Wassell Electronic Ignition -Model 31

Information relating to the Matchless G12 or AJS Model 31 650cc twin
teebee67
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Wassell Electronic Ignition -Model 31

Post by teebee67 »

Hi,
Has anybody fitted a Wassell electronic ignition to a Model 31 AJS? Instructions say to time at full advance to Mark A (anti clock)or Mark C (clockwise). I am told clock/anti clock means from the magneto drive gear (though Wassell may mean viewed from their rotor/stator side. I set the offside piston to 11/32" before top dead onthe compression stroke (both valves closed) and aligned the Wassell timing mark to A. Attempted to startbut only mild kick backs. Set it again this time to mark C - mild kickbacks. I have set and reset time and time again using both marks with the same results. Finally on one of the settings it started but vibrated really badly and was spitting back badly through the carbs. Too retarded I thought so I advanced as much as possible on the rotor slots. Improved but still vibrating and spitting back though not as bad. As I had no more adjustment on the stator I put it back to it's central position and advanced it on the rotor - result just kicking back and won't start. I have retimed it again on mark A and mark B but again not starting, just kicking back. I am beginning to wonder if the ignition is retarding rather than advancing - the instructions say it can run in both directions (not sure how). Any help/info appreciated.
I'm only old on the outside.
SPRIDDLER
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Re: Wassell Electronic Ignition -Model 31

Post by SPRIDDLER »

I've not used the Wassell system but have read comments that although you set it at full advance the unit automatically retards the ignition (itself) for starting. However, it does need full battery voltage as if the battery voltage is even a bit low it will not retard itself.
(There's time for someone with first hand experience to help, but it's worth taking a couple of minutes to check your battery voltage even though I'm probably talking out of my crankcase breather).
'There is a tide in the affairs of men
Which taken at the flood............'
teebee67
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Joined: Mon Dec 05, 2016 8:31 pm
Location: CHESHIRE UK

Re: Wassell Electronic Ignition -Model 31

Post by teebee67 »

Thanks spriddler, I think you are right about battery voltage. I did check it early on in my struggles but I will check again to be sure.
I'm only old on the outside.
ian_5931
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Joined: Tue May 09, 2017 10:30 pm
Location: England

Re: Wassell Electronic Ignition -Model 31

Post by ian_5931 »

I use electronic ignition though not that particular type. I'm a bit puzzled by a couple of things you say - isn't kicking back and spitting a symptom of over-advance not over-retard? Secondly, you are setting the engine to the manual timing position (11/32 before tdc) but isn't it the function of the electronic ignition module to control the timing? With mine you position the engine at tdc and set the e-ignition rotor there, the black box does the rest.
teebee67
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Joined: Mon Dec 05, 2016 8:31 pm
Location: CHESHIRE UK

Re: Wassell Electronic Ignition -Model 31

Post by teebee67 »

Hi Ian,
Kicking back is a sign of over advance, spitting back through the carbs and bad vibration are signs of a retarded ignition (proven by the fact it improved when I advanced it). 11/32" is the fully advanced figure (hence you time it normally to this figure with the magneto set at full advance). The Wassell instructions say to set the ignition statically at full advance, the ignition then retards and only reaches full advance at about 2500 rpm. Thanks for the input though.
I'm only old on the outside.
SPRIDDLER
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Re: Wassell Electronic Ignition -Model 31

Post by SPRIDDLER »

I think each user has to set their engine to their preferred (or the bike's maker's specified) amount of advance since this setting varies according to different owners/makes. Not every bike needs nor owner wants 11/32" of advance BTDC.
As I understand it the Wassell unit has pre-set and generic Advance/Retard curve characteristics that apply the appropriate amount of advance or retard according to engine revs. The same factory-determined curve is deemed satisfactory for every bike once it knows where to start from - (i.e. once you have 'told' it your preferred amount of full advance. In this case when you set it up with the piston at 11/32" BTDC).

When unpowered, i.e. when th'ignition is turned 'off' the unit defaults to full advance but it sets itself to the retarded position for starting when th'ignition is next turned on, provided that the battery voltage is sufficient. In fact Wassell claim that their unit runs on all voltages between 10 and 16.

Wassell Installation and Setting Up instructions here if anyone wants a go.....:

http://www.grintriumph.com/images/Elect ... W61495.pdf
'There is a tide in the affairs of men
Which taken at the flood............'
teebee67
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Joined: Mon Dec 05, 2016 8:31 pm
Location: CHESHIRE UK

Re: Wassell Electronic Ignition -Model 31

Post by teebee67 »

You are quite right spriddler and you are confirming that the way I set it up is right. The problem with the instructions is that it is wrong on at least some of the magneto rotations - for instance it says BSA and Triumph twins are opposite rotation when they are the same (doesn't inspire confidence).
I'm only old on the outside.
SPRIDDLER
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Re: Wassell Electronic Ignition -Model 31

Post by SPRIDDLER »

The word on the street is that it was designed by and is made in Czechoslovakia by a couple of engineers who worked for Pazon and is an improved version; a cheaper and better alternative to the Pazon unit.
No excuse for incorrect instructions though as it's been on the market for some years - time enough to correct the current leaflet.

I notice that one other user has had similar experience to you (over-advanced, spitting/kicking back) and you may find this thread of interest:

http://www.triumphrat.net/classic-vinta ... ition.html
'There is a tide in the affairs of men
Which taken at the flood............'
teebee67
Posts: 61
Joined: Mon Dec 05, 2016 8:31 pm
Location: CHESHIRE UK

Re: Wassell Electronic Ignition -Model 31

Post by teebee67 »

Thanks, I had already seen this thread.
I'm only old on the outside.
teebee67
Posts: 61
Joined: Mon Dec 05, 2016 8:31 pm
Location: CHESHIRE UK

Re: Wassell Electronic Ignition -Model 31

Post by teebee67 »

UPDATE:
After trying many times I finally decided on one more attempt at both settings before I refit the magneto. Tried in the anti-clockwise position but with the stator set so I had full retard adjustment. Too advanced even after retarding. Tried on the clockwise position with the stator set to allow full advance adjustment, started 1st kick and appears to be not too far out. Problem now is that I can only advance it, I have no retard adjustment but I think this will be ok. I am absolutely sure that I have set things up exactly the same every time so I don't know what has changed this time but I am happy it is running. I am away for a few days but will "fine tune" it this weekend and then road test it. For future reference it times on the clockwise setting.
I'm only old on the outside.
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