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[fxr4mikey]

The VOES is the Vacuum Operated Electric Switch. It converts vacuum to an electric signal. The vacuum hose must be connected. You also have a Vacuum actuated petcock that only will remain open under vacuum. Again, the vacuum hose must be connected. A vacuum pump connected to this petcock will keep it open if no vacuum is present, as in a non-running motor, if ya wanna check that.

You don't HAVE to have a 'pump' .... you can just hook a hose to it and suck on it, then put your finger over the end of the hose ... once the valve opens and the fuel begins to flow, as long as you hold your finger/thumb over the end of the hose the valve will remain open.  I use this method to drain my tank before I remove it from the bike.  Just run a hose from the petcock to the gas can, put a hose over the vacuum on the petcock and a tiny suction will open the petcock..... but I'm sure you already knew all that   LOL


 I remove all that chit from my Evos!

Hoist!

Good Answer   

I've contemplated removing that, but have decided not to .... . the VOES works good in conjunction with the ignition advance

[Hoist!]

Good Answer   

I've contemplated removing that, but have decided not to .... . the VOES works good in conjunction with the ignition advance

Not with a Dyna S ignition it don't!

Hoist!

[fxr4mikey]

Not with a Dyna S ignition it don't!

Hoist!

Compu-Fire ............ just saying    LOL   

[Hoist!]

Compu-Fire ............ just saying    LOL   

HeHe!!! That's pretty funny Mike.

I was trying to say I usually pull the brain and the VOES out on my Evos. I use a Dyna S ignition, which is basically electronic points. It uses a mechanical advance unit, but no points to set. I left it in on Joy, because I'm using a Dyna 2000 single-fire programmable ign. on her. But Compufire away!!!

Hoist!

[fxr4mikey]

ya man ..... compu-fire on  LOL

You're funny man !!!!!  I can't WAIT to meet up with you !!!!!!!

Here, this should be useful to some, others won't care......

this was taken from the daytona-twintec site (linked below) and is an excerpt about single fire ignition systems




What is the VOES switch?

    The VOES switch senses manifold pressure. Most carbureted H-D® models manufactured from 1980-98 and some later Sportsters® (Mikey is putting this here .... FXR's in 1999 also have VOES on them - as did several 'other' bikes, not just Sportsters..... gezzzz)  use a VOES switch to increase ignition timing advance during idle and cruise conditions. When manifold pressure (MAP) drops, the normally open VOES switch closes and connects the ignition module's VOES input (violet/white wire) to ground. The green VOES LED will illuminate. The ignition module then uses the low MAP advance curve. If you look at the advance curves published in our instructions, you will see that the low MAP curves are somewhat more aggressive than the wide open throttle (WOT) curves. The additional advance stabilizes the idle and improves cruise fuel economy. The VOES switch has no effect on wide open throttle (WOT) operation.

    During normal operation, the green VOES LED should illuminate during idle. If you have installed a high performance camshaft or made other major modifications, manifold pressure may run higher at idle. In this case, the green VOES LED will not illuminate at idle. You should still see the green VOES LED momentarily illuminate if you rev the engine up to about 2,500 RPM and then close the throttle.

    We recommend that you leave the VOES switch connected. If you have a motorcycle where the VOES switch was removed, we recommend that you replace it. We offer P/N VOES-KIT-MC7. This is a complete kit with mounting bracket and has a vacuum switching level of 6-7 in-Hg that helps eliminate spark knock under light load or throttle roll-on. 


I lifted this from this site - they have some really good info there about ignition systems      ENJOY EVERYONE !!!!!!

http://www.daytona-twintec.com/tech_evo.html

[elvislee]

Ok guys, I'm fixing to get back on the bike here in a bit and after reading your info on VOES; it makes me wonder.

When I first pulled my fuel tank off as I mentioned in another thread, I found crap in the tank and pulled the petcock off to clean the fuel filter. I also disassembled the petcock to check for foreign matter inside. I'm fairley certain  maybe  that I assembled the petcock correctly before putting it back on the tank  Could this be a problem in line with your VOES input  Thanks guys 

[Hoist!]

Ok guys, I'm fixing to get back on the bike here in a bit and after reading your info on VOES; it makes me wonder.

When I first pulled my fuel tank off as I mentioned in another thread, I found crap in the tank and pulled the petcock off to clean the fuel filter. I also disassembled the petcock to check for foreign matter inside. I'm fairley certain  maybe  that I assembled the petcock correctly before putting it back on the tank  Could this be a problem in line with your VOES input  Thanks guys 

The commonality between the petcock and the VOES is that they both use a vacuum connection from the intake manifold. You can replace the petcock with a manual one and block off the vacuum connection with no impact. But you need to use a new ignition that can operate without a VOESto remove that. The stock or SE brain needs the VOES. Certain aftermarket ignitions don't. That's the only way to eliminate the VOES.

Hoist!

[elvislee]

The commonality between the petcock and the VOES is that they both use a vacuum connection from the intake manifold. You can replace the petcock with a manual one and block off the vacuum connection with no impact. But you need to use a new ignition that can operate without a VOES to remove that. The stock or SE brain needs the VOES. Certain aftermarket ignitions don't. That's the only way to eliminate the VOES.

Hoist!

Thanks Hoist...I don't really want to eliminate the VOES...What I am asking is:  Since I DID remove the petcock and I did disassemble the petcock; would my disassembling the petcock have a negative effect in loss of vacuum or affecting the vacuum to the point that the motor won't start now. Just trying to get some ideas...  

[Hoist!]

Thanks Hoist...I don't really want to eliminate the VOES...What I am asking is:  Since I DID remove the petcock and I did disassemble the petcock; would my disassembling the petcock have a negative effect in loss of vacuum or affecting the vacuum to the point that the motor won't start now. Just trying to get some ideas...  

No, one thing has nothing to do with the other, UNLESS you don't have the vacuum line on, or diaphragm installed right and are losing vacuum. But the VOES works toward the advance function of your ignition, so it shouldn't affect startup, where you'll typically be retarded, not advanced. You can check the function of your petcock with a hand vacuum pump or by sucking on it to get it to open. If the petcock's functioning properly, and you have no vacuum leaks, this is definitely not the problem. Sounds electrical though. Check all the connections to make sure you didn't knock a wire off somewhere like the coil, or maybe the VOES.

Hoist!

[fxr4mikey]

No, one thing has nothing to do with the other, UNLESS you don't have the vacuum line on, or diaphragm installed right and are losing vacuum. But the VOES works toward the advance function of your ignition, so it shouldn't affect startup, where you'll typically be retarded, not advanced. You can check the function of your petcock with a hand vacuum pump or by sucking on it to get it to open. If the petcock's functioning properly, and you have no vacuum leaks, this is definitely not the problem. Sounds electrical though. Check all the connections to make sure you didn't knock a wire off somewhere like the coil, or maybe the VOES.

Hoist!

don't you have to have the vacuum hose connected to the VOES in order to start the bike ?  The VOES sends a signal to the ignition module to tell it which curve to use (advanced or retarded).  How would it start without this, using STOCK ignition module, or SE module, which also uses VOES. ?

I like this place, I'm LEARNING 'suff' everyday   

[Hoist!]

don't you have to have the vacuum hose connected to the VOES in order to start the bike ?  The VOES sends a signal to the ignition module to tell it which curve to use (advanced or retarded).  How would it start without this, using STOCK ignition module, or SE module, which also uses VOES. ?

I like this place, I'm LEARNING 'suff' everyday   

That's what I said Mike, or implied anyway. As long as you have NO VACUUM LEAK. Block off the petcock vacuum line so it's only going to the VOES and you'll know if the petcock is causing it.

Hoist!

[fxr4mikey]

Elvis ....

here's an easy way to determine if your petcock is working properly

get two pieces of tubing  one for the fuel and one for the vacuum

the fuel line is 3/16" Inside Diameter (ID)
the vacuum line in 1/8" ID

1) turn the petcock ON, fuel WILL NOT FLOW WITHOUT A VACUUM on the stock petcock
2) disconnect the fuel line from the petcock
3) disconnect the vacuum tube from the petcock
4) connect up your tube to the fuel line on the petcock (the tube should be long enough to reach to the floor) put the other end into a gas can or collection item of your choice, it needs to hold GASOLINE
5) connect up your vacuum tube to the petcock vacuum
6) suck on the vacuum line - if your petcock if functioning correctly, this will OPEN the diaphragm and fuel will begin to flow thru the fuel tube to the gas can
  6a) fuel will continue to flow as long as there is a vacuum on the petcock, you can maintain that by placing your finger over the end of the vacuum tube once the fuel begins to flow. 
  6b) this is the method that I use to drain the tank when I'm going to remove it from the bike.
  6c) if you use this method, and are planning to DRAIN the tank
    6c1) make sure the petcock is set on RESERVE, otherwise that gas remains in the tank
    6c2) if you can, set the bike up straight, or on a jack, otherwise there will be fuel left in the tank because of the lean angle, the gas runs to the side, and not all is directly over the petcock
7) if you are getting fuel with this method, then there is nothing wrong with your petcock
if not, you need to find out what you did wrong with the re-assembly of the petcock


Good Luck !!

Let us know what you find !



Mikey

[elvislee]

Elvis ....

here's an easy way to determine if your petcock is working properly

get two pieces of tubing  one for the fuel and one for the vacuumthe fuel line is 3/16" Inside Diameter (ID)
the vacuum line in 1/8" ID

1) turn the petcock ON, fuel WILL NOT FLOW WITHOUT A VACUUM on the stock petcock
2) disconnect the fuel line from the petcock
3) disconnect the vacuum tube from the petcock
4) connect up your tube to the fuel line on the petcock (the tube should be long enough to reach to the floor) put the other end into a gas can or collection item of your choice, it needs to hold GASOLINE
5) connect up your vacuum tube to the petcock vacuum
6) suck on the vacuum line - if your petcock if functioning correctly, this will OPEN the diaphragm and fuel will begin to flow thru the fuel tube to the gas can
  6a) fuel will continue to flow as long as there is a vacuum on the petcock, you can maintain that by placing your finger over the end of the vacuum tube once the fuel begins to flow. 
  6b) this is the method that I use to drain the tank when I'm going to remove it from the bike.
  6c) if you use this method, and are planning to DRAIN the tank
    6c1) make sure the petcock is set on RESERVE, otherwise that gas remains in the tank
    6c2) if you can, set the bike up straight, or on a jack, otherwise there will be fuel left in the tank because of the lean angle, the gas runs to the side, and not all is directly over the petcock
7) if you are getting fuel with this method, then there is nothing wrong with your petcock
if not, you need to find out what you did wrong with the re-assembly of the petcock


Good Luck !!

Let us know what you find !

Mikey

Thanks Howie and Mikey...I'm gonna try this method to test the petcock. The more I think about it; I think this may be the problem...I should be able to do this today...I'll let ya know...Thanks again guys 

[Hoist!]

Thanks Howie and Mikey...I'm gonna try this method to test the petcock. The more I think about it; I think this may be the problem...I should be able to do this today...I'll let ya know...Thanks again guys 

Blaine, surely check the petcock to make sure it's functioning. The purpose of that vacuum operated petcock it to make sure the gas is off when the motor's shut down. Not a very important funtion IMO. Some might like this safety feature. But I could care less about that and always look to remove any unecessary vacuum connections from my bikes. Get yourself a manual petcock (really cheap for a regular one, more $ for a Pingel) and eliminate this issue from the picture. If yours is bad, you still won't be able to start the bike anyway. Putting on a manual one will elininate this from the picture and allow you to know you can proceed with the troubleshooting if she doesn't fire right up.

One other thing came to mind. Didn't you say you were cleaning the tank out while it was off? If so, you could have disturbed some debris that worked its way into the carbs circuits. Don't know if this was possible since I'm not sure exactly what you did and didn't do. But if ya did, look at that too.

Hoist!

[elvislee]

Blaine, surely check the petcock to make sure it's functioning. The purpose of that vacuum operated petcock it to make sure the gas is off when the motor's shut down. Not a very important funtion IMO. Some might like this safety feature. But I could care less about that and always look to remove any unecessary vacuum connections from my bikes. Get yourself a manual petcock (really cheap for a regular one, more $ for a Pingel) and eliminate this issue from the picture. If yours is bad, you still won't be able to start the bike anyway. Putting on a manual one will elininate this from the picture and allow you to know you can proceed with the troubleshooting if she doesn't fire right up.

One other thing came to mind. Didn't you say you were cleaning the tank out while it was off? If so, you could have disturbed some debris that worked its way into the carbs circuits. Don't know if this was possible since I'm not sure exactly what you did and didn't do. But if ya did, look at that too.

Hoist!

Well...Where do I start?

Went and bought some tubing like ya said Mikey and followed all steps...NO FUEL came out of the tube and I was a sucking big time..No smart a$$ remarks either 

Then pulled the petcock back off today. Disassembled it again and started looking at how I put it back together. After looking at it and thinking of the vacuum process and how it works that you and Mikey explained; I realized I may have assembled the spring in the petcock in the wrong place. If you tear the petcock down you remove the 4 screws on the vacuum nippile side of the petcock and the petcock divides into three separate pieces. The back side (with the vacuum nipple), the middle section that holds the rubber flange, and the front section between the flange and the lever which allows the fuel to flow out the nipple to the carb.

Now...when looking at it after I disassembled it the very first time; I had put the spring back in between the middle section which holds the rubber flange in place and the rear section that holds the vacuum nipple. As I looked at it I began to think if the power was turned on and the vacuum began to suck onto the flange that it couldn't because the spring wasn't allowing it to open up and drop fuel to the front to go to the fuel line and eventually to the carb.

I then reasoned if the spring was placed in the front section of the petcock, then when vacuum is applied; it would suck on the flange, drop the fuel into the front section and allow the fuel to the fuel line and into the carb. So, to help me with this theory I went to the service dept at the HD shop and showed them the petcock disassembled and asked them if my theory was correct. He told me it sounded right but could not confirm this theory  another tech overheard us and asked what king of bike I had and he said....Yep...You guessed...."They stopped making Fxr's in 1994". I just turned away and put my s^&t back in my bag and waled out....Oh...did get my SE Ignition Module while I was there.

Now I'm back home and I put the petcock back in and hook everything up. Double checked the carb seal to the rubber seal ring on the carb that connects to the manifold and the best I can tell all was sealed good. Double checked my wiring connections and all seems good. Put the gas tank back on with about a gallon of fresh 93 octane fuel and turn it over, and over, and over, and over....No start...same as before...Turns over great but no spitting, coughing, choking, sounding like it wants to kick in or anything.

So, now I'm gonna go back out when I get my bearings and quit cussing and do the Mikey vacuum test again because I didn't do it when I changed the spring around in the petcock and see if I can suck some more and get fuel to come out...If no fuel comes out then I'd say based on what I've been told that the petcock is not working properly and I will probably go buy another one or a rebuild kit; then go from there...GEEEEEZZZZ....Wish me luck guys