Gem 600 cc JAP carburetor jet measurements help

[vhgmcbuddy]

I have had to drill out a broken jet on my Amal carburetor and need a replacement jet or couple of measurements to see if I can get one made for me.

Does anyone have a jet for a 225/3 carb. If not for sale does anybody have access to one so they could provide me with a couple of measurements to help get one made please?

If successful I will ask manufacturer if extra jets could be made available to the club

[charlie]

Have you tried contacting Burlen Ltd at Salisbury, they are Amal and SU carb specialists.

[charlie]

Another thought does anyone have a parts diagram for the carb with part numbers for the jets.

[vhgmcbuddy]

Tried Burlen, they say they have no information on agricultural carburetors and passed me on to a vintage motor cycle parts supplier who recommend I contact Burlen who did have a parts diagram but no dimensions.

I tried to buy a carburetor on the well known auction site we all love, I simply doubled the sale price and still came second. I asked the seller to unscrew the jet which looked and was loose and he added a picture of it.

I asked if he could measure the overall length and a bit in the middle without a thread before he sent it to the winner and he said I should have bought it. As I explained, I tried but was out id in the closing seconds of the sale.

Back at square one..

Does anybody want my Howard GEM, as a none runner? I would sooner get it going but need the jet measurements. I still might not get one made even with the info I need

[trusty220]

Have a look at my thread from five years ago when I completely rebuilt a Norton Big 4 engine for a friend. It uses the same carburettor although it works the opposite way on the Howard but the jets will be the same.

Page 4 of “Trusty Steed Engine Rebuild” in the Projects section should be of some use; I’m assuming that the jet that you are having trouble with is the slow running mixture screw and I made a completely new one from scratch (and it worked!!).

Best of luck.

[vhgmcbuddy]

hi douglas if its any help try guypartsandservices.com on the web. talk to mike he will know about it what he does not know about all howards is,nt worth knowing.hope this helps dave.

[vhgmcbuddy]

I have a Douglas SV54 engine fitted with the same model carb, so have pulled the main jet out and produced the attached drawing. I also have a Trusty with Norton Big 4 engine and Amal 225 carb. The main jet is identical to that in the Douglas carb apart from the spanner hex on the Douglas carb is 7/16″ Whitworth, where the Norton is 3/8″ Whitworth.
I think you will be very lucky to find anyone willing to make this. Even if you do, deep pockets will be required!! Expect the cost to be well into 3 figures.

Anyway, hope the drawing helps and I will keep my eyes peeled for a donor carb. Autojumbles are the best place to find them (if any take place in these challenging times!!). Online auction sites are a last resort.

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[charlie]

Whilst getting an engineering company to make one will be expensive an alternative may be to find a local model engineer willing to make one, worth trying.

[vhgmcbuddy]

Thank you all.

Collectively your comments will help me either fix, replace or decide to sell or break my machine for parts.

I don’t want to give in but it may be the most sensible option given that the end game is to clear out an make downsizing possible.

Busman’s stunning drawing (thank you for the time and effort) means I can delve into the possibility of having one made and yes, charlie, it will have to be a rewarded favour from a hobbyist.

I will also try the company mentioned by Norton 1952 as an option

Lastly thanks to Trusty220, I would love to read your project and see how you dealt with this car but don’t know how to find it on the site. Help?

[vhgmcbuddy]

Meant to say how trusty220 dealt with this carburetor in his project.

[dave]

I have a Clifford Cultivator fitted with a J A P 600cc side valve engine
and the J A P handbook states a Zenith 24T-2 no 1467 carburetter.
So maybe you could fit a Zenith instead of the Amal.
I can scan and send you the details if required.

[trusty220]

Try having a look at the story here from my Norton engine rebuild.

Trusty Steed engine rebuild

If you click on the link above you will find it takes you to my posting; to save looking through it all the carburettor jet is on page 4.

[ssorthiek]

If you get stuck, I can probably make you one from the drawing. I need to have a look to see what taps I’ve got and will need to sort out a couple of drills, but that’s no big deal.
Let me know if you want one made but remember it will need to take a back seat for a few weeks while I try and sort out my Villiers engine.

I’m not sure you can private message now but Charlie can send you my details if needed.

Keith

[charlie]

Private messaging has been switched back on.

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