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4 stroke, single cylinder (lifan?) 200cc
What do I set the new electronic tacho for, one spark per cycle, one per two cycles or two sparks per cycle? I always thought it was one per but after reading up, I am confused! Suck squeeze bang blow?
If no-one knows and I have to set it up the backwards way, by looking at the revs indicated at top cruising speed, what should it be showing? 8000 or so?
Your first answer will come from someone who knows feck-all about engines, but if engines make any sense then it should be one spark per cycle, meaning one spark per two revs.
Lifan vs Loncin :naughty:
http://www.miniriders.com.au/tech-ta...-engine-3.html
Kinlon is Loncin's product | http://www.catarc.org.cn/vin/WMIVIN.htm LLC = made in Chongqing | LVJ = made in GuangdongQuote:
Originally Posted by jape
Youtube had some video about Loncin in CQ | Loncin in GD http://motorcycle.sh.cn/viewthread.p...d=86471&page=2
More experienced wrenches please weigh in on the matter but from what I understand a single cylinder engine can have one or two sparks per cycle depending on the spark box configuration. The reason for the one spark per cycle setting is so universal gauges can be used on some twin cylinder 4 strokes where both cylinders share a coil. This means the coil sparks twice so each cylinder would get a proper detonation but, at the same time, there's a "wasted spark" on the exhausting cylinder. The wasted spark may also burn any residual fuel in the cycle but don't quote me on that.
Why would a single cylinder have it? Probably economic reasons more than anything else. Either way, I'd set your unit to 2 PPC (pulse per cycle) as this will probably be more accurate. I don't think you should have a one spark per two cycles option unless it was perhaps a 4 cylinders that all shared one coil... but at that point, I'd guess you'd have multiple coils. Or perhaps a twin with 2 plugs/cyl?
CC
Well it does have the three options CC! And I must have read the same as you because that is how I got confused ... set on the 'one per cycle', it shows 1100 revs at idle. I will have to take it out on the road later and see what it shows in normal running and work it back from there. Dunno if I am getting old or what but everything seems to be harder to work out these days.
Humanbeing, thanks for that post, always interesting - it seems I have a good engine then - do you know how this should be set? I could of course take the plug out and watch the spark as I turn it over slowly by hand if I was thinking clearly but my logic centres are down this morning, having given up smoking and cut back on coffee, on doctor's orders. Bastards really ruin life given half a chance, never should have gone to see them.