My Vf1000 frustrations

The lifespan would depend on many factors. Just like any other electronic device, temperature, humidity, shock/vibe, etc all play a role. It's difficult to say how long one should last. They have been known to fail from time to time, so I would say it's a possibility for any motorcycle of this age.

Many of the components inside the spark boxes are simple leaded devices such as capacitors, resistors, and a some transistors. Unfortunately those aren't usually what causes a failure. My experiences are that it's the chip that fails, and those are special parts. Even if you could buy one you would still need to know how to program it, which I'm not sure could be extracted from the chip. At minimum you would need help from someone at ND (Nippon Denso) which I don't see happening.

 

Geez,,,this is starting to sound a bit like my Atari Heavy Sixer,,,though I did find someone to rebuild it,,,so maybe there is hope.

 

As Jamie say's further down this thread, the units are man made so the old saying still applies (if it's man made it can stuff up) as for repair or remapping I honestly don't know, I presume there would be some guru out there who could but it would be better to find an alternative unit with programmable parameters, I know these are out there. I have been riding and racing V fours since 87 and have never had a failure of a CDI, unlike the digital ignition unit in my CBR sidecar which failed twice, usually at a critical moment (in a good finishing position)

 

I used a 1984 VF1000F wiring harness WITH the 1985 VF1000R ignition unit (black box) and it works fine.
You do have to re configure the wires. But all the right wires are there. Just condenses from one box from two boxes.

BTW way I have a complete extra set of Hitachi brand 1984 boxes that match if a member need them, or I would trade for a Black box from the 1985-86 for them.

I also have another black box for the 1984 VF1000F ( the one with the red plug.
It is a Nippon Denso brand.

When I first got my VF engine I was told it was a VF1000F and then later on found out it was a VF1000R late 1985. I was happy about that but then I had extra parts I could not use.

The black boxes will NOT interchange from the 1985 VF1000F to the VF1000R.
The timing is slightly different.

 

So whatI would like to know is.... Is the tachometer on the VF1000F and VF1000R only for displaying RPM?
Or asked another way...What does the tachometer do???

 

The tacho is there purely to dispaly the RPM to what is usually the most inefficient part of the bike- namely the rider in my case, although at times in the heat of competition it does get ignored. It is basically to display RPM so the operator can maintane the most efficient operating range of any given motor, not just the good old V Fours. I must admit when I began riding my CBR outfit I had to rely on the tacho much more until I got used to the sound, the old VF sounded like it was doing 5000 rpm at 10000 whereas the CBR sounded like it was doing 10000 at 5000, that is it sounded like it was screaming it's head off.

 

Thanks for that information.
And I agree that once you get used to the sound of the
bike you know when you are pushing it too far.


So I guess I have learned that the tach does
not tell the ignition system to do anything. It just displays the rpm.

 

All of this discussion brings up a question.
Will the VF1000R black box interchange with a VF1100?

Otherwise, could VF1100 Sabre black boxes be used on VF1000R's?

 

To the best of my knowledge the tach only displays the engine speed (rpm) to the rider. I am not aware that it performs any other functions.

 

I think the biggest difference would be the same as comparing to an F - the advance curve is likely not the same. Nor is the rev limit (I'm pretty sure). The differences are small enough that you could interchange without damage to the engine. All you you would risk is a loss of power.

 

I wrote a Email to Mick Smith and asked him directly for the answer to some of these questions to see what he would say.

Waiting for a reply.

 

Having just rebuilt My Vf1000FE I had problems my self(trained Motorcycle Mechanic With city and guilds from when I was Younger,
I had the same problem runs for a minute or so then starts missing a bit ,will not rev properly, I methodicly went through everything and came to the conclusion the fuel pump was sticking. So I sourced a replacement from a member of VF1000.com and it fixed the problem .The reason I thought it was running out of fuel was that I put the fuel filter so I could see it working which produced a bubble and I could feel it pulsing with my hand on the pump.I tested the pump and it stopped when the carbs were full but it did not restart when the pressure was lower in the fuel line.which is how these work
I think thats your problem
To test the pump connect it to a 12v battery,when its running put your finger over the inlet and feel it pumping air,next put your finger on the outlet and it should stop but as you take your finger off it should resume pumping,you might have rust inside the pump

Hope that fixes it
Long live the VF1000F

 

Here is the problem.

When you changed engines did you notice that the CDI boxes are different?

No you did not.
The 1984 had two CDI boxes.
The 1985 had only ONE CDI box.
The Gear driven cam engine has different valve timing than the chain driven cam engine. They will NOT interchange.

Th good thing is that the earlier F harness can be adapted for the later model single CDI box.

I did it- I know.

 

I got rid of the fuel pump.
Engine runs perfect.

 

V4 ignition module project

I'm now testing ignition modules for the V30 and V45 now with plans to reverse engineer all of the Nippon Denso modules for the early Honda V4's.

Looking for V65 modules and coils that can be used for a few days of bench testing and then returned.

Wondering out loud why others have not been successful with doing this before?

 

I can answer all of your questions and get your bike to run right.

I need to answer each question one at a time. So be patient.

The first thing that needs to be corrected is the CDI boxes.
The 1984 and 1985-86 have different CDI boxes and are NOT interchangeable.
It may run but it will not run correctly. The valve timing is different.

The 1984 model has 2 black boxes.
The 1985-86 has ONE box.

The good news is that the wiring harnesses can be adapted to BOTH boxes.

So that is the first problem that must be fixed. Get the 1985-86 black box and wire it in. The wires are color coded and if you have the shop manual with wiring diagram it is quite clear what needs to be done.

Now I will answer your questions about the carbs. Just a sec...
All of these things that you did were ok .
Fuel issues
Emptied tank and used fresh fuel.
Cleaned fuel tap.
Carbs removed and cleaned.
Carb vacuum rubbers checked. One replaced due to split.
Carb boots checked for cracks. Best ones refitted.
Replaced all fuel lines and new filter.
Carbs balanced (as best as possible – not easy on a v four).
Run with fuel cap off to exclude blocked breather.
Run with airbox removed to exclude obstruction.
Run without exhaust cans to exclude obstruction.
Checked for rag in exhaust collector box.


The one about the rag in the collector box was very funny(sorry) but that would be impossible if you saw the inside of a collector box. If that happened it would not run.
I have no idea how you would get it apart without destroying it.
You did not say how you balanced the carbs. That is another discussion. We will skip that for now.

You did not say if the carbs were from a 49 state bike or a california bike.
The difference is the venting of the carb float bowls.

But basically find the vent hose and make sure it goes overboard to atmosphere BUT does not stick out in the air stream. You cannot connect it to the charcoal filter because then it will flood and have other issues.
So #2 get that straightened out.
And by the way The "pan that the carbs are attached to can have the carb vent hose returning to it . That is the 49 state model.
Just make sure that on the inside of the pan where the vent hose goes that the little metal cover is over the end of the hose area so fuel will not be sucked out of the float bowls.

THE REAR CYLINDERS COLD ON START UP.
Two of your carbs are down draft and two are side draft.
If you do not believe me read the shop manual.
When you start it and you give it full choke it will start and it has to warm up before the back two cylinders start to sound like they are "firing".

What is going on is that the back two cylinders chokes (enrichment valves) may not be working. I have experienced that same problem. It is ok after a few minutes of warm up. You need to check the plungers on those two back carbs.

IT is hard to address the aspects of the running unless you tell me if you have a stock air box and stock exhausts. Is it all stock?


ELECTRICAL ISSUES:

"New spark plugs correctly gapped. (Tried both resistor and non resistor types)
New plug leads.
Coils swapped over with old ones.
Pickups on crank changed.
Wiring connections checked for obvious breaks.
New Battery
Run with fuse for instruments removed to exclude faulty rev limiter (apparently its in the tacho)."

IT would not matter if you used a resister or not. The resisters are to eliminate radio interference.
If you have no tachometer the engine will still work perfectly. Makes no difference.

 

tinkerinWstuff ,

I do not appreciate you peanut gallery. Bully.

 

Interesting project! Please keep us posted.

(per post 98 above: http://users.rcn.com/kochc/moto/spark/ig_repair.html)