Author Topic: Starting A10  (Read 871 times)

Offline Rich

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Starting A10
« on: 09.08. 2019 09:05 »
I have put this on here as it must be Carb related,
having finished the Gold Flash and finding out the mag was breaking down when hot, I fitted a Thorspark ignition system until a mag rebuild in the winter months, anyway, both with the mag and now with the Thorspark, to start the bike, I have to tickle the carb and then kick it with the throttle nearly wide open, it will start first or second kick and then tick over nicely, I have done 40 miles now and it pulls and runs well.
It will not start with the choke, I have the original air filter fitted. All my previous BSA's have started with no or very little throttle.
Is this a common thing? or do I have a carb problem?

Offline Klaus

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Re: Starting A10
« Reply #1 on: 09.08. 2019 10:03 »
Hi Rich,
I think so, its too rich, check the pilot jet or srew out the idle needle to lean.
When you rise up the trottle the carb get more air.

Klaus


If you think, everything is under control, you are not fast enought.

BSA DB34 Goldstar, BSA A10 Road Rocked, BSA A7 Shooting Star, BSA M33, BSA M24, Kawa W650

Offline duTch

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Re: Starting A10
« Reply #2 on: 09.08. 2019 11:44 »

 Maybe try to not tickle it so hard   *conf2*
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Offline RogerSB

  • 1960 Golden Flash, Plymouth, Devon, England
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Re: Starting A10
« Reply #3 on: 09.08. 2019 12:58 »
Or try kicking harder  *smile* only joking Rich.

My 1960 G/Flash only needs choke if it's really cold. After flooding the carb it usually starts first or second kick but always needs an initial twist of the throttle, then I leave it on a fairly fast tick-over while I check the oil tank for a healthy return, by then it's good to go.

My 389/45 carb has all the standard bits and settings (i.e. 250 main jet, 30 pilot jet, 3 1/2" throttle slide, 0.106 needle jet, D needle on 3rd groove from top, is correctly set up and using the original BSA air cleaner. None of the parts are new (as I've not seen the need to replace any) so probably a little worn. I'm using Champion L85 plugs and they don't get abnormally sooty, so I don't worry about not having to use the choke every time when starting from cold.

I do however, these days, use premium petrol with a lead replacement additive in my A10 and I definitely noticed improved starting and running when I changed from using straight 95 unleaded from Asda to BP Ultimate from a petrol station.

You probably know all this but just in case I've attached a couple of charts that I've made as picture files for setting up Amal Monobloc carbs.

1960 Golden Flash

Offline lawnmowerman

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Re: Starting A10
« Reply #4 on: 09.08. 2019 13:16 »
Very useful charts Roger. Now printed out to go on the garage wall to aid my intermittent memory  ;)

Jim
1959 A10 SR
1938 Wolseley 14/60
1955 Ferguson TEF20 tractor
1965 Ferguson 135 tractor
1952 Matchless G80 rigid
1960 BMW R60
1954 Matchless G80S
1955 Ariel 500 VH
1951 Sunbeam S7DL
1960 Matchless G12 with Watsonian Monza
......and loads of lawnmowers

Too old to Rock and Roll but too young to die  (Jethro Tull 1976)

Offline Rich

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Re: Starting A10
« Reply #5 on: 09.08. 2019 19:21 »
I am not sure if it is running rich, as the carb is set as it was when I got the bike it may not be rich, but as Roger has written it may be normal, however once the weather improves and I can do some test runs, I will follow the chart for setting up.
I will not have time to do anything before the Sunday ride to the International at Morton in Marsh

Offline Gerry

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Re: Starting A10
« Reply #6 on: 10.08. 2019 08:57 »
Sounds exactly like the problem I had with my 59 bitsa A10. Wouldn't start unless I tickled the carb and then full throttle to start and then only after many tries usually with someone else having a go after I fell in a heap. The 25 pilot jet wouldn't allow me to tune the idle so tried a 20 and that worked out ok for tick over but still had the problem. Low and behold about three months ago I changed the plugs and second kick away she went! Put the old plugs back in and she still started first or second kick. My feeling is it was a blockage in the carb somewhere that eventually vibrated itself clear as there is nothing else I have done to it to cause the improvement. Anyone tried ultrasonic cleaning? Cheers Gerry