Nicely put Peter, but if the information on the BT-H is not available I would need a lot more knowledge of electronic ignition than I have to try to fathom it out.
E: Engine BTH magneto
- Thread starter Sakura
- Start date
One thing I don't understand and neither does the current owner of BTH magnetos is why the single plug and twin plug magnetos available have the same advance curves. What might be fine for the single plug version is or should not be the same for the twin plug which should run far less range of advance. I spoke to the owner of the business and he had no idea what i was talking about..............Could have been my half Kiwi half Aussie accent I guess.
Must admit when I went from twin plug (methanol) to twin plug petrol and then single plug I did wonder about that curve but could never detect any difference on petrol on the rolling road.
The original BTH owner did tell me 2 seasons on methanol and the mag would need looking at as it was under strain at those compression ratios and he was right
The original BTH owner did tell me 2 seasons on methanol and the mag would need looking at as it was under strain at those compression ratios and he was right
I have met Peter who now owns BT-H a few times. He seems a really nice guy. (Just my own opinion.)
He is not a motorcyclist or an automotive engineer, nor does he claim to be. He just gets the parts made to the drawings and assembles them to earn a living.
The unit he makes seems to generally work very well for most standard old bikes applications. The electronic advance range is similar to the range one would get from the original mechanical auto advance. It works well for most standard old bikes that had a magneto with a mechanical auto advance.
If you want a smaller range with a mechanical advance you can modify the stops on the unit as some readers of this forum have done. If someone wants a different electronic advance range then that would require a redesign of the circuit, something that most of our readers would not be able to do. It is also unlikely that Peter would do it either as it would mean paying someone to design, make and test a new circuit. It would unlikely be viable from a business point of view for the few modified units he might sell.
I have no financial interest in the BT-H business but have used one of their units on my Rapide since 2008. I did have some (very) small input with the original owner who set up a new business and spent a lot of time without income while he designed, prototyped and tested to produce a unit he could sell.
I think that there are probably several electronic units available that may offer the ability to reduce or increase the amount of advance available. I can't comment on these as I have not used one.
The part that surprised me most was that Peter said that around 50% of the mags he sells are for twin plug head engines and that no one else had complained.................
Very strange
In my case it was simply a case of connecting or disconnecting one of the coils there were no changes to the mag itself
to recap I bought a BTH mag (Comet) for our racer used it as a single for 2 years added a second plug for 3 seasons now back as a single plug for years all done with discussions with original BTH owner/maker just plug un plug extra coil in series.
Did the new owner mean he sold 50% of his BTH with two coils? sensible to have a spare
In my case it was simply a case of connecting or disconnecting one of the coils there were no changes to the mag itself
to recap I bought a BTH mag (Comet) for our racer used it as a single for 2 years added a second plug for 3 seasons now back as a single plug for years all done with discussions with original BTH owner/maker just plug un plug extra coil in series.
Did the new owner mean he sold 50% of his BTH with two coils? sensible to have a spare
My understanding was they were for twin plugs per cylinder.............Maybe I was more confused than him.
I think the best solution is electronic ignitions that are programable by the owner and available in single and twin plugs per cylinder. These are difficult to find in ready to use on Vincent configurations. OldHaven has been posting about the one he is working on for the twin made by Power Arc. Power Arc has no easy way to do a 50 degree ignition, so they have been slowed by the redesign. Programable ignitions for the single have always been available, but you had to supply your own housing. I think that Ron may have solved this problem with a supply of ignition housings, but he has been waiting on the twin ignition simply to keep the pressure on the company to complete the development of the 50 degree ignition.
David
David