Nowt wrong with solid-state, I am still using the germanium power amp. I’m a silly plonker I keep forgetting there is positive feedback between Q1 & Q2, by R7 & C5, this greatly sharpens up the switching speed from one state to the other, so it is impossible for there to be any ‘in between’. Main reason why C7 cannot affect timing (another is that Q1 turns on too fast anyway). So still can’t see what C7 etc. does, it isn’t rev limiting I tried increasing the ‘speed’ (‘20,000 rpm’ for a 4-cyl engine), bugger all any difference, still made ‘sparks’. [quote]C2 discharges through Q1 while it is on until it turns off again which turns off Q2 which turns on Q3 and re-energises the coils. Not 100% sure on that but I’m living with it for now[/quote] No R5 & C2 are just a supply filter to exclude interference type noise from the supply line for Q1 etc. In sim the Voltage hardly changes, although it does slightly. Q1 & Q2 are turned off when the input pulse falls to zero. [quote]Q1 seems to be triggered on by a differential voltage between sig+ and sig-. Not sure how exactly but instinct tells me it’s something to do with reaching a diode forward voltage threshold and causing a voltage across R2.[/quote] Correct. Shape as per Gunk’s drawing.
Example plots from the simulation:
Mike H2014-10-11 16:56:44
Lucas Rita is fine for Monzas. I have it fitted to mine, no probs. The key thing is to strobe it at 7,000 rpm and ensure it hits full advance.
hook-nose hicks2013-10-11 21:53:49
I think this is the thing.
Yes…hitting full-advance is the key. Everything else is a minor irrelevance / side-issue / distraction.
Yesterday I was playing with this - assuming drawing is even vaguely accurate, top one shows gap between tip and pick-up pole at full advance, there’s a 5mm wide metal tool to set this at the full advance angle BTDC. I was then curious how far rotor needs to be rotated to bring tip up to pole piece, turned out to 18 degrees, x 2 = 36 degrees of crank. 32 degrees would then be just in front of, instead of lines up with, not sure where mine is at the mo. As I say it assumes drawing is anything like accurate to real life.
Mike H2014-10-11 16:55:05
Generally speaking, pretty accurate.
Only IF drawing is accurate. Or it may all be rowlocks…
That is the ORIGINAL drawing, believe me.
Sure it is, you misunderstand me, I mean how accurate is it if you compare it against the actual real metal articles. I mean it’s not an engineers blueprint.
Ah, see what you mean there…not sure now.
Only one way to find out of course … Anyway mine is up the spout somewhere and I now think is deffo retarded, this explains barking exhaust @ >= 4,000 rpm, (gas still burning while going down pipe), struggles to pass around 80 mph and, I just realised yesterday, why it’s sometimes a struggle to pull away from a standstill without stalling it as well so it’s obviously retarded at idle as well, looks like. It’s all starting to make sense …
Mike H2014-10-11 17:03:01
Strobe it at 7,000+ rpm. You owe it to your neighbours! Just ensure it hits full advance. I think there is a mark on the clutch basket / ring gear.
I found full advance on my 750 virtually impossible to find with a strobe so had to make a near guess - wasn’t keen at revving it to 7,000 rpm under no load whatsover.
For a short time, it won’t hurt it at all. Use a battery-assisted xenon strobe.
In most cases full advance is applied at 5k rpm, no need to go up to 7k.
Yes I would have thought so too. If not 4k
Sounds better at 7,000 though!
On my Monza the TDC mark was a line on the outside edge of the flywheel, there was a centre punch mark at 10deg BTDC and a line on the face of the flywheel at max advance. This was different from some of the literature so might be a useful reference in case yours is the same. I used different coloured paint to highlight each mark as they can be difficult to see due to timing chain jitter at higher engine speeds.
That’s true, especially through black Lafranconis…