BSA Owners' Club Workshop Discussions

The BSA Workshop => Singles => Topic started by: Dickthebass on 06 Oct, 2020, 20:50

Title: B40 starting problems.
Post by: Dickthebass on 06 Oct, 2020, 20:50
I know very little about mechanics.
However my B40 with electronic ignition used to start first kick every time.
I replaced the clutch a week ago, whether or not this has anything to do with it I have no idea,
however if I start the bike now and ride For a few mile and stop the bike for say 5-10 mins the bike refuses to restart, it will start with a bump. Maybe an hour later it will start with the kickstart again fine.
While riding the bike it's going fine, just as good as it ever did.
I have not made any adjustments to the carb at all, after tickling the carb , and after kicking again and again, I check the plug, I think it looks dry..?
Plenty of bright blue spark, with the plug out..
I suppose I should Try and enrich the mixture, .?
Any suggestions, before I start messing with things.?
Many thanks.
Title: Re: B40 starting problems.
Post by: LightningAndStarfire on 06 Oct, 2020, 21:18
Hi, does petrol flow and drip from the tickler?

Not sure when reading your procedure if you tickle also with a hot engine. Don't think that is advisable.



Title: Re: B40 starting problems.
Post by: Dickthebass on 06 Oct, 2020, 21:23
Only tickle it when first starting from cold, And yes petrol flows.
Title: Re: B40 starting problems.
Post by: MGILBERT on 07 Oct, 2020, 08:12
make sure your clutch adjustment is all ok after fitment. similar problem on my bsa b25 was slipping on start up.
Title: Re: B40 starting problems.
Post by: craigc11g on 07 Oct, 2020, 08:20
are you running a battery with the ignition or a self generating system ?
Title: Re: B40 starting problems.
Post by: Dickthebass on 07 Oct, 2020, 18:44
I am using a battery with ignition switch,
I thought I had the clutch set ok, although I did think that this may of had something to do with it,
there is no sign whatsoever of the clutch slipping Whilst riding the bike, even up the steepest of hills,
Likewise when bumpstarting the bike, the clutch seems to be ok, I will however give that a try at the weekend, and tighten the springs a bit more.
Title: Re: B40 starting problems.
Post by: AdrianS on 07 Oct, 2020, 21:47
Doesn't sound like the clutch. If the bike doesn't cut out when running I doubt anything is wrong with the electrics.  I would clean the carburettor out first. Make sure there is no dirt in any of the jets and fine airways. Make sure the float is sound and the needle valve is good.
Title: Re: B40 starting problems.
Post by: Dickthebass on 08 Oct, 2020, 21:52
Yeah tried all of that, already.☹️
Title: Re: B40 starting problems.
Post by: craigc11g on 09 Oct, 2020, 09:34
sounds like a weak spark when hot , if it had standard ign  i would change condenser , whos system is it ? wassel sell a system which i have had problems with made in hungary i think , not good .
Title: Re: B40 starting problems.
Post by: DAVE BRADY on 09 Oct, 2020, 10:32
Hi,

Tickling the carb to overflow the float chamber shows that fuel is getting to carb but there could still be a bit of a blockage.  Just enough getting though to start when cold or with the extra suck of a bump start and running engine.  As suggested start by cleaning the pilot jet.

Dave.
Title: Re: B40 starting problems.
Post by: jodie89 on 09 Oct, 2020, 17:21
 Fuel vapourisation in the carb when you stop? I had a similar problem with a C11G, fitted a tufnol spacer between the carb and head and the problem stopped.