ignition timing

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volroom

Race Dog
Joined
Jun 15, 2011
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Location
Abu Dhabi
Bike
BMW R1150GS
Read this: https://advrider.com/forums/showthread.php?t=79207
Thought I'd give it a try in my quest for more torque, and I'm very happy I tried it. With low compression (relatively low) motors like the GS, the flame front spreads slower during power stroke. At high RPM the piston can run away from the flame front that starts at the spark plug electrode (if no pinging occurs)..which is a problem since the expanding gas is supposed to push the piston. Electronic ignition adjusts the ignition timing, but there's a way to advance it slightly on these bikes. Basically, just shift the Hall sensor plate behind the crank pulley to the right (if you are looking towards the rear end of the bike). Loosen the screws of the HES plate , and move the plate using a flat screw driver.

There's definitely a change! Awesome, cost me nothing. I advanced it to the max, what I found is the midrange is improved, but pulling away in first is a bit weaker. This can be explained because at really low RPM (like idle), the pistons are moving relatively slowly, so if the gas is ignited before TDC, the flame spreads fast enough to actually push against the pistons as it is trying to compress the gas. So, I will retard it slightly.it's a 20min job..you can play around and find where the motor makes the most power, but this will be where the ignition timing is slightly advanced. Disclaimer: I have made some slight mods, so my results might be due to a combination of things.
 

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