<p style=”text-align: left;”>Hi Jonathan</p>
If the Registration No. begins with RH or VE, please advise further.
Enjoying your thread.
Both my 2-speeders were former carburettor spitters…
Neither have an inlet splitter or gauzes fitted, one is running on a 1” Amal 276 with a 190 main jet and a 3 1/2 slide and the air screw out 1 turn, the other is on a 1 1/16 Amal 276 with a No. 3 slide, the air screw 1/2 turn out and a 210 main jet…
In my case I found several conditions to increase the likelihood of spitting back through the carb:
1) Retarded ignition
2) Air screw too far out (too lean)
3) Cutaway too lean or slide / carb body worn
4) Air leaks
5) Running out of fuel
I would be tempted to try a richer cutaway on the slide, turn the air screw in a touch, double-check for any air leaks with soap suds on a running engine and check the timing…
Exhaust spitting I have no experience of, so forgive me if this is all superfluous.
A study on port sizes appears in technicalities as I recall either Potty or Tim Sharp measured a multitude of barrels and shared their findings
Highly recommended viewing…
Many thanks for putting these here Lewis.
Well done Lewis!
Reviving a 300 single is a mark of true dedication…
Keep us posted!
Best Wishes & Good Scotting this Christmas…
Super story and images.
Sounds interesting Peter.
Could you share some photos of your machine?
See you there Geoff.
I have a cunning plan to get up the hill this year…
The 1923 machine looks nicely unmolested…
Do you know which of its major components match to the Scott despatch records?
I ran my 1930 2-speeder on a 1” carburettor last season and it went very well on that.
For 1930 Scott were using amals on the 2-speeders I believe – Type 6/012 is my hunch…
I am unsure what was fitted to the 2-speeders in 1928.
The 1 1/16” bore amal carb that I have just fitted to my machine is adding just that tiny bit more urge. I gently opened-up the jet block and venturi for maximum effect.
You might try lapping in your float needle before splashing out on a new one. Dripping for a while after tickling is perfectly normal, dripping when running is not.
The jet block should not be loose either.
I fit new needle jets and slides for best results as these wear readily; particularly on neat fuel.
If your carburettur body is not much worn, you will be onto a winner.
Your Amal was original fitment to a Series B Vincent rapide. (1946-49)
By strange coincidence I sought-out and have just fitted a very similar amal 276 (DQ/1DV) 1 1/16” series C Vincent carburettor to my Super Squirrel and am very happy with the result.
I have fitted a 210 main jet, a .106 needle jet, have the needle clip sitef in the middle groove and ha ve a No 3 cutaway (with a 3 1/2 slide still to try)
Leaks you will easily remedy.
Spares are all available.
I would personally persevere with what you have.
There is an article by Ged Rumble in the August 1998 edition of Yowl.
Following some sterling work by Lewis Onions, the article can be viewed in the archive in the members section of this web site.