Vm26 how to replace plunger pad

I believe im having this issue with one of my carbs and am going to order some material and lathe out a couple punches.

I could probably make a few sets if anyone wants them, but you're responsible for digging out the old ones.

jetsrus.com/individual_parts/002_670_su.html

You don't have to "dig" them out. Just soak them in some paint remover. They swell-up, so you can just fling them out. I used to use the old formula of Berryman's that did the same thing. I had a batch of these (500) made but still cannot find them since the move?? Thinking the actual sheet was in the 2mm thickness range but it's been 10-12 yrs ago? I had Hanna Rubber of KCMO punch them out for me. I think i paid around 500.00USD at that time for set-up and product for Hanna. That's why i'm sorry i cannot find them. I've had the Keyster flat pads just fall out on a couple of triples i was working on years ago, YES just watched them roll across the floor and under the workbench. The material either shrunk or brass wasn't rolled enough.

Saablord wrote: I believe im having this issue with one of my carbs and am going to order some material and lathe out a couple punches.

I could probably make a few sets if anyone wants them, but you're responsible for digging out the old ones.

No reason to reinvent the wheels. Go back into this post and look for zed1015’s replies. He has already figured this all out

I just posted this. They are the same VM 24 - VM 33's. The ones without the pins won't work correctly. God only knows what else I'll find when I replace them in my 33's. On startup it seems it floods if I don't feather the choke lever. I suspect there's another flat one in there or maybe two.
Steve

Mikaw wrote:

Saablord wrote: I believe im having this issue with one of my carbs and am going to order some material and lathe out a couple punches.

I could probably make a few sets if anyone wants them, but you're responsible for digging out the old ones.

No reason to reinvent the wheels. Go back into this post and look for zed1015’s replies. He has already figured this all out

And if you can get the pads fitted in the plunger freehand without marking the seal or splitting the brass retaining edge you'll be lucky unless they aren't the correct size.
If it was that easy i wouldn't have spent months developing the tooling and the lubricant assisted insertion rig to enable them to be installed correctly without damage.

I didnt know jetrus had new plungers... nice!

Huh. i did not get any topic notifications for this. I went full steam ahead as i did not know any replies were posted.

It wasn't too difficult to pull out the old seals without damaging anything. they were 6.75mm (od) x 2.1mm (id) x 2.15mm (thick).

I ended up using high strength buna-n 50A 3/32" sheet which should last another 30/40yrs like the original material. The 50A material made it way easier to slip the new seals in.

My punches left a slight taper on the OD of the seal, so even though the 3/32" was a bit thick, they fit perfectly. Leaking chokes was definitely the issue with my carbs... lol

Crap! I always have a better idea after the fact... I have 2 part urethane rubber sitting on my shelf. This stuff is also gasoline resistant and wouldve been perfect...

Pull the old seal out, tape off the plunger, mix up some urethane and pour it in. doh.

Edit: use a syringe to fill the plunger and ya dont even have to tape it!

Buna-N should be fine. Viton is better for high temps but the carbs won't get hot enough to harm Buna-N.

Unless you are using non ethanol fuel the Buna N ( Nitrile) is not ethanol compatible and will degrade and it is the inclusion of ethanol that greatly accelerates their demise.
Replacement Nitrile seals won't last another 40/50 years due to their ethanol exposure from day one.
This is the reason i only use high grade Viton for my plunger seals and the reason all relatively modern fuel systems have switched from Nitrile to Viton too.
Viton is the only seal material suitable for modern fuels containing ethanol.
The 50 shore is also a little soft and it's less dense open grain will more rapidly absorb the ethanol leading to a faster failure.
75 is comparable to the original seals.