The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Lucas, Ignition, Charging, Electrical => Topic started by: Gerry on 10.06. 2019 05:56

Title: A10 carb comes good or is it the plugs
Post by: Gerry on 10.06. 2019 05:56
Hi again all, Well I have been having bloody awful starting problems on the A10 for a long while. Kick it over about 10~12 times and maybe it will start. Been running on NGK B7ES plugs and yesterday, Sunday being a club run, thought I'd take her on the run (if I can get her started). So Saturday decided to get a new set of plugs and fitted them (no change in brand or type)
Kicked her over and bugger me she started after the second kick. Left her to cool off and tried again and this time first kick!!! So back to the shop and got four more new NGK plugs and put them in the tool box. Following day, Sunday, got all my gear on and kicked her in the guts and away she went first kick again. WHAT THE BLOODY HELL HAS HAPPENED TO CHANGE. I know there has been some talk of NGK not being the best plugs for the A10 and Champion being better but have had trouble sourcing Champion plugs to try them. Got to the club rooms after a 20 minute ride and waited for the 09.30am start. Kicked her and away she goes again first kick. Sat there with her idling while watching a few others kicking away vainly he he (I can be a rotten bugger at times). I recon we did about 200 miles in all plus a couple of stops for tea and cakes and then dinner and again she started so easily. Incidentally she ran beautifully and it was the first run since getting her back together after the run in with the Armco barrier.I've been playing around with the 376 carb previously with no great results other than to change the idle jet from a 25 to a 20 to get a good tick over with the air screw turned out about 2 1/2 turns. So come on guys tell me what are your thoughts? Gerry
Title: Re: A10 carb comes good or is it the plugs
Post by: Triton Thrasher on 10.06. 2019 08:31
Plugs first, then points.

That’s what they used to say in garages.
Title: Re: A10 carb comes good or is it the plugs
Post by: muskrat on 10.06. 2019 08:34
G'day Gerry.
It must be the weather, it's a pommie bike and likes our winter. Just pure coincidence, the new plugs wouldn't have anything to do with it  *sarcastic*
 *bash*
Cheers
Title: Re: A10 carb comes good or is it the plugs
Post by: Swarfcut on 10.06. 2019 08:43
Gerry, if you can pluck up courage to break the spell, put the old plugs back in, see how you go. There were rumours of fake counterfeit NGK plugs,  so another possibility, maybe.

 Swarfy.
Title: Re: A10 carb comes good or is it the plugs
Post by: Gerry on 10.06. 2019 10:51
Hi Muskrat and Swarfy, Well I have read on here previous posts suggesting NGK plugs do vary depending on where you purchase them, such as eBay selling counterfeit items but all the plugs I have bought have come from two reputable motor parts shops. I will replace the original plugs that gave me such a really strong right calf muscle and see what the difference is.
If still starting first or second kick I'll be bloody stumped as nothing else has changed unless all of a sudden the carb has dislodged a piece of crap from one of its passageways with the vibration, but that would be a long shot. I was told that due to my having to give it a fist full of throttle as in wide open when kicking that the problem was a weak mixture and there was no other way to start it previous to the plugs change. I've had maybe 8 or more plug changes since I first got her on the road about 5 years ago and in all that time she has been hard to start. Now I find the lack of tension I am feeling due to the ease of starting is such a pleasure and makes the ride so enjoyable when not wondering how many blokes are going to have a go at starting her after I fall over completely shagged. Cheers and thanks fellas. Gerry 
Title: Re: A10 carb comes good or is it the plugs
Post by: Triton Thrasher on 10.06. 2019 10:59
Needing a lot of throttle for starting usually indicates a rich mixture.

You have, of course, renewed the needle jet at some point?
Title: Re: A10 carb comes good or is it the plugs
Post by: Gerry on 11.06. 2019 00:45
Hi there Triton Thrasher, No I haven't replaced the needle jet. I should stop being a tight bastard and maybe change out all the jets and needle for new but why the change suddenly to a bike that starts first or second kick from one that would only start after many many kicks and only then with a flooded carb and a wide open throttle. I tried every other way of starting and nothing else worked. I will replace the previous plugs though just to see if that was the problem. When I feel up to it. lol
Cheers Gerry
Title: Re: A10 carb comes good or is it the plugs
Post by: duTch on 11.06. 2019 08:48

 
Quote
...... from one that would only start after many many kicks and only then with a flooded carb and a wide open throttle.......

 Well that's about the same as ;

 
Quote
  Needing a lot of throttle for starting usually indicates a rich mixture.
Title: Re: A10 carb comes good or is it the plugs
Post by: Gerry on 11.06. 2019 10:04
Hi Dutch, Well I would assume it would be rich due to flooding the carb but correct me if wrong. OK replaced the new plugs with the previous set and she still starts easily with around 2 or 3 kicks so I am leaning towards it being a carb problem that somehow has corrected itself??? Before replacing the plugs I tried starting her with a closed throttle and no flooding and she fired and stopped a few times before ticking over like a swiss watch. Anyhow I am as pleased as punch to at last, after many years of trying and failing to find her many problems (A7 long stroke crankshaft pinion, head gasket, inner timing cover with a very thin gasket area below the large dynamo cog. Mixing the grease with the oil, plugs and quite a few carbs). Maybe now I can enjoy her like an 81 year old should be able to. Thank God I didn't listen to my wife saying "sell it" Cheers. Gerry
Title: Re: A10 carb comes good or is it the plugs
Post by: duTch on 11.06. 2019 10:40

 I can't comment much more on the dark magic of it all, but;
 
Quote
......., inner timing cover with a very thin gasket area below the large dynamo cog. ......

 I had that where the interfaces were over/under lapping by about half, so had the outer cover bit built up with weld and dressed it down- and the belt drive sprocket was a close fit to consider, but so far so good ...was "a fine line between pleasure and pain" (Chrissy Amphlett)
Title: Re: A10 carb comes good or is it the plugs
Post by: RDfella on 11.06. 2019 11:03
Fuel that’s over three months old, or plugs that have got wet with fuel at some time in their past can make a bike difficult or impossible to start, especially ours with magneto, where the spark is weak at start-up. But your’s sure is a mystery.
Can’t think of anything more demoralising than a bike that refuses to start, especially those that are hard to kick over (ie harder than an A10). If I don’t get a sign of real life after half a dozen kicks I walk away, come back when in a better frame of mind and start by looking at plugs and remembering how old the fuel is.
Title: Re: A10 carb comes good or is it the plugs
Post by: Triton Thrasher on 11.06. 2019 12:24

 
Quote
...... from one that would only start after many many kicks and only then with a flooded carb and a wide open throttle.......

 Well that's about the same as ;

 
Quote
  Needing a lot of throttle for starting usually indicates a rich mixture.

But different from:

Quote from: Gerry
I was told that due to my having to give it a fist full of throttle as in wide open when kicking that the problem was a weak mixture