Forum

[John L]

Dennis C -
My post was really referring to the misleading info. given in previous posts re points gap and ign. timing.
Al's post immediately before mine revealed that he intended to set the timing by ear/trial, anyway.
My own normal M.O. for timing bikes is to verify (or create) timing marks using a d.t.i. and use a strobe to set the timing dynamically - the only really accurate way to do it.
I doubt very much that Bullet timing needs to be that accurate.........

[another Allan]

.....until you introduce a variable, such as higher compression piston, and then the original factory settings are likely to be incorrect.

[Dennis C]

Another Allan,there is always a variable, that is why the makers figure should only be used as a guide.... As you say, compression, also type of petrol, (is the UK petrol the same as in India, Australia, or other parts of the world?, does it burn faster/slower?), the height above sea level that the bike is used ETC ETC.

[Les H]

I agree with Dennis. The factory setting is of course going to be quite near to the best setting but not exactly. Petrol has changed quite a bit especially nowadays with high percentages of Ethanol added to it. Different fuels, different amounts of carbon build up, different shaped inlet ports (have you seen the original finish of the Indian Inlet ports?) even different styles of riding all effect the optimum ignition setting. Nowadays, engines are produced with far tighter & closer tolerances so the best ignition setting is also far tighter and less likely to differ from a set figure. Most modern car electronic system use a knock sensor that takes the timing just below the point of knocking so the engine is always running at best efficiency and before that, distributers on cars had a "Micro Adjustment" feature that allowed the owner to fine tune the ignition to just below pinking. Certainly if the recommended timing is adhered to the engine will probably run at more than 90% efficiency at worst, but it is quite easy to get it to run just that bit better by fine tuning. I also agree that using a strobe on an accurately set timing mark is far better than trying to set the ignition with a rod in the plug hole and a cigarette paper in the point’s gap. However using a dial gauge and a torch bulb across the pints is a very close second...but then again with all that care and accuracy in the world, you are still setting it to the nominal setting and not necessarily the best setting!

[Norm]

Dennis,
Petrols must vary quite a bit because out here petrol can sit for years and doesn't appear to deterioate. I know in the States they seem to have their petrol left in carbs turn to varnish if left over winter if they don't drain them before they lay them up. Here we wouldn't even think about it. 2 years and I wouldn't think about needing fresh fuel to get a bike started, I might if I had problems getting it going but it wouldn't be the first thing I would think about

[simon]

Things may have changed Norm but I once spent the best part of a day kicking over my Benelli 650 Tornardo that I had left under my mother in laws house in the Blue Mountains for a year or so before I finally clicked that the fuel in the bowls wouldn't even light with a match. As for the the 12 thou points gap I did admit that I don't have any battery and coil bikes in my current collection and the mags are recommended at12 thou gap.

[stinkwheel]

Lest you get totally lost in the details.

If it starts easily without spitting back and doesn't pink at high revs, the timing is correct, regardless of what your dial guage/angle indicator tells you. They are unecessary fripperies other than to get you into the right "ball park".

For best performance, get it doing this, mark that point, then gradually nudge it more and more advanced until it either wont start or pinks, then knock it back to the previous most advanced position.

[Chris]

Is that Fleet Air Arm Al? If it is, I saw your photograph on the Wall of Fame again this afternoon.