A10 Golden Flash Carb

[beezalex]

So it won't run at all without a restriction, or it just won't idle?  The idle jet on concentrics blocks quite easily, particularly when they sit.  You can check whether or not the idle circuit is working by seeing if the bike reacts to the air bleed screw (the horizontal one).  If it doesn't, you have to drill out the plug on the opposite side to get to the jet and clean it out.  You can either replace it with another plug or, what I do, is tap it for a 1/4-20 setscrew that can easily be removed anytime.

BTW, I run a 928 concentric on my 53 Flash without an air filter (I can't find one), and it goes like the clappers.

Cheers

-alex

[peteb]

Thanks Alex for your thoughts

No the bike will not run at all without a restriction.  Once running the engine does respond to movements of the air screw so I am happy that the pilot circuit is clear.

With the restriction in place the bike starts and runs quite happily up to full throttle, but remove the restriction at any position of the throttle and it stops.

I've sourced a second hand 276 in good nick and will try that next, just need to get hold of some fuel pipe to fit it first.

I think I may have a 928 lurking in the back of the shed somewhere - do you know what your jetting is?

Cheers

Pete

[beezalex]

I'll have a look at the carb this weekend and let you know.

[beezalex]

Allright, here are the numbers:

Slide = #4
Needle position (STD 4-stroke) = 3
Main Jet = 190
Needle Jet = .106

Cheers.

[Stu]

Hi, probably a bit late for this but I have a 61 a10 gf issuiong 626 Amal concentric mk1. I read the standard jets are 160,106 but the bike has 170,107 and it runs too rich. The bike was raced years ago so I'm assuming it was run without silencers, hence the bigger jets. I will replace with the original ones but might also test author the silencers to confirm the problem. I also tried a new pancake filter but it won't run nicely so the comments above about no filters seems correct to me, it just doesn't like them. It's strange that it's a rare thing as mentioned above to use 626 on a10, the bike has been in Zambia since 1969 so maybe there was a problem getting the correct one here back in the day, either way, a 626 will work, I just think 190 jet is way too big which would mean you must have a massive amount of air leaking in for it to still be lean.

[chaterlea25]

Hi All,
In the first post of this thread it says a 25 pilot is fitted to tbe concentric
Unless it is a new or very old one the pilot is the non removable plug pressed in
It may be the case that someone added a screw in pilot jet as well which will cause a very weak mixture and starting issues

John