminum washers for the HD8 carb inlets. I haven’t seen them in some time. That said, I’ve never had a problem with the fiber washers.

Statoseals have neoprene inserts, they’ll be trouble, especially with E10. You also have to consider the thickness of the washers, as the depth determines how the bolt orifice matches to the the banjo.

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Thanks Erica, I wasn’t thinking of them, so much, as the rail gaskets. I’ve never had a problem with top fuel bowl gaskets. Thanks for your input.

I’d add that the overflow tubes are the least likely to leak, because the fuel level should be well below the level of the overflow. Make sure you have good needle valves. Also make sure you use the oddly punched washer under the banjo.

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These are my go to if I can’t get a fibre washer to seal.

The fibre ones if used on the fuel rail need to be done up a lot tighter than you think (and may be comfortable with). I have a foot long 7/16" Whitworth ring spanner I use for this.

A Whitworth wrench is necessary, unless you like rounded bolt heads.

I suddenly have tool envy.


I think I still have a bunch. IIRC they came in rebuild kits.

I have one.



Wiggles, I have a bunch of those, but I always thought they were Japanese adjustable metric wrenches… LOL

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Yeah, but this one shown is only for loosening. You need a different one for tightening.


While waiting for parts and soaking washers, I decided to test the brass floats for leaks. I did this by place them in a pot of hot water. As it turns out, no leaks. Then, since I have scale nearby (weighing dog food) placed each on the scale…HUH? 2 weighed 22 grams, the 3rd was 25 grams. All three measure the same in DIA. & Height. Each has the same profile. BTW, these are HD8 SUs.
Anyone have an idea?

One might have more solder? You could add weight to the others.

Two have been lightened for racing? I wonder if the “big boy” floats as well as the “lightweights”? :open_mouth: Jaguar’s poor quality control maybe? I think I read somewhere that they’re supposed to weigh 23.5g but I can’t find anything in the manual to confirm this - J-L overthinking?

OK, back to your leaking issue, as suggested earlier by Erica, check the fuel bowl needles & seats and then make sure all of the float levels are set correctly - but you don’t need to weigh anything! :smile:

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