ignition units

hi all

i have been reading on the sabmag site about the vf1000 ignition units as mine failed, i managed to repair mine but would like a look at a vf1000r ignition unit as it lets the bike rev higher ( i have a “r” engine in my vf1000fe). does anybody have a broken “r” ignition i could look at? if i can get one i should be able to see what the difference is and may be able to offer a repair service for them in the future.



I have a set that came with an R motor we bought a while back.The previous owner must have been curious as to the contents of these little black boxes as he has opened both.Send me an address and I will get them off to you,these units are getting harder to find so we would be very interested in a repair service for them.Regards BIF


i have emailed my address to you. these are a very simple ignition and i can see no reason why i wont be able to fix them. the version i have is a single unit, are the ones you are sending the the twin ones? if so do you know if they will work on a wiring harness designed for the single. if not it should be easy to make an adapter cable. also do you know if they work?



Twin units used in Fe need a Fe starter clutch. The single units used in Ff, Fg, F2f, F2g, Rf and Rg need their own starter clutch. There is difference in trigger time, maybe timing also. I do not have partsguide for Re, so I do not know about their igniters, if they were done with single or two units.

I replaced the transistors and capacitors in some units, bought them from RS components, fast switching automotive transistors, they worked ok, I never got around to learning how to test TCI CDI TDI units without having a the relevant bike to check them on.

Not sure if they work or not and they ar from an RE so are twin units.I do have a spare for the Bol which came from an R but it is the back up for two bikes so would rather it stayed on the shelf.BIF

not a problem, don’t send me anything you need as a backup only the RE ones. i have been building a test rig in work and am nearly finished, i should be able to determine the amount of advance the ignition is running at any given revs, this will enable me to identify any differences between the boxes. if they dont work it will give me the oportunity to fault find on them which always helps to increase understanding of how they work. i am hoping that honda erred on the side of caution with these boxes or even set them so the bike would pass emission tests ( as most 80’s japanese bikes were ) this would allow them to be tweeked to improve power delivery. no guarantees but if you dont try you can’t succeed. i will return the boxes to you as soon as i have mapped them. thanks.


Hi Gary, just checking that you are talking about the spark units mounted in the tail? If so, I have a problem with one and would be interested to hear what can be done with them. Aftermarket ones available?

hi manwell. yes it is the spark unit in the tail piece. what type of unit do you have a single box or a twin box? also what is the problem you are having? there are two main symptoms loosing two cylinders and the tacho or two cylinders and the fuel pump stopping. the single box seems the easiest to repair, i have finished building the test rig and repaired two units, one had failed on the fuel pump and the other had an intermittent problem on the tacho side. all i had to do was re solder all the joints where the wires for the coils, pickups and power are attached to the board. i would try this before thinking of getting a replacement. as for an aftermarket ignition there are several adjustable ignitions on the market but you would have to set it up on a dyno. when i get time i want to convert my spare ignition to an adjustable one and put it on a dyno, will let you know how i get on, in the process of fitting vfr750 swing arm at the moment so it may have to wait till i have finished that.


Hi Gary, I’ve got another problem with the bike not firing on the back two cylinders and the tacho not working. No spark to the plugs on the rear cylinders. Tried changing coils and Spark Units but no joy so far. What do you reckon?

Forgot to mention, mine is a VF1000F with two Spark units. Would it go better with VF1000R Spark Units? I’ve got a VF1000R motor in it.

hi manwell, it could be the pulse generators, or a broken wire in the wiring loom

If the tacho WAS working, you could try flicking the glass hard on the gauge - works on my FII everytime anyway [:)]

Thanks for the info guys, it can’t be too hard to trace can it?

hi manwell, i agree with vf pete sounds like the pulse generators, you can test the generators with a test meter they should be 470 ohms, measure between the white and yellow wires for 1 and 3 cylinders and white and blue for 2 and 4. easiest place to do this is in the plug. my bike stated doing this last year but it was intermittent so hard to trace, finally traced to pulse generators. i also have VF1000R engine in my VF1000F, the VF1000R spark units let the engine rev higher not sure by how much. the spark unit on the F is totally different internally from the R so there may be other benefits from fitting an R unit. good luck.

I’m getting 511 ohms resistance on one pulse generator, and 521 ohms on the other. They are supposed to be around 480 ohms - what does that tell you?

Hi Manwell, was the VF hot or cold when you first had the problem?
pulse generators can show the correct reading when cold, once the engine warms through the pulse generators fail usually after riding a few miles/kilometers, if you bench test the pulse generators, keep the Ohm meter connected while you warm the generators with a good hairdryer, if the generator is shot it will drop to a zero reading.
If the reading doesn’t change when warm then the problem is somewhere else.

It was hot, after about an hour of riding. If they only fail when hot, shouldn’t they work now that the bike is cold if that is the problem?

Yes, the problem plagued my VF, it run for a few miles then died out as if out of fuel, it would restart when stone cold, I changed the igniter units believing them to be the problem, but the problem still persisted, usually after about about 30 minutes of riding, I followed the check through the system from the Clymer manual.
On another note, I recently changed the igniters with identical units because of a water problem, the VF is now much livelier in overall performance than previous, I don’t know why, but I intend looking into it more at a later date.

But the only difference Philjo is that mine don’t start or run on all four cylinders at all - hot or cold. I’d like to replace the whole ignition system with something with a bit more kick - any suggestions?