Amal MK 1 carburettor - clearing blocked pilot jet passageway.

Many of these carburettors are discarded due to poor starting and idling problems, but in many cases, the pilot passageway is probably blocked and just needs clearing, to correct these issues. Here, Paul Henshaw at Performance Classics demonstrates one method of dealing with the problem.
Note - although not mentioned in the video, the access hole drilled in this instance was, of course, plugged again afterwards !

[jrpjrp]

Really good vid, helped me sort my blockage. Only thing to add is a short length of guitar string (Think it's the third)
Is just the Amal recommended .016" size to go through. I started it in the hole then gave it a spin with a power drill job done.

[iandawson]

Thanks for making this tutorial, I'm having some real problems just like you have described. Spitting back through the air filter and putting the engine out and continuous stalling at lower revs .😫..

[markgriffith]

My friends and I use the smallest guitar string; I think it is .009”, very strong and stiff. Worked on my ‘69 Bonnie nicely.
Possible to drill and tap the opposite side and use it for access on the close side and plug it after clearing. Appreciate your site !!

[steveyard]

Thank you Paul. Have exactly those symptoms, spitting back through the carburettor and very poor idle. Will have a go at cleaning out my carb.

[timcollar]

what a great video . very clearly presented, I have exactly the problem with the poor tick over you describe. Will now attempt to correct it as shown.
Many thanks .

[SempreGumby]

Paul remember the two holes in the center on the bottom of the throttle tube on either side of the back of the slide. The tickover fuel and air has to have somewhere to go after they have been mixed. Those two holes must be clear as well.

[baronlowie]

I pull a wire from a wire brush for this kind of job, very stiff and works well.

[rossallen]

my 1967 trophy was only running on one cylinder and wouldn’t idle tried your trick used the wire out of a mig welder now she runs perfectly thanks

[jonathanredman]

Very useful video. Thanks for posting.

[lippythelion]

Cleaned my 72 a65 thunderbolt carb pilot jet like this tick over like a watch thanks

[jaydubbleya]

Guitar string (thinnest) worked a treat for me. Pilot jet clear, now off to buy new set of strings!

[hayabusabart]

thank you. I think that the blocked pilots are the problem on my T140v will strip them tomorow

[oscarsanchezmendoza]

thank you, I cleaned mine a couple weeks ago, will have to do it again. starts but no idle. Initially i didnt have the right wire and thought it was good enough.. not so.

[markpedwell]

Thanks for sharing your knowledge its very much appreciated, my 68 A65 had rust particles in bottom of the float bowl and now wont start, I think these passage ways must be blocked I will have a go at clearing them 👍

[grahamseward]

The hole from there into carb throat gets blocked as well, you can just drill out the jet with a 2.0mm drill taking care down the pilot screw hole taking care not not to damage the air screw seat you then put a new jet into the threaded boss in the top of the carb body float chamber usually used for 2 strokes

[petergoddard]

Just an idea, but a fine gauge guitar or banjo string might be fine enough. Thanks for the clear info on that.

[MrConan]

Good advice. Method to re-seal drilled blank would be good to know.

[markschmalenberger]

The primary discharge ports, located on the floor of the venturi, clog up. The only way to clear them is to prick them clear. I use guitar string. It worked like a charm of the worked like a Charm on my 72 Trident..

[philgreenges]

Hi Paul great video question
My bsa a65 concentric is pretty new ran great last year now it’s well blocked
Do you know the max size drill I can use it says #78 drill equals to .40mm

If I use a 0.6mm drill would this do any damage to the pilot system
Thanks a lot phil

[Retro]

Would squirting a big of carb cleaner in the holes help things along?