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Ulis electronic ignition conversion

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skyler.robbins
Posts: 227
Joined: Sat Sep 22, 2018 4:14 pm

Ulis electronic ignition conversion

Post by skyler.robbins »

Hey All,
Questions about the Ulis electronic ignition.. this one..

https://www.ulismotorradladen.de/articl ... -R691.aspx

I’m not seeing if you retain your original 6 volts?
Do you keep the existing “No resistance” plug wires?
I’m assuming you need to have the battery to start the bike?

I really want to keep my points system, but I have .003 run out on the end of the cam nose.. which although seems minimal, once everything is attached, the run out is more like .006 at the end of the advancer.

The bike isn’t in running condition yet.. once it is, I’ll use the strobe to check the timing to see if it’s all a nothing burger..

But until then.. curious if anyone is running the Ulis system?

1967 R502
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Re: Ulis electronic ignition conversion

Post by 1967 R502 »

I’m looking at this one as well, it does not say if you are retaining 6V or not. Because you are replacing the voltage regulator it may be the case that it steps up to 12v

However Uli’s has a very helpful staff. Why not ask?

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skyler.robbins
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Re: Ulis electronic ignition conversion

Post by skyler.robbins »

Hey,
I did send an email and that got back to me.. it does retain the 6 volts.
I like this one for the simple install.
I “think” I’m going to need it due to my camshaft having .003 run out.. which ends up being around .006 after the mag rotor and advancer unit is installed.
Still working on other things.. I’ll know more when the bike is running and I can check timing better.

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wa1nca
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Re: Ulis electronic ignition conversion

Post by wa1nca »

Yes get it running and check differential timing
Tommy Byrnes
54 R51/3, 55 R50/Velorex 560 sidecar, 64 R27, 68 R69US, 75 R75/6
Ashfield, Ma
USA

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skyler.robbins
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Re: Ulis electronic ignition conversion

Post by skyler.robbins »

So far with static timing, it’s bad… one side is on the “S” line perfect.. rotate it 360 and the other side is just below the “OT” line.. ouch.

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niall4473
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Re: Ulis electronic ignition conversion

Post by niall4473 »

IMHO the flywheel timing marks are a guide only, the flywheels can shift in service, and were marked on an individual engine after building, so if a flywheel is fitted to a different crankshaft it would be pure good luck if the marks are correct.
Unless the engine is a known quantity, I set up a degree disc using the 'plug-stop' method and find out exactly where the flywheel marks are in degrees BTDC, and make additional marks if necessary before attempting any ignition set-up.
Oil is always cheaper than metal

Seek
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Re: Ulis electronic ignition conversion

Post by Seek »

Maybe on English bikes, but on the BMW's the flywheel is fixed with a woodruf key! And all the flywheels have the exact same marks relative to the keyway. If the flywheel shifted some major bad thing happened and the key probably sheared off. So, on an unkown bike it is a good idea to cheack the TDC mark on the flywheel. When it's off, you should pull the gearbos and clutch and check what's wrong.

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skyler.robbins
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Re: Ulis electronic ignition conversion

Post by skyler.robbins »

I did confirm the TDC using a TDC tool and it matched up perfect with the OT mark on flywheel.
I also tried the Duane Ausherman technique of tapping the mag rotor in the opposite direction of widest opening of points.. no luck.

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niall4473
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Re: Ulis electronic ignition conversion

Post by niall4473 »

Seek, the flywheels do not have 'the exact same marks' because no two things made by human beings or nature are exactly the same, that is why we have manufacturing tolerances, in this case in the flywheel, the crankshaft and the Woodruff Key itself, on the key the tolerance will be dimensional only (about +0/- 0.125mm), on the flywheel and the crankshaft there will be an angular tolerance also.
With the exception of the R68 and R69 engines, which were hand-built and very carefully selectively assembled by skilled fitters, these bikes were assembled by semi-skilled production line workers.
At the workstation where the flywheels were put on, the guy or lady doing the job would have a bin full of flywheels, a box of keys ,a box of bolts and one of lock-washers, as an engine arrived they would grab one of each and assemble it. They had to fit together, so the tolerances would be sized such that they went together whether they were all at minimum or maximum metal condition, because there was no time for the worker to mess about trying different parts, a friend of my Dads did this job on Leyland 'bus engines, job, he had massive arms and shoulders from lifting all those flywheels. On top of all this, there would be a minimum clearance for the fit of the Woodruff key in both the crankshaft and flywheel, because the key could not be allowed to impinge on the fit of the flywheel on the crankshaft taper, because it is the taper fit which drives the bike, not the Woodruff Key, which is neither capable nor intended to do it.
When you add all these together, there is quite a scope for variation, then you send your crankshaft away for rebuild, which itself is subject to tolerance, and you get an exchange one, which started life in a different engine, this used to be very common because people needed their bike back on the road quickly so that they could get to work of a day, and you multiply that scope by an order of magnitude.
I promise you, I have seen Woodruff keys with a clear ridge on them, not wear as such, more distortion, the cranks themselves actually flex in service, that is why the R69S had to have a torsion damper fitted to absorb the torque, without which the flywheel is quite capable of snapping the rear half-shaft like a carrot, I know, I have had it happen.
Trust me, these marks are quite often far enough out to affect the timing, and should be regarded as a starting point, near enough to get the bike running, after which it should be fine-tuned by some other method.
Oil is always cheaper than metal

Seek
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Re: Ulis electronic ignition conversion

Post by Seek »

Well, I think you are underestimating the precision of BMW's manufaturing. Much was allready automated, mechanicaly of course, no computers back then. I certainly meassured my engines, and they were spot on! Also, I have never heard about flywheels being individually marked, you can swap them around no problem.

And don't forget, it is not the woodruff key keeping the flywheel in place. It is only for positioning during assembly. it is the taperfit that keeps the flywheel where it should be.

Still, I do agree with you that it is a good idea to meassure the correct position of the OT mark on the flywheel. There have been some variations in timing over the years. Also someone might have made a mistake during assembly. When your woodruff key is sticking out too far, the flywheel taper can't seat properly and shit can happen. Or the taper fit was bad and the flywheel shifted, shearing of the woodruff key.

But my experience is not that extensive. How about asking the group. Did somebody ever find an OT mark (TDC) shifted in their engine and what was the reason?

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