More on V50 II Ignition

Well I bit the bullet and ordered a Silent Hektik ignition system. It wasn’t cheap :frowning: ! I ordered it from their German website, which is almost entirely in German, making it tricky as my German vocabulary is very small! It arrived incredibly quickly - I ordered on Sunday and it was delivered on Tuesday.

The installation instructions are not great and don’t mention or cover the V50, though I think it would work fine with any Bosch alternator bike. Everything fitted perfectly and the bottom line is that the flat spot is completely cured and the bike seems to have more grunt at low revs - in short I’m very pleased with it, or I will be when I get over paying for it!

If anyone else is contemplating this upgrade, let me know here and I’ll post some notes on installation - some vital clues are missing from the instructions! I will also share my recommendations for locating the components. All the parts are top quality and in my view, the Silent Hektik coils are worth paying the extra for, they have massive iron cores compared with the original Nippondenso coils and they produce the biggest sparks I’ve ever seen. For installation you definitely need a strobe and some accurate means of finding tdc - I used a dial gauge. I haven’t experimented with the range of advance curves available, but curve 9 definitely works well for this bike.

Regards, Joe.

If you use Google Chrome as you browser you can right click at the top of the page and select “convert to English” alternatively copy and paste the text into Bablefish or any other online translator. I hope this helps. Glad the ignition gave a good result :smiley:

Thanks for the update. Can’t remember what curve I set mine to and the box is mounted on a fabricated plate under the tank. Interesting about the coils as I am using non SH.

I’ll never know if I made the right choice of coils for sure. The only specification they give is a dc resistance of 2 to 3 ohms. My original coils measured 3.6 and 4.3 ohms. A bit of research on the net showed plenty of cheapo coils at around £20 each and quality coils from £50 upwards. There is a vague mention that spark duration and timing can only be guaranteed with the SH coils, which I thought might indicate that other coil properties such as inductance may be important and since the SH coils come out at around £45 each (not cheap), there wasn’t a lot to be saved anyway unless I tried to use the original coils. I don’t think this is a CDI system, I don’t remember seeing any big enough capacitors when I had the lid off the box.

On my bike the original master cylinder for the front brake, normally located under the tank, has been replaced by one on the handlebar, so that’s where I put the SH Box.



Since fitting a replacement (std) Bosch ign unit to mine it has been very much a case of ‘what, flat as your hat? - no flatter than that’. I don’t understand why that swap out should have caused this but it has left me open to persuasion to swapping out the OE kit and your initial post here has possibly tipped the balance (though I’ve just checked pricing - ouch).

Any other observations you have on install and set up would me very welcome.



I’ll dig out some pictures over the weekend of the fitting I made. Hopefully of some use!

Sure I’ve mentioned this before but you have to very careful measuring low resistances, apart from the accuracy of the meter, the slightest bit of tarnish on the probes and/or the contacts of what you’re measuring will add extra resistance. Friend of mine who is a electronics technician once told me that they file their meter probes to sharp points which can then penetrate the oxide layer or dirt on the surfaces of what they’re trying to measure the resistance of.

So your 3.6 Ohms could well include 0.6 Ohms of “dirt”.


If you have previously fitted electronic ignition to a classic bike, the usual thing is to make the static setting at maximum advance and the box of tricks retards according to revs. The Silent Hektik (SH) is different, you set it at the idle advance point. Looking at the advance curve in the V50 manual, it’s not very helpful, it shows zero degrees up to 220rpm, then the advance goes vertical to 13 degrees at 220rpm and stays at 13 deg right up to 2000rpm. Mine didn’t start advancing until almost 2500.

I started by marking TDC on the starter ring for the R/H cylinder, then I counted back 4deg per tooth and marked 8 deg BTDC. It took me a bit of faffing about to establish 8 deg, but hopefully you can use this figure and be right first time. I removed the alternator stator and rotor and removed the old pickup coils and wiring. You need to replace the rotor and torque it down securely, before removing the fixing bolt again. You don’t want the rotor to move at all when you are trying to set the timing. In fact I used a small electric impact driver. So, set the crank at 8 deg BTDC on the R/H cylinder and fit the ignition rotor and pickup as shown in the instructions.

I fitted the box under the tank in the space where the front brake master cylinder used to be and after a lot of fiddling I managed to fit the new coils into the space where the old coils used to be. They are fatter though and it was a tight squeeze. If I was doing it again, I’d fit the box where the old coils were, and put the new coils under the side panels, where the old ignition boxes were.

The bike started immediately (sigh of relief) and I put the strobe on the R/H plug. I set it so that the advance stopped at 34 deg BTDC and that was at around 4000 rpm. At idle, it was showing about 10 to 12 deg BTDC. All this added up to a static setting of 8 deg BTDC. If you decide to go ahead with this, I would be most interested to hear if you agree with the 8 deg! At the very worst, it’ll be a good starting point. I chose curve 9 on the switch setting - I must admit it’s early days yet, but it seems good so far. And the bike is so much easier at low speed - of course that is based on very brief experience and a sample size of one!

I hope that’s helpful. You can see the SH instructions here:

Good luck!


Yes, I quite agree with this and having spent the early years of my working life fighting with contact resistance in telephone exchange equipment it is an old friend/enemy! The two SH coils measured 2.5 ohms each and I got consistent readings from them. The old coils were not very consistent and they were different to each other. I’m not sure that I would recommend filing meter probes because it would remove the plating which may well swap one problem for another, but certainly you need to make sure it’s all clean and you have plenty of pressure on the contact point. A tricky measurement for sure.

Incidentally, the Nippondenso coils have the “Japanese Style” bullet connectors on them. These look pretty cheap and nasty, but I have to admit that they have stayed remarkably clean and free from corrosion. I’m grudgingly impressed!

Thanks for taking the time to write that up – much appreciated.

I’m fairly deeply in the mire bike spending wise at the moment, and my Veefer is my main winter ride so I’ll defer for the moment, but reckon I might pick up on this come the spring … depending on what else I’ve broken by then.