Vintage BMW Motorcycle Owners

After going through Vech's article - http://www.benchmarkworks.com/articles/ ... start.html
And testing exactly as he describes, and after reading lots and lots of other articles on the web including the excellent stuff that Duane Ausherman is explaining, I now understand that this is my situ on the R51/3, unfortunately.
This explains why one cylinder is working very hot while the other gets fuel and a spark but is dragging behind and why I could not set the ignition to both sides, no matter what I tried and how.

Vech mentions that "this can be easily corrected by buying a electronic, magnetic, inductive ignition system, like a Dyna III, in which a rotating magnet is mounted to the old, worn out advance".

So I am on the way now to purchase an electronic system and am currently examining the system offered by Vape - https://www.vape.eu/en_US/en/bmw-r50-r5 ... crankshaft

Will this system be any good in a differential timing situation (Lets put a side the generator that is also provided in the kit but is of course another system)?

Let's assume, hypothetically, that I also have a runout camshaft. Will these systems overcome it and still provide a solution?
It is possible but I did not measure it as I do not have a gauge to do it.

Thanks a lot for any help.

Have you had a chance to use a timing light and visualize the amount of differential timing? I had differential timing on my R69S and I was able to eliminate it after talking to Richard at Bench Mark Works. I discussed this in my thread on chasing down the rough running on my R69S in this thread:

viewtopic.php?p=76935#p76935

It didn't solve my problem...next I attack the carbs to resolve the pinging issue. But I did notice that the bike ran much smoother at idle. It was quite evident.

Differential timing is not that hard to correct. Just takes a little will-power to whack the end of the cam. I've done it with excellent results on both of mine.

Dave

I had put it off for so long because I thought I actually had to hit the end of the cam. In reality, you're hitting the bolt head that holds the advance unit on the end of the cam. What you're doing is adjusting the advance unit where it sits on the end of the cam.

Micha wrote: ↑

Sat May 08, 2021 5:11 am

After going through Vech's article - http://www.benchmarkworks.com/articles/ ... start.html
And testing exactly as he describes, and after reading lots and lots of other articles on the web including the excellent stuff that Duane Ausherman is explaining, I now understand that this is my situ on the R51/3, unfortunately.
This explains why one cylinder is working very hot while the other gets fuel and a spark but is dragging behind and why I could not set the ignition to both sides, no matter what I tried and how.

Vech mentions that "this can be easily corrected by buying a electronic, magnetic, inductive ignition system, like a Dyna III, in which a rotating magnet is mounted to the old, worn out advance".

So I am on the way now to purchase an electronic system and am currently examining the system offered by Vape - https://www.vape.eu/en_US/en/bmw-r50-r5 ... crankshaft

Will this system be any good in a differential timing situation (Lets put a side the generator that is also provided in the kit but is of course another system)?

Let's assume, hypothetically, that I also have a runout camshaft. Will these systems overcome it and still provide a solution?
It is possible but I did not measure it as I do not have a gauge to do it.

Thanks a lot for any help.

The Vape system is triggered off the crankshaft and uses only one trigger so their is no differential timing
Tommy

Thanks Tommy!

The Vape system (formerly known as Powerdynamo) made good economic sense for me.
Enough of the original components in the ignition and charging systems had reached, or were near enough, their sell by date, so that economy drove my decision.
Plus the usefulness of both 12 volt lighting and electronic ignition have been well proven to me since their introductions in the automotive world years ago.

The first Powerdynamo system I acquired was cam triggered, but by the time it actually arrived the crank triggered version had just been released, and so the earlier version was exchanged for the latter.
My reasoning was that when kickstarting the engine, the ignition sensor must acquire crank location and rpm, meaning the crank must roll over several times to trigger the sensor multiple times in order to acquire a valid signal.
But if the sensor was located on the cam, then the sensor has just half the chances to acquire this information, and therefore the crank needed to rotate twice as many times to equal the sensing capability coming from the crank location.
This is perhaps the reason the system is not recommended for use with a lightened flywheel; not enough rotating mass to facilitate sufficient signals from the sensor.
(unless you've the thighs of Berthold)
(any Baron Munchausen fans out there?)

Anyway, in your situation, Michael, the cam nose/advance unit is no longer relevant as the advance unit is eliminated, its job is now being done electronically, rather than mechanically, with the electronic ignition.
Best-
George

And if you do decide to proceed with the electronic magneto, be sure you're ordering the kit for the 17mm crank nose, if the motor is original to your bike, rather than the 20mm version for the later /2s.
Best-
George

Thanks a lot to all of you.