The BSA A7-A10 Forum

Technical => Lucas, Electrical, Ignition => Topic started by: triangle on 25.10. 2017 19:38

Title: Electronic ignition
Post by: triangle on 25.10. 2017 19:38
Hi new to the forum but had  A10s for about 47 years  but not been used one since 1978 and the plunger since 2006.As the plunger is 65 years old i thought i would give it a birthday and use it again clean out carb and tank give it a kick or two nothing.When it was put in the back of shed 11 years ago ran perfect.Took out plugs no spark unscrew plug cap in dark shed pinprick of spark so clean up mag and points even worse so looked at price of mag rebuild and electronic ignition decided to go for electronic.(I have had it on old 750 hondas, and on a 74 bmw 750 and on the bmw 43years on gives a brilliant blue spark you can see on a sunny day.)Now the problem all fitted at 11/32 full advance it spits in the exhaust alter it by about a 1/16 on the slots and it spits back through the carb i wonder if anybody has any ideas and no i don't want to throw it away It is the wassell setup with the the polished mag conversion in their booklet they say 34 degrees full advance but i assume that is for the unit twins and i don't now how that converts degrees to fractions .HELP. Thanks Graham
Title: Re: Electronic ignition
Post by: Bsareg on 25.10. 2017 21:35
 Welcome to the forum. Might be a different set up if you have  manual or automatic advance
Title: Re: Electronic ignition
Post by: Triton Thrasher on 25.10. 2017 21:42
You’re jumping to the conclusion that it is ignition timing that is preventing your bike starting.

How are the valves and their clearances, the compression, the jets and passages of the carburettor, the battery voltage and continuity to the black box?

Having said all that, you do need a figure in degrees, to strobe time the engine once it starts.
Title: Re: Electronic ignition
Post by: Triton Thrasher on 25.10. 2017 21:43
Welcome to the forum. Might be a different set up if you have  manual or automatic advance

It needs a solid drive, with no auto advance.
Title: Re: Electronic ignition
Post by: orabanda on 25.10. 2017 23:35
For the cast iron head, strobe time on full advance to 30 degrees BTDC; for the higher tuned alloy head engines 32 BTDC.
Title: Re: Electronic ignition
Post by: KiwiGF on 26.10. 2017 03:57
Hi new to the forum but had  A10s for about 47 years  but not been used one since 1978 and the plunger since 2006.As the plunger is 65 years old i thought i would give it a birthday and use it again clean out carb and tank give it a kick or two nothing.When it was put in the back of shed 11 years ago ran perfect.Took out plugs no spark unscrew plug cap in dark shed pinprick of spark so clean up mag and points even worse so looked at price of mag rebuild and electronic ignition decided to go for electronic.(I have had it on old 750 hondas, and on a 74 bmw 750 and on the bmw 43years on gives a brilliant blue spark you can see on a sunny day.)Now the problem all fitted at 11/32 full advance it spits in the exhaust alter it by about a 1/16 on the slots and it spits back through the carb i wonder if anybody has any ideas and no i don't want to throw it away It is the wassell setup with the the polished mag conversion in their booklet they say 34 degrees full advance but i assume that is for the unit twins and i don't now how that converts degrees to fractions .HELP. Thanks Graham

Hi, do the plugs or caps need changing for electronic? I have a BTH electronic mag and use plugs with a resistor, the mag (I think) needs plugs and caps without resistors (others will confirm this).
Title: Re: Electronic ignition
Post by: Triton Thrasher on 26.10. 2017 18:36
I don’t think the Wassell ignition needs suppressor plug caps.

I fitted 5 kilo-ohm plug caps to mine because the GPS speedo didn’t like the interference.

The inductive rev counter seems less erratic with suppression too.
Title: Re: Electronic ignition
Post by: triangle on 27.10. 2017 19:16
Hi sorry to be so long in answering it has a brand new 12 volt battery when the bike was laid up it ran faultlessly the valves are not sticking the carb has been cleaned it has new ngk plug caps i am not sure of the resistance  and  the atd unit is in good condition, the instruction sheet tells you to set it fully advanced.In the book BSA Twins there is a interview with H.Hopwood in the technical data it gives ingnition timing as 34 degrees (11/32) before BTDC with the points just opening.Thanks for the suggestions i hope to have another go over the weekend.Thanks again Graham
Title: Re: Electronic ignition
Post by: Triton Thrasher on 27.10. 2017 20:09
the atd unit is in good condition

Like this?

(http://www.brightsparkmagnetos.com/images/Lucas%20ATD.jpg)

You don’t use a centrifugal auto advance with Wassell ignition, or any decent electronic ignition.
Title: Re: Electronic ignition
Post by: kiwipom on 27.10. 2017 21:47
hi TT, why not the use of ATD, cheers
Title: Re: Electronic ignition
Post by: bsa-bill on 28.10. 2017 09:51
Quote
A10.G.Flash(cafe racer)Honda 250 vtr. Yamaha Virago XV920.

Electronic ignition has sort of got it's own  A/R circuit built into it (and it's better), the mechanical unit would add an unwanted extra A/R
Title: Re: Electronic ignition
Post by: duTch on 28.10. 2017 11:47

 
Quote
Quote

    A10.G.Flash(cafe racer)Honda 250 vtr. Yamaha Virago XV920.


Electronic ignition has sort of got it's own  A/R circuit built into it (and it's better), the mechanical unit would add an unwanted extra A/R

   *conf2* yea had me there for a bit Bill, 'Specs-losers' strikes again... *smile*


Title: Re: Electronic ignition
Post by: bsa-bill on 28.10. 2017 13:58
Ha - see what you mean Dutch (pasted the wrong bit)

but I'm due an eye test right enough, apart from that I've been struggling of late seeing stuff until recently washed my glasses and found the outside surface kind of rough - then remembered spraying some bits in the garage without safety goggles - yep the penny dropped
Title: Re: Electronic ignition
Post by: muskrat on 28.10. 2017 15:04
G'day triangle.
I have Boyer electronic on both my A7 plunger and A10RR+ and both use a solid (manual A/R) timing gear. The only accurate way to time them is with a strobe light. I have a degree disk attached to the crank marked in 5 degree increments. As orabanda said 30 degrees full advance, may go a little higher for higher octane fuel (98+) or a little less for higher compression (9.5+). Here is a chart to convert distance btdc to degrees, it's in mm so stroke = 84 rod length = 164.3  http://www.dansmc.com/mc_software2.htm
11/32" = 33.75 degrees, 5/16" = a tad over 32 degrees, 3/8" = 35.3 degrees.
Cheers
Title: Re: Electronic ignition
Post by: beezermacc on 28.10. 2017 18:48
Occasionally I go on a forum about using lathes. You get chucked off if you say you need advice about Chinese lathes. Think about it!
Title: Re: Electronic ignition
Post by: Triton Thrasher on 28.10. 2017 19:04
lathes.... chucked off...

I get that.
Title: Re: Electronic ignition
Post by: orabanda on 29.10. 2017 09:12
Chinese lathes are good because they are affordable; the results come down to the machinist.

Many a bad job has been done on a good lathe (and Vicky Versa).

(written from my hotel in Beijing)

Richard
Title: Re: Electronic ignition
Post by: worntorn on 29.10. 2017 15:58
I was given a Taiwan built lathe, a Southbend copy. It was purchased new for my neighbours business but none of his employees would use it due to its tendency to always cut on a taper ( about 20 thou per foot!)
A machinist friend gave me over the phone instructions on how to adjust the head stock relative to the bed( also in the operator's manual) and now it cuts true to within one half thou per foot.
It's 30 years old but in as new condition because the employees turned their noses up and wouldn't use it, or put any effort into sorting it because of where it was built.
So it's a little beauty to run especially after I fitted a DRO to it.
I have a big Monarch lathe as well for heavy work, but still use the little Taiwan lathe for all kinds of MC work.

I had better include some Electronic Ignition info in this post. Ei is great if you can find a truly reliable 12 Volt charging source.
For timing, the slickest I have encountered is Pazon Smartfire. Put Piston at TDC compression stroke then rotate the Pazon ignition plate until the LED light turns off.
Amazingly, it works perfectly.

Glen
Title: Re: Electronic ignition
Post by: muskrat on 29.10. 2017 19:10
G'day all.
I've only ever had Boyer on my BSA's and can't really fault them. First kick starting hot or cold and check the timing once a year.
 A while back I fitted a Dynatek 2000ip system ( http://www.dynaonline.com/products/harley-davidson/dyna-2ki.aspx ) to a mates HD. Wow what a system. I can hook up the laptop and adjust everything from ignition timing, rev limit, dead crank revs (for kickstarting), adv/ret rear cyl timing and even make my own advance curve map. Every time I do a service I can download the data and see if he's been a naughty boy.
One day I'll work out how to adapt it to the BSA.
Cheers
Title: Re: Electronic ignition
Post by: coater87 on 31.10. 2017 00:33
Occasionally I go on a forum about using lathes. You get chucked off if you say you need advice about Chinese lathes. Think about it!

 We must visit some of the same sites.

 I was in a discussion about a Monarch 10EE, and some guy blurted off about how he does not know why all the bother when you can get a Chinese lathe just as good.

 He was banned for 2 weeks. *eek*

Lee