VF 500 tooth pattern on the crank sensor trigger wheel

I am on the way to install an EFI on my VF500, and among other things I need to know:

1. What is the tooth pattern on the crank sensor trigger wheel (and cam
sensor trigger wheel, if there is any?)
2. How many degrees separate each of the ignition firings?

Can anyone give me a helping hand

 

I know all about the VFR 750 ignition systems, but not the VF500. Do you have any pictures of the sensors and sensor wheel? Does it have 1 or 2 ignition boxes? 360° crank?

 

Okay, I did a bit of looking around and it seems the VF500 has the same basic setup as the bigger VF750 which is a 360° crank, 2 dual output coils, 2 ignition boxes, 2 crank triggers and a single raised tooth to signal the crank triggers.

Basically your efi system will need to use the factory two crank sensors. In stock form one sensor fires the front coil and one fires the rear coil. When one of the front cylinders is at top dead center and the coil fires, the cylinder next to it is on the exhaust stroke and fires as well (which doesn't hurt anything).

The one problem I see with getting the EFI to fire correctly on your bike is that there is no cam sensor, so the EFI won't know which of the 2 cylinders needs fuel. You might need to add one, but that is easier said than done. If your fuel injection system fires in batches, 2 injectors at a time, then you may be good, but it's not very fuel efficient.

Here is a pic of a VF500 Magna starter clutch. It's basically the same design on your bike. See the one long pulse trigger?





Here is a pic of the 86 VFR750 Starter clutch. It has 2 triggers, but you can only see one in this pic. This is very close to what your bike will look like. The key here is the 2 pulsers or crank sensors. See how they line up with the cylinder bank that they fire? They are 90* apart, just like the cylinders. The front edge of the trigger is at about 50* BTDC and the end is about 15* BTDC.





Your bikes firing order is the one on the left in this pic:




Cylinder 1 fires, then 90* later, cylinder 4 fires. Then 270* later, cylinder 3 fires. Then 90* later, cylinder 2 fires. Then it's another 270* before cylinder 1 fires again.

So it's 2 cylinders firing close together, then a long gap, then 2 more firing close together, then a long gap again.

If you want more details on the ignition system contact Ray San at ray_san@internode.on.net. He builds ignition boxes for the 1st gen Honda V4 bikes.

 

Thanks a lot, the reply was really helpful!

 

Do you know someone who installed EFI on VF750, or on a VFR, I would appreciate to know about their experience.

 

I've never seen or heard of it done before. I don't know where you would find a set of throttle bodies that would mount above the intakes at the correct angle and spacing.

Personally I would assume the costs involved would easily exceed the value of the bike. I assume your bike either has sentimental value or else you have a lot of money and just want a challenge.

Why were you wanting to convert it to Fuel Injection?
What was your plan, a stock fuel injection system converted to your bike or an aftermarket system?

 

Once again, thanks for the help and useful advice. Actually the bike has sentimental value for me, and I like a chalenge. However I don't have a lot of money, but I will try to finish the project with resources that I have.

I was planing to make a custom made mount (using the mount of a VFR800 as inspiration and a scale up template) on which I will probably attach throttle bodies from a CBR600.

For the ECU, I received offers from some manufacturers but they were really expensive. However with Microsquirt I could probably get everything done within 1000 bucks, providing that my throttle bodies and mount function properly.

From the start had this idea of using a VFR800 ECU, but I didn't know if it is possible. Is there a chance to do that if I install a cam sensor, or there have to be other modifications. If I manage to make it function with the VFR800 ECU, this would cut my expenses drasticly, and make me a happy man.

I live in Montenegro (Europe, former Yugoslavia), and the labor costs here are not so high as in the US, or western Europe, so I hope to get everything done DIY and with help from friends and mechanics, and other professionals.

 

The reality is that this conversion may not be cheap. I know those bikes can run really well with the stock carbs, so I don't see much improvement going to FI, but I'll help anyway as it is an interesting project.

The big problem I see with putting together 4 throttle bodies is the linkage. It has to be accurate, precise and reliable. If one TB gets a tiny bit out of sync it can make the bike run poorly. You may consider getting a vfr800 throttle body assembly and mocking it up to see how well it fits over your 500 engine. If the outlets and inlets line up closely you may be able to make up the difference with some custom metal tubes that are offset slightly and maybe neck down in size. From that point you'd just need to swap in some smaller injectors and you'd be set.

The ignition system will be a problem. The best solution I can see would be hammer down the big trigger on the starter clutch so it's round. Then have a custom metal ring laser cut and welded onto the starter clutch that will match what is on the vfr800.

The 1st Gen Honda v4's and 86 model vfr all used a hybrid analog electronic ignition system. The 87 vfr and up went digital. They use an 11 tooth pick up wheel with the 12th tooth missing to create a reference point.



You would still need to add a cam sensor, though. Factory cam sensor pics are hard to find. Bolting a small sensor under one of the valve covers shouldn't be too difficult, but attaching a trigger to a cam is gonna be tricky as they spin to 6,000 rpm or so and get really hot.

Keep in mind the 87 and up vfr bikes use a 180* crank, while your bike uses a 360* crank. It just means you'll need to not hook up 2 of the 4 vfr ignition coils. You'll just run the stock 2 dual output coils and only use 2 of the coil outputs from the ecm. No big deal there.

 

As for fuel, I doubt you'd be able to fit a pump into the tank. You could build a small auxiliary tank under the seat just big enough to fit a pump into and gravity feed fuel from the main tank into it. Maybe run a tiny lithium battery mounted elsewhere and put the extra tank were the stock battery would fit?

The extra tank would keep the pump in fuel to keep it cool and quiet, plus it would be easy to plumb in a return line.

 

Assuming you got a cam sensor installed, throttle body assembly installed and crank trigger installed, I think your still gonna need to have the vfr800 ecm custom programmed to remove the emissions stuff and maybe a little tuning work done.

Adding the 2 oxygen sensors the vfr800 has shouldn't be too hard to install. Just weld in bugs and install.

The air box under the tank will probably need to be custom built or at least the stock vfr800 one modified to fit under the VF500 gas tank.

I don't think any of the other sensors should be a problem.

 

I just looked up a picture of the vfr800 throttle body and man is it different looking. It doesn't seem to be angled at a V shape, plus it looks really wide. The 2003 and up throttle bodies look like they can be narrowed with a little cutting and welding then some angled adaptor tubes made to mate them to the VF500 engine.

This would definetly be a big project.

Heres a thought, maybe the stock carbs can be converted to act as throttle bodies. You just need to weld in some injector bungs, block off all the other tubes and mount a TPS onto it.

 

About the cam trigger, I am aware that this is probably the biggest issue in this conversion and I hope to find the right person to help me with that. Do you have any idea or know someone who has done this sort of modification?
The idea for the carburetors is something that I thought about as well, and I think that it could function well.
For the fuel pump, I'll can go with your suggestion or simply replace the tank with one with a fitted fuel pump.

 

Here is a discussion about a similar issue:
http://www.3geez.com/forum/restorat...-distributor-less-crank-fired-ignition-3.html
Do you think that I can apply a similar solution?

 

Hi, this is Luis. I just found the thread.. I'm trying to build a project just like this one, adding efi to my vf 500. I have allready purchased a microsquirt and got Yamaha R6 throttle bodys. I don't know yet if i'll make it fit in there... I'm try to make it run in a vfr 750 engine first (i just got the engine, no bike!) i was wondering if i could replace the trigger wheel from the vfr with 12+1 tooth for the original 1 tooth trigger wheel. Do you know if it will fit?

 

If you're interested in seeing an example of the process of putting together a Microsquirt-controlled fuel injection conversion you can look at my Suzuki GSF400 build thread over on Bandit Alley: http://forums.banditalley.net/index.php?topic=13747.0

Everything I've done to this Bandit 400 is applicable to your VFR500, with just a few little tweaks to work around the V-4 engine configuration.

 

Long live carburetors !! I'm betting that none of your home-built EFIs will ever work as well as the original carbs. :eek-new: Just consider that the Honda FACTORY cannot get low-speed fueling smoothed out on the 800 bikes, thus requiring a pOWER cOMMANDER. So w@#HAT CHAnce does a home tinkerer have to get everything dialed-in correcly throughout the rev range??

Anyone who isn't competent to clean and rebuild carbs to good working order probably won't be capable of a proper EFI installation either as it's far more complicated. :frown-new:

 

I disagree. On a positive note, I'm glad to see people that like the older Honda bikes so much they keep them on the road and try to improve them as opposed to just going out and buying a newer bike. I think it says something good about Honda design.

 

Hi Luis, unfortunately I don't know will this trigger wheel fit because for now I've stopped my efi project because of the modifications on the engine, and in my town there was no mechanic that would guarantee me that the replacement of the trigger wheel would go without problems.
However this is an interesting project and the efi would be a really good improvement for this bike. So I think you are doing really well for trying to make the efi work first on the 750 engine. Later, If you make a precise fitment of the 750 trigger wheel on the 500 engine there is no reason for the vf500 engine not to run, and therefore you can install the efi, since you've reassured yourself that it can work on the 750 engine.