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[Adrian]

Rattlebattle, it has a Thorspark electronic ingition conversion fitted in an old SR1 magneto. Sadly the formatting glitch makes this post hard to read (at least in Firefox).



Chris, do these conversions keep any auto a/r unit fitted to the mag, or did you have to swap to a plain mag pinion? Could be a rogue connection causing stray sparks, or a fault in the TCI unit, which might be a case of getting a warranty replacement. Talk to your supplier.



A.

[Rattlebattle]

You get the choice with Thorspark (ie manual or auto advance).

[Chris Tindal]

Had the battery on charge today and tonight it has started with no kickback. It uses the original SR1 a/r unit so it's difficult to understand how the ignition can become advanced. The tickover is however very lumpy and it feels to be eight stroking . A quick run around the block and it runs ok above 1/4 throttle but at low speed it's very rough and vibratory. I've adjusted the air screw but it's very lumpy. Before the top of the carb unscrewed on Sundayit was running really smooth and had a steady slow tickover. I'm happier it's started but don't understand why battery with lower charge causes sudden kickback, and now a very lumpy tickover. Thanks for the help so far, everyone, hope you can read this Adrian.

[Adrian]

Hi Chris,



for some reason your messages spread well to the right of the normal "box" that appears within the Screen.



Your Thorspark sounds like it's got Boyer Mk3-itis, too low a voltage and it goes full advance! Replacement TCI needed?



A,

[Chris Tindal]

Tonight it started first kick, no kickback. I re checked the ignition timing (again), checked the cold tappet clearances, set the pilot screw/tickover to a slow steady beat and all seems well. Adrian I still don't understand how low voltage can alter the ignition timing when it relies on the mechanical a/r unit in the timing cover bulge. I'll give Thorspark a call tomorrow and see what they. I must say that despite this issue, the electronic ignition has transformed the bike and it has been so much easier to live with and reliable. I just hope all these kickbacks haven't damaged the oil pump spindle. Thanks for all the replies and suggestions.

[Count Johnny]

Hi Chris



Having recently suffered two oil pump spindle failures - one of which dumped me, sur le Continent, en-route to Germany - I would physical check the oil pump spindle (a simple matter of popping off the timing cover) rather than hoping that its OK.

[Adrian]

Sorry Chris, brain failure... ( A.

[Chris Tindal]

Hi Count Johnny, I'll be checking, its a freshly rebuilt engine and I'll not risk it getting wrecked.

[Chris Tindal]

Just had a chat with the makers of Thorspark. As suspected, the kit does not have any influence on ignition timing, that is dealt with my the existing mechanism on the bike its fitted to, in my case the a/r unit on the end of the SR1. Its much simpler than other kits which have advance retard built in electronically. This doesn't solve the kickback issue so I think its just coincidence.

[Jamesy]

The inbuilt electronic advance/retard could possibly be faulty?If also any fluctuating voltage is going on it's going to upset any timing signals I would have thought.