Who understands the PAIR system to know I can clamp it off, leaving it in place?

John OoSTerhuis said:

JTBC - apply vacuum with your mouth and quickly pinch off that end of the hose. Then watch he gage for bleed off/leak. It should hold the vacuum for quite a while.

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My heavens, what a day chasing leaks. There's more than one reason air will escape. In my case, having gone from losing an inHg every 3 to 4 seconds, to holding vacuum steady. Whether it was methodically changing out vac hoses that might have had a hole in it to changing out "T" connectors that just might not have been large enough for the vac hose to make a good seal. Looking forward to the test ride tomorrow. The vac gauge was very important in knowing the integrity of the system since I was having problems. 2nd to having a gauge is having something else that produces suction other than me.
As I'm set up now, cylinder #2, #3 and #4 are connected with "T" connectors before the one way valve (properly oriented) to a "T" connector that joins the servo and vac container. I'm ready.

Edit: Forgot to mention #3 likely isn't needed for the servo to function properly, I just left it connected. The timing of #3 vac coming available is because my petcock started leaking, so I took it out, connected the fuel filter direct to the carbs and made a hole in the fuel cap. I found a rebuild kit for the petcock for 26.00 at partsandmore. Until I found that one, they've been at least 54.00.

DAS said:

Maybe my only issue is weak vacuum so I should put a vac. gauge on it to monitor the vacuum at the control unit when riding.

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This is a good idea. A few posts back, Mark mentioned lower than 6 inHg the system will kick off due to low vacuum. Another "T" fitting with a cap for the extra port, when not in use, will allow a quick connect for diagnostic at idle or a test ride.
I found with about 2000 to 2500 rpm in neutral, the servo will engage temporarily, enough to see how much it will dip. Do you have a vac container? I do, and can tell you if the next test ride fails, I'm building a larger one. My prediction, with such a profound vacuum leak, likely due to "T" connectors that weren't large enough in diameter, I shouldn't have the problems I was having. That and having improperly installed the rubber diaphragm the last time I had the servo apart.

Despite everything I've been through, and completely not qualified to begin opening this thing, putting it back together, opening it again, then putting it back together more right than the time before, it kicks off at the slightest hill. This is with it holding a vacuum yesterday, with all the testing. On top of all of the defeats, I can still try to disconnect cyl #3, or use #3 and bypass #2 and #4, but the memory remains from it disconnecting while on flat ground and no vacuum leak, that the issue is probably not vacuum related. It has to be a problem with the unit itself and it's more frustrating I may never know why, than not being able to use cruise. I need to put the tupperware back on for the day, but totally appreciate you guys hanging in there with me through the deduction process. Thoughts.

While reading more forum information on the subject of cruise I found that Murph's kits offers the servo only for 100.00. Makes it hard not to do that since my mom sent me an early birthday present, more than enough to pay 100.00 for a different servo. I really have to search deep for whether I pursue making this work, I've ridden close to 50k miles on this bike without it and consider myself a practical person. Sure, cruise is awesome, I've used it in a car for 10's of thousands of miles, I'm just defining need here.

One last thought before a new servo - leaky one-way check valve. Do the static vacuum leak down test with the valve installed.

Sorry this has been such an ordeal. In the immortal words of the sage, Red Green: "Remember, I'm pulling for ya. We're all in this together!"

John

moddy said:

The vac hoses under the carbs? If I have to pull the carbs, to repair the lines, it isn't that bad.

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No, you shouldn't have to remove carbs at all...


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John OoSTerhuis said:

One last thought before a new servo - leaky one-way check valve. Do the static vacuum leak down test with the valve installed.

Sorry this has been such an ordeal. In the immortal words of the sage, Red Green: "Remember, I'm pulling for ya. We're all in this together!"

John

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I had the vac gauge installed on the side of the servo and vac canister. It held 12 inHg on the gauge for as long as I wanted to wait. It doesn't mean, that it would hold it consistently. I didn't let the vac escape then introduce vacuum again for the same test. I had to apply vacuum so many times because I needed to change the system enough for it to hold vacuum, the final time I introduced vacuum and the one way valve held the vacuum, I took it as I was done.

I've seen every episode of Red Green, thanks for the reference. I'll wait to order the servo. I'll let some dust settle, taking a rest. There are still some things I haven't done, like ride a long with an active vac gauge. It would prove an inconsistent vacuum integrity.

I can't give up yet. I never ran the bike to see what remained in the system on the other side of the one way valve. Maybe there is a better one way valve to use, even though it was a fiver at the parts store. I can still make a larger vac container as well, need to check the one way valve first.

Another possibility since we're trying everything under the sun is a one-way valve at each vacuum port instead of leaving it to 2 vacuum connections before the only one-way valve.

Yesterday I found a problem with my cruise control as well... hopefully a simple fix.... when I hit the front brake, the cc doesn't cut out like it should... if I hit the rear brake it does... I checked when I hit the front brake, the rear light does not light up, so either the switch which I will check first, or to to with the wiring to the switch... I'll check it out this morning to see what I find....


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the front brake lever/perch the switch is in the mount, but the wiring is crimp on style connections. they are easy to work loose, unnoticed.

So, I'm headed to Louisiana. Long story short, I was requested to be there 3 weeks ago, while I was working on the cruise, then no funds were available for it. Funds were recently approved so I'm riding to Louisiana without having finished the cruise control saga. When I return. I will be exploring the one way valve, I don't think it's consistent, if it is, I don't think I'm consistently holding a vacuum, or the volume isn't large enough. Either way, it will be approximately a month before I return to this thread for more cruise control mayhem.

Late to the party, but here is my setup. I have one way valves off of 2 of the carb vacuums and one from the pair hose, they are "T" to the vacuum canister that I bought off Murph's kits. The throttle cable is in line with the throttle cables and I have a few beads of slack. This is working well for me. Though I did have a defective one way valve that I had to replace. Hopefully you will get your issues resolved
chee
rs

kiltman said:

I did have a defective one way valve that I had to replace.

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I've had scads of time to think about this over the last three to four weeks of different symptoms and different inconsistencies. I don't have more than one one-way valve. The third cylinder and the vacuum from the PAIR go to the one-way valve before it goes to the VAC system. I think my one-way valve is inconsistent therefore losing vacuum. When I get home I'm going to mount a vacuum gauge to the system to help see what's going on.

At long last I have the Tupperware off again and am using my mityvac to create a vacuum testing the reservoir, one-way valve and the servo. Not being able to find any test parameters for the PAIR, is it supposed to be able to hold a vacuum when you separate the second and fourth cylinder from it?

moddy said:

At long last I have the Tupperware off again and am using my mityvac to create a vacuum testing the reservoir, one-way valve and the servo. Not being able to find any test parameters for the PAIR, is it supposed to be able to hold a vacuum when you separate the second and fourth cylinder from it?

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See my post (#8) for test procedure and specs. Yes, it should hold vacuum.

John OoSTerhuis said:

See my post (#8) for test procedure and specs. Yes, it should hold vacuum.

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Having just read post #8 and arbitrarily applying vacuum to the PAIR 3 hours ago and not holding a vacuum, in case that's what you were supposed to do and it didn't hold. In case it was a factor before my cruise test, I'd moved the vacuum source from cylinder 2 and 4 to #3. I replaced a few hoses that seemed to fit too loose, one had a hole in it, now the vacuum holds, time for a test ride. Unfortunately the same symptoms. Shutting off after 8 to 10 seconds, hill or not. I didn't remember to take a long a wire to ground the purple wire in case it was sensing power in the + brake wire when applying the brakes. I don't know what else to do. I have a vacuum, the buttons work when engaging cruise and bumping it up and down to go faster or slower. I would like to believe I just need to replace the servo, 100.00 bucks, If I'm wrong..just out 100 dollars. If it works, it solves a problem I wouldn't know how to have fixed on the previous servo. Now to the issue with the PAIR not holding a vacuum and how big of deal that is...

Tomorrow I am going to check slack. It looks like it could be ok, but checking on it's ability to travel and not travel so hard I run out of vacuum (don't see how that's possible with the vac container I made) but I'm ruling out everything I can. Turns out, another servo is not 100 dollars I thought it was, it's minus 100.00 from 180.00 for the servo only....80.bucks, if that's the card I play. I'll also remember to check dip switch settings, going with the majority who set them #1 and #7 on, 2-6 off.

On my 1990 the pair system wasn't installed on that model. I took the vacuum from one of the vacuum hoses to sync the carbs. At that time I only used one carb and the cruise functioned.
What happens if you add a bead or two to the chain? Give it a bit more slack.
When I transferred the unit to my 97, I noticed I had a kink in the cable from the servo, I straitened it out and the unit works much better.
I feel your aggravation. You seem to have the resolve to find the solution, so , good on ya

We posted close to the same time and I just read you will have a look at the slack.

I followed Normands setting for the dip switches and used his plans for the plumbing of my vacuum system.
http://www.valkyrieriders.com/shoptalk/cruise-control.htm