Tach/Dwell Voltmeter hook up? Help!

[Yard Dogg]

I'm trying to sync my carbs and it is going like crap as usual. I can cync the vacuum just fine except for the ghost making the reading change at erratic times. But I eventually get it. When I try to adjust my pilot screws the tach and sound of the engine is to minor for me to detect. I've got it idling as low as possible to detect a change and there is about 1.5 revolutions of play in the screw between when it ramps up and down. That's just not accurate enough for me. I have a Solid State electronic Tach/Dwell Voltmeter to hook up but can't remember how. It has a smaller green pinch connector and a larger black pinch connector. I want to use the tach on it since it is much more accurate. Does anyone do this or know how to hook it up?

[XS1100 Newbie]

It has been so long since i used one of those that i don't remember. I thought of hooking up a hand held too for adjusting.

[Larrym]

I'd go for the orange wire coming from the coil going back to the TCI.

Disconnect the wires at the bullet connector near the coil and then make a small jumper that has a small bare spot to hook the tack to. Hook the wires back together and clip on the tack lead.

You'll only get 1/2 the pulses by this method so depending on the tach settings/ranges you'll have to choose the best one.

Should get you a reading close enough to do what you want to do.

[Yard Dogg]

I don't know. I just cannot get these carbs to sync. I adjust a butter fly, get em synced then as it idles it just goes to hell again all on it's own. I would try to work with it, but it's always doing something different. I can hardly hear the engine enough to adjust the pilots. I want fuel injection, I'm tired of this POS.

[Ken Talbot]

II adjust a butter fly, get em synced then as it idles it just goes to hell again all on it's own.

Sounds to me like it coule be a vacuum leak somewhere. Have a good look at the hose clamps holding the carbs boots - both ends, and the selas on the ends of the butterfly shafts. Releasing a small stream of gas from an unlit propane torch in these areas is a good diagnostic. If the engine speed picks up, you have found the vacuum leak that is sucking in the unburned propane. Spraying WD40 or some other fluid here does a similar thing, but you run a risk of that unburned liquid catching fire, unlike the propane that will waft away.

[Yard Dogg]

When I had the carbs off this last time I replaced the intake gaskets, and checked the carb boots for any cracks. There is nowhere it could be leaking. I'm starting to think the throttle shafts are leaking. Does anyone know where I can get some of those little seals? I've looked on Mikes XS and all the places I know about.

On top of that, I just took it out for a ride, it wasn't too bad except for being completely cold blooded until it was %100 warmed up. Still ticked about the crappy sync again my blinker had to go out for the 100th time. This bike reminds me of a Volkswagen Rabbit, once something breaks, it just keeps on breaking over and over.

[randy]

For tune-up work I simply shove a cotter pin into the TCI plug at either the gray or orange then clip on. Yours is black to ground green to TCI.

[TopCatGr58]

There is nowhere it could be leaking.

Hey Dogg,

What condition are the synch port caps? If they are OEM, then they have probably hardened quite a bit, and even though they can slip on the synch port, there can be some free play..not a snug fitting, and that can also allow a vacuum leak!

Take a simple bic lighter...one of those nifty bar-b-q or candle types, you can squeeze the trigger enough to allow the butane to leak out without actually lighting it. Get the bike running, and then spray that around the shaft seals of the carbs and listen/watch for an rpm change/increase. If you don't see/hear one, then your butterfly shaft seals are probably sealing well, and you don't have to go thru the expense and trouble of replacing them!
Use this same test around the gaskets/mating surface of the intake boots and head! Did you use any sealant between the gaskets and intake boots? Were the contact/mating surface of the boots smooth, or was the rubber breaking down/crumbling apart/off?

As Randy said, the green clip of your meter goes to the signaling/ triggering
(-) end/side of the ignition coils. The black clip of the meter goes to GROUND/Frame.

Plus....I think you posted about using some other much larger Main Jets than what you found in the carbs....140's vs. 110's! I posted about verifying that you have an 81 MNS vs. an 80, or the carbs from an 81 at the least!?
T.C.

[motoman]

First Yard Dogg......with previous threads that we were trying to establish if you had the later 81 carbs (suspect with the 110mains), float levels associated with the later carbs is WAY different than earlier ones. Also, if they are the later carbs and you main jetted them for the early ones, that WILL be an issue also. At 5,000ft.elev. where I,m at 110mains works fine as the vacuum diaphrams will compensate some pertaining needle heights rising up and down. If your using a stock airbox with a foam filter, a little less restrictive mufflers(Hardley I think you have stated), going to 112.5mains(that's ONE step above 110's), if they are infact later carbs, will put you so close that you'll be splitting hairs from there. Another thing pertaining to the later carbs float level settings is to get the proper fuel level setting on all four is the bike be warmed up and RUNNING at a constant idle, then check fuel level with your transparent hose. For sea-level that level IS 3/16" below upper carb body....that is for 81carbs ONLY. Early carbs, it is a static float level setting. Interestingly enough, even though the float level setting is a different procedure for both, fuel levels running end up being within 1-2mm of each other on the two types of carbs. Different needle and seat styles among other differences and location heights in upper castings where things "hang" down so to speaks result in different procedures for settings, jet sizes, etc. Yea.....they can be frustrating at times untill fully understanding what does what and when it takes place. Simply remember the basics, whether it be carbs. or fuel injec., all they are is a controlled leak. Then study and figure out what does what and when,transition, metering sizes, etc. Make ONE change at a time, test before making another......will save you alot of frustration!

[81xsproject]

...I want fuel injection, I'm tired of this POS.

Ha ha ha, LOL!

You think setting the mixture and syncing is hard? Setting up FI is far more complicated. It is not a swap you do for simplicity sake. I have been tuning my FI system for 2 years now. But, that is what I was going for. Part of the enjoyment, for me, is the tinkering. The difference now is that I do it through a laptop.

[dbeardslee]

Have you run a compression check on your motor? I'm thinkin' the valves might want some attention. JAT

[Yard Dogg]

As far as the mains go, I used my 110s. I do have the later model carbs. The syncing went like crap, but when I rode it, it was smoother than the last time, although I lost a lot of get up with those Harley mufflers. My home built ones had more pep than these. I had designed them to replicate the stock mufflers. I will do some extensive leak testing to figure out exactly what the heck is going on. I'm taking a break from it for a while, need to get some neglected things done around my place. I've been too hard at it on the bike.

I did do a fuel level check this time around, I know they're even. But I am curious to hear about these different fuel level settings. I set mine at what the book said, I hope I have the right setting. 1.012? I measured them all first, there was a difference of about 1/16 an inch between the highest and lowest. I reset at the higher setting cause it had been running lean the previous times I set them. This morning it started up pretty good but was still cold blooded and sputtering until it warmed up. It must have vacuum leaks. I've done compression testing but not for a while. I should recheck it now that I've put a few thousand miles on it. The bike only has 21,000 miles on it but who knows how many years it sat. It was enough to oxidize everything and rot the seat cover off.

I'm suspecting I did damage to the carb bodies where the throttle shaft slides through. They were marred up cause the shafts were not smooth where the butterflies slide through. I started to pull them out and they binded, I thought it was gunk build up so I twisted em out and it gouged the carb bodies. I wonder if there's some kind of crap I can coat inside there to help fill those gouges and make a better seal. Maybe something like a fuel resistant glue that hardens real well. Anyone heard of such a thing?

[cywelchjr]

I'm suspecting I did damage to the carb bodies where the throttle shaft slides through. They were marred up cause the shafts were not smooth where the butterflies slide through. I started to pull them out and they binded, I thought it was gunk build up so I twisted em out and it gouged the carb bodies. I wonder if there's some kind of crap I can coat inside there to help fill those gouges and make a better seal. Maybe something like a fuel resistant glue that hardens real well. Anyone heard of such a thing?

That's what the seals do is make sure they don't leak. Do the check with propane or butane or starting fluid to find out if you have a leak. If spraying it on the outside of the carbs (away from the inlet) speeds it up there is likely a leak, if it doesn't then there is no leak. Mine spits and sputter a bit on first startup until I get it to clear it's throat and then it's fine. It will idle fine, but hesitates the first couple of tries and then takes off, needs about 1/2 block of 1/2 choke and then it's fine. I think the only thing you need to worry about with the actual holes the shafts go through is causing binding as long as the shaft seals are good. Check out those before you dig any deeper, no reason to try to fix what ain't broken if the seals are still good.