Modern Vespa

A Vespa carburetor blanking plate for pressure testing?

Essentially it'd just be a blank piece of metal that matches the size of the gasket that is under the carb box that you can use when pressure testing an engine. Or added money if one is made for inside the carb box, that'd be sweet too. Would that be better for an auto lube engine? That way you could check the oil pump gasket for any issues too. Or am I over thinking that part.
I have this rubber gasket stuff that would stick on the bottom to make an air tight seal for it if I can find someone to cut one for me?

Figure it might be a useful little piece to have in the tool boxes when testing the engines.

Hec might be your man

1980 P125X Restoration Modification Project (Page 9)

I can do it. The same local kid that's helping me with another top secret vespa bracket just bought a cnc cutter and should be up and cutting within a week or two.

If anyone is handy with a 3D printer and can draw it/prototype it now, it'll speed up the process and lower costs. My guy can do it, but it's just another added cost.

That said, it's gonna be more than $20 per blank after R&D, materials, cutting and then shipping. Would you guys honestly pay that much, or just make your own?

Do you have a junk carb that you could cut the base off of? You could fill in the hole and w/ epoxy, even epoxy in your pressure fitting and/or valve. And it would also fit in your airbox nicely too.

Why cut the base off? Just use the carb.

I would... bc I am lazy shitbird and like things to be easy peasy.
(Would also buy on of those Tac brackets if you ever have those made again.)

I do have that Honeng Chain si carb that came on my friends '62 Allstate,

But a blanking plate would be smaller to keep around ya know?

drafted it up an SI carb blanking plate, I can't print it at the moment to verify the fit.

I can also output the dxf if needed

Here's the shared model:
https://a360.co/3oFWxvI

Just go to home depot and get a piece of thick rubber from the plumbing section and cut it to slightly larger than the carb and drill holes for the bolts.

Mount the existing carb onto the engine with the rubber gasket instead of a real gasket and you've got a sealed engine.

Thats worked for me in the past.

I'll send it to the local kid (Tommy) and see if he can use this.

This is what I do, too.

This is what I did!

Piece of cake to make. Took me about 30 mins.

Hec

So I've got my guy on the job. Patrick's file is an easy one. Looks like it's meant for inside the carb box.

I'll check fitment on some old cases I have and then get some cut. I'm thinking 1/8" aluminum, unless anyone has any other ideas?

I've got dxf and ord files for this guy. Dm me Tommy's email and I'll pass 'em on. Can't post dxf files here.
IIRC the center hole is for a 1/4" barb connector.

Patrick's is easier.
1/8" steel plate.

I love when a plan comes together. Kudos gentlemen kudos!

Knew you guys were the ones to come to with this

Here is what I did for a blocking plate/leak tester.

1/2" thick 2"wide aluminum bar stock. All done by hand, and drill press. cut to shape/drilled & tapped for the barb fitting. 1/16" rubber glued to the base for sealing. When in use I smear a little grease on the rubber and it seals up great. A rubber cap goes over the exhaust stub.

I just cut some holes in a small piece of inner tube, put it under the carb box and bolted it down. Easy peasy.

Gotta do it inside the airbox. Otherwise, you're not testing one of the more common air leak locations (airbox-to-cases).

And a metal plate won't wear down as fast as rubber will.

Picking up the first iteration later and will confirm size. Then next week start cutting.

Count me in!

Like it.

Does it accommodate the carburetor hold down bolts?

That is still to be found out. If we make it 1/8" thick, I'm guessing those can press down on the plate?

Waiting for traffic to die down before I head to Tommy's shop. Will report later tonight.

The base where the bolts sit is 23.5mm ish. 1" would work too.

Patrick's print fits on a set of p200 cases. I don't have one handy, but am curious to see if the larger PX bolts are the same diameter as the older fixed studs. If not, I'll open the design up so it's a universal tool for all large frame motors.

Socalguy turned me onto some fuel resistant rubber so I'll get a sheet of that ordered too.

Anyone know where I can buy cheap aluminum sheets? Last round I just used Amazon.

Great work so far everyone! Please count me in for one of these, once production ramps up. The proto looks like a great fit, and the fuel-resistant rubber is a good idea.

I have a thought, which I took into account when making my handmade block off plate.

The P200 cases are different than Rally 200, and possibly other earlier cases as well. There is a raised portion on fly side, that is not present on P-series. This led me to make the cutout portion on the bottom of my plate. *to the best of my memory...could be worth worth checking, to make the plate as versatile as possible.

Check McMasterCarr for alum plate.

Interested in one too if I can test with the carb box.

Why not just use the 3d print with a gasket? Should be plenty strong.

This the inside-carb-box kit I made a year ago.

1/8" aluminum flexed/leaked after 2 uses.
Steel now. 1 1/4" bilge plug instead of the rubber stopper that liked to pop out.

BTW that CNC is wild!
Rotary pad repair in his future?

These guys sell small (or large) pieces retail over the counter... frequently while you wait.
https://www.metalsupermarkets.com
I don't know if there is one in your neck of the woods since their "store finder" doesn't seem to be working.

I think this is where it going inside the carb box would really make it universal, since all the si carbs are the same pin to pin distance this should cover all large frame models? Added bonus of sealing the box to the case where a lot of leaks are too.

I think this might blow y'all's minds: https://sendcutsend.com/ and https://www.fabworks.com/ offer absurdly cheap lasercut parts in aluminum (and other materials including steel) up to 0.5" and 0.25" respectively. Very low minimum order quantities (technically no limit, but $30 minimum order). I've had dozens of random brackets, blanking plates, and even phenolic spacers made by them.

This part looks like a perfect candidate for that, considering it only needs to be a 2d profile. I have a CNC router in my garage that would make quick work of this type of part, but outsourcing to those guys is way less of a hassle for simple stuff between qty 3 and 50.

One of the really cool things you can do is get a public, preapproved SendCutSend cart link, so other people can order using that link directly and don't have to worry about getting the wrong material or thickness or whatever.

Went with Fabworks as Tommy is still figuring out the CNC machine. Fuel resistant rubber should show up today and I'm hoping to be able have them ready to ship tomorrow. So, if you want one PM me. I have 8 for sale right now. Price is $11 plus shipping. That covers my costs and makes sure Patrick gets a free one for his effort.

I'll gladly take one, and no need to make it free. You made it a reality, I just spent 5min drawing the shape based on measurements I already had for my carb project.

Well done!

They look great!

PM sent

Pm obviously sent.

Love how easily this came together. Thank you gents!

great work!

Set up complete. Perfection! Thanks again for getting my hare brained idea produced MJRally.

Hope this helps everyone out too. Much better looking solution to keep in a pressure test kit if you ask me. I'm biased though.

Thanks for the beautiful addition to my leak down test kit