SOHC.co.uk Forums > SOHC Singles & Twins
CB200 carb issues
K2-K6:
Certainly an interesting discussion (we should do this as topic I feel as it brings interesting views to consider) that's as opposed to trouble shooting thread.
Hopefully to constructively add something;- the ignition advance doesn't change dwell or compensate for it's shift. Dwell change is because a mechanical system with rotor, although constant geometry, will pass the trigger point faster and faster with increasing revs, and so shorten in time frame the effect of that gemoetry. This has to be accommodated in coil performance if the ignition is to function at both low and high rpm.
It's something that true electronic triggering and accompanying switching eliminates via constant dwell TIME through full rpm range, if designed correctly.
Ignition advance shift is solely to take care of fuel burn characteristics, this is relatively constant and wouldn’t complete at the correct point in power stroke as rpm increaesd (a diesel is like this, and limited generally in max rpm because of it) to get the fuel to reach peak combustion at high rpm at correct position in stroke there's need to start the fire earlier and earlier, hence ignition advance to make sure the burn constant is fulfilled even though the piston is travelling faster.
Johnwebley:
Gentleman, thank you for your input,
This is typical of this forum, lots of intelligent discussion and help,
Great fun reading it,
Ok,the weather has improved, so I shall get the 200 out for a run,
Might even see if it will rev past 6k with no load,
Might get the 500 out, that does rev past 9k,but it has Boyer ignition
Thanks guys,
Sent from my SM-A750FN using Tapatalk
K2-K6:
I do think that Boyer is a really clever system John, and didn't grasp the theory/ strategy of design until looking at diesel injection system (very similar in running retard control rather than advance) in how it works, signalled by correctly checking ultimate timing at full "advance" position to correctly set the baseline.
Johnwebley:
--- Quote from: K2-K6 on March 12, 2023, 11:25:42 AM ---I do think that Boyer is a really clever system John, and didn't grasp the theory/ strategy of design until looking at diesel injection system (very similar in running retard control rather than advance) in how it works, signalled by correctly checking ultimate timing at full "advance" position to correctly set the baseline.
--- End quote ---
I first used Boyer in around 74,on a BSA A65 powered sidecar racer,
then about 78,I got a set for the 500,
Sesman:
Get the 500 out JW. You know it makes sense.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version