VOES Dissection

[biknut]

This is the inside of a VOES. Some of you may remember what a VOES is. Basicly a devise designed by cavemen ignition designers back in the last century to help our bikes run better, and get better gas mileage. VOES stands for, Vacuum Operated Electric Switch. It's job is to switch the ignition between two different ignition curves. One for power, one for gas mileage. It's operated by manifold vacuum.

This is our sacrificial specimen






Here's a look at the adjustment screw.






This is fun









Now we're going in




Finally we get a look at the diaphragm




The orange button in the center operates the switch.




Looks like there's a micro switch in there


in order to remove the micro switch we need to dig this crap out of the other side.


Here it comes


Kind of like pulling a tooth



On the side it has a part number, 1647RJ also S S-5-2 T

Switch rating is 5A@125V or 3A@250V AC

[groovemeisterus]

Biknut,

Very Nice and detailed! Kudos!

I'll try and do the same with my old stock 883 ignition to see what
component the VOES wire actually connects to, find the specs, and post my findings.

and Biknut rocks!

[Mattbastard]

While it does switch between two ignition maps, in reality the cause is to retard timing during very heavy throttle (indicated by a shallow vacuum) to reduce pinging. The mileage map is what your bike is in most of the time.

How you gonna put that back together?

[Jason's Sporty]

I wonder what would happen if a toggle switch was used instead of the voes?

[BWP 5p]

Originally Posted by Mattbastard

How you gonna put that back together?

Yeh........and I want to see the inside of the micro switch!

Maybe a guy can change the spring rate in there to change the timing of when it changes!

[wilbur]

Originally Posted by BWP 5p

Maybe a guy can change the spring rate in there to change the timing of when it changes!

[biknut]

Originally Posted by Mattbastard

While it does switch between two ignition maps, in reality the cause is to retard timing during very heavy throttle (indicated by a shallow vacuum) to reduce pinging. The mileage map is what your bike is in most of the time.

How you gonna put that back together?

Right, but I would put it a different way. Under heavy throttle, the VOES switches the ignition curve to one that is very similar to a mechanical advance.

Under light throttle it switches to a curve that is a lot more advanced at lower speeds for better gas mileage.

Maybe someone can remember the years Sportsters had a VOES. I know the late Iron Heads had them, but I don't remember what year was first. I think 03 was the last model year they were used. There's one on my 01 model.

[groovemeisterus]

Biknut,

Per our discussion in the VOES sticky I made some measurements
on my ride.

You are right. 5 Volts or so with nothing else connected indicator wise.
With my setup with a 12V getting turned on to light up my Oil light,
I measured 12V.

I disconnected my indicator light and had a ride today and WHOA,
what a difference it made. WAY more responsive. I did also use
my vacuum meter to get VOES back to stock 5 in/mercury vacuum.

But WHAT a difference it made. WAY more responsive.

Might be a good idea to update the VOES sticky for others to NOT
have a similar indicator setup like I did using the VOES switch to
light up the indicator light to show when the VOES kicks in and out
using the BATT voltage of 12V, since there is already 5V stock.

I will rip apart my old stock 883 ignition tommorrow and find where the
VOES connects to what component, and figure out how and why different
loads/voltages effect the IGN curve.

I noticed a BIG difference by just disconnecting my indicator and
had a GREAT ride today.

There is something on the VOES line that really DOES effect the IGN
curve if the indicator is not connected properly!

I was going stop light to stop light, and passing cars like never before...
and it all boiled down to an in different VOES indicator setup!

I will redesign my indicator setup circuit, tear down my old 883 IGN module
like you did your old VOES,
and try and find out how or why different loads effect the IGN performance
per the components used from an HD IGN module.

WOW! BIG difference if not done right!

Thanks for the great discussions! I would prob never thought twice
until we discussed this issue!

[Pash]

Great post - very informative.

Switch part number SS-5-2T means:

5A / Normally Closed / Spade terminals

http://www.farnell.com/datasheets/1509316.pdf