Ignition Timing & modern Fuel

Howard

Howard

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http://www.norbsa02.freeuk.com/goffypazon.htm

I was under the impression this was the curve on my Surefire for a twin (from Kirby Rowbottom). It certainly feels like a smooth curve, and it's changed the engine characteristics completely from the old bob weights. I'm not sure why a Comet would have steps in the "curve".

My one grouse is that it either runs at 50 degrees BTDC, or the red spot is in the wrong place and setting the timing has been a nightmare because there's no other indicator - but well worth it now.

H
 
alscomet

alscomet

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Glen,Going back to the degrees BTDC topic,I had some really good advice and bought one of those fangled lights which show you when the points are just opening cost about 40 earth pounds. While I was setting up my comet I deceided to see if there was a difference between using a piece of fag paper and the light and I could easily get 2 degrees difference either way with the fag paper compared to the light so its possible that using the paper could have an effect either way on your
firing point. Alan
 
B

Black Flash

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Hello Bruce,
I have yet to see the first heatshrink to wear through. I mean it will only get compressed or squashed lightly, so I really cannot see the heat shrink wear. But as I said it was just my opinion.
Regarding Martyn answer.
I am aware that this plastic falling off could create a very big problem, but so can a metal ear breaking of and getting munched in the timing gear. I will never forget finding the needle roller from the valve lifter next to the half time pinion in the timing chest, it send my pulse skyhigh!
this could have easily been the most expensive needle roller money can buy.
I believe that even ATD tuning can become a wonderful part of Vincenteering. you ask 20 people and get 25 opinions, but isn't this what it is all about.

Regarding electronic ignitions. I have a 600 cc Terry Price twin plug topend kit on my Comet and the engine start and runs beautifully on a boyer system. I cannot say anything about power figures as it is not yet run in, due to German TÜV (MOT) reasons. The engine is timed at 28 ° full advance has great power and is a joy to start first kick everytime.
Bernd
 
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Magnetoman

Magnetoman

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alscomet said:
Bruce I bought mine from these people.http://www.themagnetoguys.co.uk/page008.html. I shared the cost with a friend its something you only use once in a while...
Click to expand...
If you can live without the sound of the buzzing (and you just might find it easier to live without it than with it), a cheap LCR meter will do the job just as well while also being something you can use all the time rather than only once in a while. These magneto timing boxes just LC resonant circuits using the fact the inductance of the primary changes by a factor of ~10x when the points open. An appropriate size capacitor is used to give a tone in the audible frequency range. If you search ebay for 'LCR meter' you will find ones for less than $15 delivered to your house. Use the inductance scale, set it so it gives a reading when the points are closed, and that reading will change significantly the moment they open.
 
C

chankly bore

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"Tuning for Speed" page 156, fifth edition. Very sophisticated static timing device shown. with a bit of nadgery you use the bike's own battery and the bulb from the speedometer. cost: one pair of crocodile clips, or in Florida, alligator clips, plus about five feet of old wire from your last rebuild. Why do all you blokes want to spend money unnecessarily? Perhaps we could have yellow shrink wrap for camshaft failure and red for big-end?
 
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