i have a 1990 softail. problem is my motor was pinging like crazy. i retarded the timing until it stopped. now i found out my voes switch wasnt working, wouldnt hold a vacumn. ok i put another voes switch and idle went up, timing advanced, but after about a minute and a half it idled down to almost nothing. local harley mech. told me to just bypass the voes switch amd ground the wire that goes to it, did that and same thing, idle increased then fell off to almost nill. like the timing advanced then retarded to almost nothing. thing is, withpout the voes hooked up and the voes wire left disconnected, it idles great, runs good and no pinging. any thoughts on this. thanks

 

Possibly a bad Voes switch that you got? Sounds like something is causing the Voes switch to go bad, maybe the leads are shorted, and you are losing the switch as a result. When you remove the switch, your idle is good, right? I don't remember everything about the Voes switch from my Physics class, but if memory serves, as the vacuum pressure goes up, timing and spark is advanced...right?

So when you ground the switch, no good, after time...sounds like you're killing the switch. If you disconnect the switch, run it (you said it works well), then reconnect the switch, does it work for another minute before idling down to nothing? Perhaps something is saturating the swithch, again leading me to the wires. Did you test them? Are they gounded? Did you test them with the bike running?

Hope this helps, more of a brain storming session than a concrete answer. Tell me if I'm completely out to lunch and I'll stick to polishing chrome!

Mac

 

the switch hasnt worked since i got the bike, about a year and 1200 miles now. i checked the wire and it isnt grounded or shorted out anywhere. and, like i said, the bike idles great without it. its just when i hook it up that i have thr problem. first the idle increases, which is the timing advancing, then, after a minute, it seems like the timing retards alot, to the point that it hardly idles at all. grounding the wire does the same thing, so its not the switch. it just doesnt sound right, the idle that is. with the thing disconnected it sounds great, nice consistant lopey idle. im almost ready to buy a complete after market ignition system, that doesnt use a voes, to get rid of this problem. then again maybe im worring about something that i dont need to worry about.

 

Why not leave it disconnected and enjoy it? Maybe previous owner did something to it? You say it's working...I'd ride it.

Mac

 

Maybe this will help you out some

All Harley Davidson motorcycle carbureted models since the 1984 model year have used the VOES to improve throttle response, increase MPG, and meet EPA requirements for emissions.

The VOES is a motorcycle part described as a vacuum ignition retard device. That is, under low vacuum conditions the switch is open and has no effect on ignition timing. Under high vacuum, the switch closes and advances ignition timing. Essentially, the VOES is like the vacuum advance in older type automotive distributors.

The VOES is a normally open vacuum operated switch that closes under 3-5" of vacuum. The switch is connected to a lead from the ignition module. Under high vacuum, 3-5 inches or higher, the switch closes. A lead from the switch to ground closes a circuit in the ignition module. This circuit advances the timing of the spark. The advance increases throttle response and decrease fuel consumption and emissions.

The vacuum hose is usually connected to a port on the carburetor or intake manifold depending on motorcycle year and carburetor. There are several different VOES switches used the mounting bracket style and operating vacuum being the main differences. The FLHT models have a different vacuum range than the other models. However, just about any VOES can be adapted for use by adjusting the point at which the switch closes.

The point at which the switch closes.

The switches can be adjusted by removing the potted plug and adjusting the setscrew. You will need an accurate vacuum gauge and vacuum hand pump. We have been able to set the operating point as low as 2 inches and as high as 7 inches.

Why would you want a VOES?

We have experimented with converting 1972 and later ignitions from points to electronic ignition. We have used Dyna 'S' conversions for H-D's. We have used Crane, Compufire, Spyke and other Harley Davidson conversion kits. With some of these such as the Dyna 'S', you still have to use the mechanical advance system. This requires service and routine maintenance.

Others work very well having digital advances and provisions for a VOES switch. We experimented with installing a VOES in a 1983 FX and found we have improved throttle response and better mileage. We also routinely install the VOES in custom built Harley Davidsons and even our own Kenny Boyce framed Harley FXR's use VOES with a Crane HI4 module. During Dyno runs, we found that part throttle roll on power was increased as was throttle response.

We believe that most street ridden Harley Davidson motorcycles will benefit from a VOES.

For racing applications or supercharged, turbo-charged or bikes using Nitrous Oxide, we do not recommend using a VOES. This is due to the possibility of a sudden timing change causing a backfire which can be a bad thing under these conditions!

What I would suggest is to time the engine properly with a light and re hook the switch and see what happens. The switch is adjustable for inches of vacuum and may be off in your application. Also check for intake leaks and the integrity of the vacuum line from the cartb to the VOES for cracks/holes.

 

well i hooked it back up and everything works great now. funny, i have to set the idle at a certain point, any lower and thats when it will drop to almost nothing in a minute or two. anyway it seemed to be working.

 

THe voes is adjustable I like to use the bagger setting and when adjusting it. You have to remove the sealant fron the end to make adjustment and make sure you put a dab of silacone back on it. Goood luck