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Old 10-28-2012, 02:43 AM   #57
_cy_ OP
Beastly Adventurer
Joined: Sep 2011
Location: Tulsa, Oklahoma
Oddometer: 6,316
Originally Posted by Bulldust View Post
I found one of the greatest problems with the BMW system was the wear associated with the mechanical advance system within the stock beancan, and the fact that a failed Hall Effect sensor meant you were off the road. One could carry a spare bean can, but that is bulky, one could fit an additional Hall Effect sensor to a stock BMW beancan but that would leave you with the mechanical advance system.

My solution?

Make my own system with a true electronic advance within the ignition module.

Fit a twin plug system that is fully redundant running separate coils. So now if a Hall Effect fails, change over the plug to the spare, a failed coil will not stop me as the redundant system takes over, and carring a spare ignition module is an easy solution should that fail.
Bulldust, pretty slick system ... but track history indicates very low instances of mechanical advance failures on airheads. let's say one does develop sticky advance weights. odds are motor would not run optimally, but it would still run to keep you from walking.

solution is usually a spray with WD-40 or other penetrating oil and you are good to go for many more miles. this would fall under preventive maintenance before a long trip.

modifying your own BMW beancan by adding an extra Halls trigger only costs about $20 and not that difficult with proper tools. while you've got beancan torn down, that would be the time to relube mechanical advance.

carrying a spare ignition module takes little space and are not that expensive. then replacing problematic 12v Bosch coil with high performance Dyna coil. for a total cost of about $150, includes spare Halls trigger, new Dyna coil and spare ignition module.

I see no reason to carry parts that have a long history of next to zero failures. or come up with solutions for non-existent problems.

if one was racing, huge advantage with electronic ignition advance of being able to change ignition curves. not so much for adventure riding.

thanks for pointing out full redundancy of twin plug ignitions. would R80G/S gain any performance with it's low stock compression ratio and dual plugs?

_cy_ screwed with this post 10-28-2012 at 02:50 AM
_cy_ is offline   Reply With Quote