honda xl 250k1 poor/no spark

[beeman]

HELP
Having Major problems with ignition system.
bike has stripped down electrics.  wire from magneto to coil, condensor , kill switch, and points.
Gets a good blue spark then to poor yellow spark then just vanishes. I have been methodical and changed one thing at a time so as not to complicate things to much. So far all wiring replaced including connectors, 2 coils including leads and caps, 3 condensors, 2 spark plugs, 2 sets of points and the magneto itself. I have replaced everything bar magneto rotor.

If I clean points which get some pitting it usually comes back and works for a while, sometimes 5 mins sometimes up to an hour.

What am I missing, local garage had it for a while but he couldn't find anything either.

I think it may have something to do with the points set up but not sure what as set to honda settings. When running the engine sounds and goes well.

Any suggestions?

beeman

[SteveC#222]

I don't know if it helps, but there is a ignition module kit by Velleman  which retains the points as an on/off switch but the spark is electronic - I've used one on an MZ and it works really well. I sent my old one to Bill (moudie) for his Ducati.  It will fit any bike/car and does away with the condenser etc. They were sold through Maplins but they don't seem to do then anymore but I've found this place that has them.

http://www.theelectronicsshop.co.uk/contents/en-uk/d31_Automotive.html

They only cost £11.  Might be worth a try.

[Propellor]

Condenser? (Capacitor).

Used to be a source of trouble on points systems.

Just a thought.

Cheers

[beeman]

Thanks for that.  Looks like I will order one in the morning Steve. 

[SteveC#222]

Thanks for that.  Looks like I will order one in the morning Steve.

It is a kit so you get a printed circuit board and a load of diodes you have to solder yourself but I managed it and I'm hopeless on stuff like that.  It comes as a 12V unit but I believe it's possible to change a couple of the diodes to a different value which lets it run on old 6V systems as they used them as an upgrade on the old 6V Vdub Beetles and buses.