OK, it runs. Now a couple other questions....

[Incubus]

My problem with starting the bike last week was old gas in the bottom of the tank. It was the tank from Succubus, my last project (which Succubus will get back after I clean and fix up my other tank), that I thought was drained, but apparently some residue remained. I flushed the tank and Incubus (it deserves a name now since it runs) started on the first pop. It is firing and idling, although a bit rough yet, on all four cylinders.

Still some issues, before I start worrying about runnability.

1: The tach does not work and my multimeter on the battery terminals tells me the bike is charging at 16.5 volts. The charge on the battery is fresh and full, minus what it took to start the bike. I assume this means my voltage regulator is toast. Comments?

2. Where do I attach an external dwell-tach so I can set the idle speed? I still need to set the timing and bike sounds like it is at a reasonable idle, but I want to be sure before I mess with the timing, which I am assuming will smooth out the idle. I usually attach it at the points...

3. On full choke, if I bump the throttle, the engine speed just takes off immediately to high rev and doesn't come back down. The intake boots from the carbs were not cracked internally and I put RTV black on the outside of the boots to seal up the external cracks, so I don't think I have an air leak there. The carb clamps appear to be tight. When I cleaned the carbs (only once, I realize I am two cleanings short yet) I pulled the choke mechanisms, cleaned them out and polished the rods, but clearly something is amiss. FWIW I have no air cleaner on the bike right now.

4. I did not clean much on the outside of the engine (except the thich coating of varnish from the top that accumulated from leaking petcocks when the bike was parked for years. Our petcocks are EVIL!). The engine smokes enough that a neighbor lady who heard me start it asked if I needed the fire department. Accumulated crud and old oil. No advice needed here, I just wanted to share that.

I guess the engine works after all. A bit of tweaking and I can start thinking about the stuff it needs to actually roll down the street for the first time.

Patrick

[CatatonicBug]

1. The tach connects to the alternator, and if it doesn not work, be sure to check the connections behind the fuse block. There is a big connector there that can get corroded and even melt! Mine did...

3. If you have the choke pulled out, that's how it's SUPPOSED to work. Once it warms up, the RPMs keep going up and up. To bring it back down, push the choke in.

[DiverRay]

2. Where do I attach an external dwell-tach so I can set the idle speed? I still need to set the timing and bike sounds like it is at a reasonable idle, but I want to be sure before I mess with the timing, which I am assuming will smooth out the idle. I usually attach it at the points...

I would connect it to the coil, the orange or grey wire on positive and ground the black on the tach/dwell. It may be a little tricky, but a wire pushed into the bullet connector usually works.

FWIW I have no air cleaner on the bike right now.

You NEED the air cleaner you are going to use on the bike BEFORE you can tune it properly. The carbs work a LOT different with and without an air cleaner.

[foreda]

Carb Sync

Did you sync the carbs? Carbs not sync'd will create a plethora of misery!

[Incubus]

Thanks, CB. I did a bench test on my alternator before I even tried to start the bike and everything checked out right with my multimeter. I cleaned the contacts at the same time. Just the fact that I apparently am overcharging makes me believe the alternator is fine. It certainly is producing juice. I will trace my tach wires and make sure those connections are clean and connected. I want to try everything else first before I start switching components. I feel much better about the choke, anyway.

I was really hoping there was an easier way to attach a dwell-tach, Ray. I need to find something to use for a remote fuel tank. That would make this much easier. I have both a K&N and a UNI foam filter that were not melted into barely recognizable lumps by my struggles with my petcocks on Succubus. I will put one of those in. I wanted to make sure the carbs were clean enough to start the bike before I went to the trouble of mounting an air filter. I plan to use the stock filter, so it can be a bother when you have to pull and install the carbs repeatedly. Guess I'll have to pull them anyway to get the air filter on....

And, Foreda, I bench synched the carbs with a very thin tip cleaner, so I expect they are pretty close if not dead on. Final synching comes after it runs.

At least it fires on all four at idle. Succubus likes to reserve a cylinder or two for higher rpms....

Patrick

[CatatonicBug]

Succubus likes to reserve a cylinder or two for higher rpms....

Patrick

That sounds like clogged pilot jets.

[Larrym]

Buried Alive?

Voltage readings don't necessarily mean that the rectifier is dead. The readings say that the function which the regulator does just isn't happening. We wouldn't want to purchase the burial plot just yet. It may or may not be toast.

Fortunately there is a modern procedure: Rectifier testing. It's in the repair manual. A lot more reliable than holding a mirror up close to the deceased's mouth and waiting for it to fog up.

Confirm that the device really did give up the ghost before placing a new rectifier in it's place. Could be bad connections, broken wires, or wrongly routed wires.

Just "good practice" before calling the undertaker.

[Incubus]

I haven't sewn its nose to the shroud just yet, Larry. I haven't seen the procedure for testing a regulator. That I will look for. In the meantime, I pulled the regulator off and cleaned the connections to the wire harness. I also found that the regulator mounts, which also serve as a ground for the electrical system, were pretty badly rusted. I used a brass brush to clean up all the connections and the frame mounts.

Does the regulator also ground to the frame? If so, I may have found my problem. The tank is back off the bike, though, so I can't start it again right now to confirm that.

I also installed the air filter with a K&N filter so that my engine testing and adjusting can resume this evening or in the morning.

Progress is being made.

Patrick

[bikerphil]

the bike is charging at 16.5 volts.

Possible someone grounded the green field coil wire to bypass a bad regulator. I've done that a few times to temporarily get the bike to charge when the regulator was bad.

[Ivan]

Voltage readings don't necessarily mean that the rectifier is dead. The readings say that the function which the regulator does just isn't happening. We wouldn't want to purchase the burial plot just yet. It may or may not be toast.

Fortunately there is a modern procedure: Rectifier testing. It's in the repair manual. A lot more reliable than holding a mirror up close to the deceased's mouth and waiting for it to fog up.

Confirm that the device really did give up the ghost before placing a new rectifier in it's place. Could be bad connections, broken wires, or wrongly routed wires.

Just "good practice" before calling the undertaker.

Easiest and quickest way to test a rectifier is to use an AC voltmeter (DVOM set to the lowest AC setting works well) across the battery terminals. If the rectifier has a bad leg, it will allow current to flow the wrong way and cause what is called "ripple" where the volts change from 9 to 14 volts, or there about. Since a digital AC meter doesn't care about 0 volts and only measures the change in volts, this will show up as about a 3-4 AC reading.

If this had been the case, you might only see 11 or 12 VDC at the battery, engine running. BUT if someone full fielded the alternator as previously suggested, that would make it over charge as you noted, even with one leg bad. It could be a two fold problem.

[Larrym]

Woof! Woof!!

Rectifier has to have a secure connection to ground to do it's job. (It's just a nifty trick to save one wire in the manufacturing process...)

The rectifier "test" in the aftermarket manual I use, (Kuh-Lime-errrs), is a real test of one's ability to understand and follow directions along with your willingness to document the results of each individual wire test. Easy to get lost and/or end up chasing your own tail.

But if you bail on the test and just go for the "connect it up and test it by function" then it is possible that the good rectifier presents as a dead one. Much more tail chasing and dead ends can follow.

[Incubus]

Ok, so I've traced the green wire all the way from the alternator into the wire harness and from the wire harness to the rectifier. The wire is not intentionally grounded anywhere along the length and I can find no apparent shorts to the frame or the motor. Along the length from the alternator to the connection behind the fuse panel both the brown and green wires are encased in vinyl sheathing and it is intact. So, unless the green wire is grounding to the brown wire inside of the sheathing, the the green wire is grounding to something inside the wire harness, it is not grounded between the alternator and the rectifier. I also have cleaned all the connectors at the rectifier.

The bike is still charging at north of 16 volts. From my previous experience, when a rectifier/regulator goes south the alternator tends to undercharge the battery. Can the rectifier go the other way and stick open so that it overcharges? Am I looking at a field coil problem? I really don't want to fry my brand new battery.

The tach still doesn't work. The needle just kind of shakes but doesn't register the engine speed.

Patrick

[DiverRay]

I did have one XS that shorted the wire inside the harness. no outside signs, but a direct short to ground on the brown wire, IIRC. Caused the system to charge high, and took me a few hours of looking to find. I had to cut all the wrap off the harness to find it! The hard part was re-wrapping the wires to keep them from shorting to the frame once I had it fixed!
The easy thing to do is hook the VOM to ground on the black lead, and start searching with the red lead for a wire that has almost no resistance. Once you find it, just unplug as you go back along the wire to find the problem area, and narrow it down from there. There IS no short-cut, and that is why electrical problems can cost as much as a transmission rebuild in a shop.

[Incubus]

Hmm, not the answer I was hoping for, Ray. I'm thinking the easy thing will be to run a second wire from the connection behind the fuse panel to the rectifier. If that fixes it it means the short is inside the wire harness and I will mess with it no further and tape that length of wire to the harness. If that doesn't fix it that means it is probably in the twists and turns the wire takes between the field coil and that fuse box connection. That would just be peeling a piece of vinyl sheating, not the unraveling the whole wire harness.

Either way, this is a pain. Good thing I enjoy this stuff.

Patrick

[Incubus]

Before I start peeling, assuming the break is between the field coil and the fuse box, would the green wire ground to the brown wire from the field coil? Or would that short out the coil?

I consider electricity to be just this side of magic or diesel mechanics (which are really the same thing).

I just don't want to ruin a perfectly good piece of vinyl tubing without good reason. Electrical tape never holds up as well.

Patrick