87 Heritage, where is my voes?
 

I was rebuilding my carb this weekend and noticed the vacuum hose from the intake was attached to nothing. Finally figured out that it should go to the voe switch. Looked in the factory service manual and it gave me nice schematics but no pics or location for the switch. I plugged the vacuum port but want to reconnect the (or a new) voes. Anyone know where this switch might be on the 87 FLSTC?

Some aftermarket ignitions dont use it so that may be why it is gone. Should be near the top motormount if I am correct..at least it was on mine.

That's where it is on mine too.

+1 on the top motor mount location, it can be hard to see with the tank on. If you aren't using it, you should cap off the vac line on the carb

On my 1991 FLSTC it was on the top motor mount and disconnected due to aftermarket ignition.

I had to change mine a couple of years ago, as the diaphragm had rotted, causing a vacuum leak and erratic running.

Getting it out of there was a horrible job. You could see it, but couldn't get any tools in there to pry off the stupid clip ring that holds it on the bracket. I ended up pulling both tanks and removing the upper motor mount, so I could remove the bracket holding the VOES. Maybe not a "horrible" job, but a lot more involved than it should have been.

By the way, how do these aftermarket ignitions get away without a vacuum advance?

By having programmable advance curves.

So how do they vary the timing for speed/engine load? I've always understood vacuum advance/retard to be a good thing. Just about every engine has used it since they took the manual spark advance lever off the Model T steering wheel.

The way my brother said it once is that vacuum advance was for mileage and mechanical advance was for power.


I know that probably isn't what you want to know but that is how he explained it to me.


He was a much better mechanic than I will ever be.

On my 87 Heritage , if you remove the air cleaner assembly you should see it sitting there. It is over by the upper mount. With the A/C out of the way, you can get at it to put the hose on. I replaced the hose on mine not long ago. If you don't see it with the A/C removed, then someone else has already removed it for you.

Thanks everyone, I found it with your advice, top motor mount as described. Plugged it in and the bike runs like crap, had to unplug it just to get it home. I guess I need to figure out what ignition system is on it to find out if it is mistimed or if the ignition system doesn't need the vacuum advance. I originally assumed it had the stock ignition but the points cover has 6 or 8 screws in it, definitely not riveted so I have to wonder. Do these ignitions that do away with the switch typically do nothing with the wiring?

Start by checking what's inside the nosecone. Some aftermarket ignitions are completely contained in there in place of the stock pickup. It will say what make and model it is and a quick Google should net you a manual. If it's just the stock pickup, look behind side covers and under the seat for an ignition box.

If that hose The end that goes to the voes) is open it may be causing a vacuum leak. Try putting a screw in it or something to close it off and see if the bike runs better.

I definitely will. Before I found the switch I pulled the hose off and put a vacuum cap on the port on the intake, but when I found the switch and put the hose on, it was gone. I guess it backfired and blew it off, so the screw in the hose makes sense.

The manual says the module is under the oil tank I believe, so it will definitely be easier to pull the cone. I'll try and sneak that in tomorrow and see what's in there, thanks.

I was surprised to find a stock 32400-80 pickup under the cover. Guessing I should start figuring out the issue with the voes. Going to try plugging the line first and adjusting the idle mixture. If I can get it running ok like that I'll try plugging the voes back in and go from there.

Follow the wires from the pickup to the ignition module and verify it's stock as well. If so, you'll need the VOES for sure. If it's aftermarket, check the manufacturer's literature.

From what I hear, sometimes a bike runs ok with stock setup and disconnected VOES...sometimes not. But if you have stock ignition you really should use it.