Author Topic: a10 stalling and spitting back  (Read 89 times)

Online madsens

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  • 1962 A10 GF - Fyn, Denmark
a10 stalling and spitting back
« on: 08.07. 2019 11:31 »
My A-10 has begun to stall and  backfire.
I had the top and magneto off, and after putting it all together again, and timing, setting tappet clearance, this is what happens:
Starts easy enough, and seems to run smoothly - but after a short drive when everything is warmed up the trouble starts... when stopped a traffic lights/crossroads or anything else and on idle she suddenly stalls - and when trying to start her again she backfires, and is generally very hard to get running again, then after some rest/cooling down (both bike and me  *pull hair out*) she starts ok again...
Magneto was of to be checked and works fine with Easy cap installed - can this problem be due to blocked pilot jet? worn slide? any suggestions to where to start?

For information she was running perfectly before - until a slipped magneto camring had me dismantel magneto, top was taken of to put new gasket on.


BSA A10GF 1962

Online Triton Thrasher

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Re: a10 stalling and spitting back
« Reply #1 on: 08.07. 2019 11:46 »
Don’t theorise about a blocked jet: clean it.

Check for manifold air leaks by spraying the joints while the bike is idling.

Online RDfella

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Re: a10 stalling and spitting back
« Reply #2 on: 08.07. 2019 12:36 »
So it’s a problem only when warmed up. Either petrol is getting hot in the carb – have you got a tufnol insulator between carb and inlet? or the mag condenser is kaput.
'49 B31, '49 M21, '53 DOT, '58 Flash, '00 Firestorm, Weslake sprint bike.

Offline morris

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Re: a10 stalling and spitting back
« Reply #3 on: 11.07. 2019 21:50 »
Don’t overlook your timing. If the magneto has been off and you timed it a bit early it may give the symptoms you describe.
'58 BSA A 10 SA
'52 BSA A 10 Plunger
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