Just put Wassell ignition on my B25 Starfire. Seems to work fine, but I have a question about ignition timing.
The last instruction in the installation booklet tells you to start the bike and rev it up to 4-5000 rpm an adjust to match the marks.
Question is how could anything change from static since the mechanical advance is no longer there and everything is screwed down tight?
Scratching my head on that one.
Any thoughts?
Thanks.
Just about all timing instructions have this for using a strobe for getting the advance absolutely spot on. Static timing using marks and measurements can still have an error. However, that error may only affect the running of the engine at high revs hence 4 - 5000rpm. It is till dependant on the chosen marker being absolutely spot on.
I personally find it a bit unnerving revving a stationary bike to these sort of revs and general pay a lot of attention to getting the static timing right. If the bike runs well then it should be fine or a minute tweak of the timing will sort it out.
Dave.
The issue with electronic is establishing the exact firing point. Easy with points it is when the are just opening not so easy with electronic as there may be slight variations between units. The strobe timing ensures that the timing is set at the correct figure when at full advance which is where most of the running will happen.
With electronic on my A10 rather than set it at a set rpm figure I rev it until the timing stops advancing, about 3000 rpm with the Boyer setup.
The EI unit is programmed to fire at a certain point BTDC just like the points would. So you set the EI unit up the same way. 1st on static to get it running, then dial it in with the strobe so its bob on. Just like you would with points.
Advantage is stronger spark. Fewer components and crucially no moving parts so no wear.
If it does need to be adjusted when you strobe it, you loosen the two small screws that hold the electronic unit into the casing so you can rotate it a smidge.
Tighten the screws up. cover on, and you'll probably never touch it again.
Having read through the Boyer instructions but not fitted it yet, I too wondered how, if the advance weights etc are removed, does the timing advance itself as the revs increase as everything is screwed down tight, as said.
The advance is electronically controlled in the black box, I presume, to a preprogrammed curve to suit the bike/engine to which it is fitted.
The Boyer is certainly only set at the static timing point, and that's it, so the advance must be controlled by the electronics.
Yes. The advance is electronically controlled in the black box. It reads the engine speed and position by the spinning magnet.
I would imagine strobing the engine after fitting always a good idea as most if the engine use will be on full advance. Dynamic timing is always more accurate as it will pick up any minuscule error in the static timing.
Try it and see. Be interesting to see. My wassell system needed a tiny adjustment to get it spot on.
Just re-reading the original post and thought it might be worth mentioning that 'checking the marks' at 4-5000 RPM refers to using the bike's dynamic timing mark - if it has one - or using a degree disc if it doesn't. (I don't have my Rupert Ratio book to hand to check wha the B25 has.)
It doesn't mean strobing against the static timing marks on the EE unit....
Apologies if that was stating the obvious but thought it worth mentioning.
Cheers,
Bernie