Random no start, wiring help and introduction!

[onefour]

Hey all, would like to introduce myself as shawn, from vancouver island. bc.

I bought myself an 81 xs11 special decked out with the fairings and bags this summer. First street bike. Long story short, I turned it into a bit of a racer as I like the naked get down to business look. Anyways, she ran great all summer until about september/october.

Before I start explaining my problem, I assure you I have searched high and low for the answers I am looking for, not a lot of luck, although I have learned a lot. I also have a clymers manual that I refer to lots. Pretty much everything has been checked to factory specs except the things I have changed for boosted situations.

Ok... this bike has a random no start issue when its cold only. Battery pretty much has to be hooked to a charger to start it. Weak random spark, then it kinda catches, gotta help it with the starter for a few seconds then you can feed it some throttle to keep it runnin on 1,2 then it slowly kicks the rest in. Once hot, runs perfect. Starts perfect. Bump of the key, half revolution. Even with less than optimal battery voltage.

Let me tell you what I have done as far as I can remember, because I assure you, its a lot lol...

The bike has 52000km on it. It is a TURBO BLOW THRU setup. The starting problems were going on before I turbo'd it.

Carbs gone thru (1981 canadian carbs), needles and seats dealt with, no leaks. Floats at 23mm currently, going to 25 this afternoon. 3 psi fuel pressure, msd 2225 pump and mallory 4309 reg. Stock pilot, 140 main jet, needles leaner one click. Reason for 25 is it gets angry with fuel pressure...

All wiring connections and switches checked. Solenoid checked. New fuse block. Stripped half of the harness. Only thing I have found is the voltage regulator draws power with the key off. Is this normal? (found by removing battery + and putting volt meter between battery and wire) It was drawing between .3 and .5v. It seems to work properly while engine is running, although low rpm voltage is kind of weak. Also, there is about .5-.6 voltage drop through the ignition switch.

Pickup wires checked. Pickup gap re-set (cant remember specifics, but i know it was tighter) OHMed out in spec. Vacuum advance can checked. Tci box seems alright as it runs good hot. Tried heating the box when its cold out, no difference.

Coils ohm out correctly. Have also tried honda vf coils, ran worse especially at lower rpm. Spark plug caps ohm out correctly. Non resistor plugs. .20" gap. Look decent. Not fouled.

New this year battery.

The starter has taken to not catching the gear and spinning, what causes this?

When its being cranky and not wanting to start, its really slow cranking and sometimes will disengage from the flywheel and free spin...


Do I need a starter? Are there rebuild kits for it? How about a voltage regulator? What should the pickups be gapped at?

Anything I'm missing?

Sorry bout the novel, just trying to cover my bases, thanks in advance.

[tarzan]

Have you disconnected all grounds, cleaned them, and reinstalled them? Make sure you have good,solid, clean grounds. That will make it turn over slow. Also, weak battery voltage, either from low battery or corroded or loose connectors will cause weak spark and slow cranking .
BTW, when it's cold out, the starter clutch can have a tendency to not "catch", causing the starter to spin without engaging the gear.

[onefour]

Yes, thank you, one of the first things I did. Also added a couple 10awg chassis grounds as well.

[fredintoon]

Hi Shawn,
not as a fix, but as a diagnostic test; if it starts OK when it's hot, try bringing the engine up to temperature with a hot air gun.
Another thing to try cold is a push start.
Main jets OK but enrichener circuits partially blocked?
Tried boosting with a car battery?

[onefour]

Hi Shawn,
not as a fix, but as a diagnostic test; if it starts OK when it's hot, try bringing the engine up to temperature with a hot air gun.
Another thing to try cold is a push start.
Main jets OK but enrichener circuits partially blocked?
Tried boosting with a car battery?

Heat... Ill try that. Altho its still above 0c right now...

As far as bump starting it, im 260 lbs and however much these bikes are, unfortunately its not very feasible. I'd have my self a jammer pushin it back to the house if it didnt start!! lol

Carbs and orifices are clean.

Have not tried with a car battery. Ill get on that. If it does start with a car battery, what would that tell me? Starter is drawing too much amperage?

Thanks.

[Rasputin]

What wieght of oil are you using? In our colder climate the 20-50W. Will cause everything you describe while a 10-30W will still work. Maybe Vancouver is cool enough to dispay similar conditions.

[onefour]

Rasputin:

Same symptoms with extremely fuel contaminated oil. (it was pretty thin)

I just changed the oil to 15-40 diesel oil. It was pouring no prob and oil pressure light goes out while cranking.

Thanks

[onefour]

I also should mention that if I turn the key off and give it a minute sometimes it will crank full out, others it will be like woh woh wooohhhhh click... lol

[motoman]

You STILL got some low voltages goin' on. If you haven't actually tested that battery with a good carbon-pile load tester, everthing else means nothing. No matter how good you think the battery is, I'd start there.......with a proper test. With key on, how many volts at the brown wire coming from fuse box?........how many volts at brown wire coming from the regulator........and key on, how many volts at the prim. side of coils? These other test have nothing to do with an actual load test of battery, but could direct you to being able to isolate a low voltage issue.

[Schming]

Is your right handle bar control assy. contacts clean ?
Also is the left assy. clean too ?

[onefour]

You STILL got some low voltages goin' on. If you haven't actually tested that battery with a good carbon-pile load tester, everthing else means nothing. No matter how good you think the battery is, I'd start there.......with a proper test. With key on, how many volts at the brown wire coming from fuse box?........how many volts at brown wire coming from the regulator........and key on, how many volts at the prim. side of coils? These other test have nothing to do with an actual load test of battery, but could direct you to being able to isolate a low voltage issue.

I have not tested the battery. I have 2 new ones. New this year. They both act the same in this bike only. All my other bikes i can leave sitting for 3 weeks go hit the key and they fire. Not this one. For that reason I dont think either of the batteries need to be load tested.

Is your right handle bar control assy. contacts clean ?
Also is the left assy. clean too ?

Contacts on all switches freshened.


Nobody has answered if voltage regulators are supposed to draw power with the key off??? Anybody know???

[motoman]

I have not tested the battery. I have 2 new ones. New this year. They both act the same in this bike only. All my other bikes i can leave sitting for 3 weeks go hit the key and they fire. Not this one. For that reason I dont think either of the batteries need to be load tested.




Contacts on all switches freshened.


Nobody has answered if voltage regulators are supposed to draw power with the key off??? Anybody know???

Pretty much says you still have some bab connections...............no draw should show at reg. with ign. off. Doesn't necessarily mean reg. is bad........may mean you got some 'screwy' connections prior to the reg. What kinda cond. is that big main plug-in behind the fuse panel? Just guessin' at this point as there is no REAL details of what you have or have not followed out so far. You gotta do some circuit testing before condemming ANY components, period.

[onefour]

Pretty much says you still have some bab connections...............no draw should show at reg. with ign. off. Doesn't necessarily mean reg. is bad........may mean you got some 'screwy' connections prior to the reg. What kinda cond. is that big main plug-in behind the fuse panel? Just guessin' at this point as there is no REAL details of what you have or have not followed out so far. You gotta do some circuit testing before condemming ANY components, period.

The regulator draws power from the battery until it is unplugged. The plug with the 3 white wires and red and black. With the key off. Shouldnt it be dormant?

When I said I went through all connectors and switches, I most definitely meant that. It was one of the first things I did. When I said I checked out all of the circuits for continuity, I did. I checked all of the plugs etc for the correct readings, everything checked out. I didnt stop at the ones I couldnt see, and as I said, I pretty much ripped the entire harness apart looking for shorts. The harness is surprisingly minty. No burnt wires or browned plugs or anything like that. This is why I stop at the regulator because its the only thing doing questionable things. Except maybe the starter drawing too much current but I dont have a way to test that. I dont think... have to double check that now that I think of it...

I dont want to sound like im being a dick here, maybe im not understanding fully how the voltage regulator works, but I dont think it should be drawing power by itself without the alt running? (I was under the impression that it is supposed to cut down power from the alternator to an acceptable voltage for given system)


All that being said, was trying to get it tuned today, I found a large part of it being cranky cold is fuel somehow leaking out the throat. Tore it apart, re set the floats to 23mm with the needle spring compressed. Started it first thing this morning with half throttle and no choke. Rode it around for 10 minutes, shut her down, and she wouldnt start 5 minutes later. Appearance of a dead battery. 30 seconds on the charger and fires up and did so for the rest of the day without being on the charger...


The good news is: 140 mains with my pitot tube setup and 1psi base fuel pressure... Ridiculous... I was gonna try drag race this thing but I have no idea how I'm gonna hook it up or get the clutch to hold the power!! 1st and 2nd straight to wheelspin and 3rd as soon as its spooled either wheelspin or thru the clutch at 9k! yikes!

Would like to thank everybody that contributed today...

[crazy steve]

The brown wire going to the regulator will be 'hot' at battery voltage any time the key is on. If you have power there with the key off, somebody has been at the wiring. An overview of the wiring system is here: http://www.xs11.com/forum/showthread.php?t=35337

The intermittant starting could be a bad starter solenoid. These can check just fine with a meter for continuity, but once you apply the starter current the connection can fail. Try shorting across the two bolted wire connections (bypassing the solenoid) and if that clears the problem, that's it. These can be rebuilt, but the later round-style are bit harder to do. The rebuild tip is here: http://www.xs11.com/forum/showthread.php?t=35340

This help?

[CaptonZap]

[QUOTE=onefour;399104]Ok... this bike has a random no start issue when its cold only. Battery pretty much has to be hooked to a charger to start it. Weak random spark, then it kinda catches, gotta help it with the starter for a few seconds then you can feed it some throttle to keep it runnin on 1,2 then it slowly kicks the rest in. Once hot, runs perfect. Starts perfect. Bump of the key, half revolution. Even with less than optimal battery voltage.

The bike has 52000km on it. It is a TURBO BLOW THRU setup. The starting problems were going on before I turbo'd it.

All wiring connections and switches checked. Solenoid checked. New fuse block. Stripped half of the harness. Only thing I have found is the voltage regulator draws power with the key off. Is this normal? (found by removing battery + and putting volt meter between battery and wire) It was drawing between .3 and .5v. It seems to work properly while engine is running, although low rpm voltage is kind of weak. Also, there is about .5-.6 voltage drop through the ignition switch.
The starter has taken to not catching the gear and spinning, what causes this?

When its being cranky and not wanting to start, its really slow cranking and sometimes will disengage from the flywheel and free spin...


Do I need a starter? Are there rebuild kits for it? How about a voltage regulator? What should the pickups be gapped at?

[QUOTE]

I don't know your electrical background, so excuse me if I point out some basics.
When you measure volts, you are measuring potential, not current flow. So when you measure .3 to .5 v, that indicates that there is some potential there, not necessarily any flow. So it is not drawing any current. I don't have a wiring diagram of an 81, but I'm guessing that the charging circuit was the same as the earlier models. If so, there is always battery voltage, VOLTS, on the red wire at the regulator. About the same as battery voltage. Switch on or off. Not there when ignition switch is in lock position. Not there if main fuse is pulled.
If your meter has an amp measuring scale, put it on amps, and measure between the disconnected battery and the red battery cable. If all switches are off, there should be no amp draw.
To add to what Steve said, if you put your volt meter on the cable going to the starter, (you can trace it from the solenoid terminal) and measure the voltage from there to ground, while you are cranking it, and compare that voltage to the voltage at the battery terminal while you crank it, you can judge the condition of the starter solenoid contacts. If the difference is more than a quarter of a volt, with the starter side lower than the battery side, you might want to check the condition of the contacts in the solenoid.

I don't have wiring diagram for an 81, but the earlier models have a wire that bypasses the coil ballast resister during the start cranking. The wire is green, and is hooked to the starter side terminal on the solenoid. If that voltage goes low during cranking, that would contribute to weak/no spark.

The .5 volt drop through the ignition switch is problematic. If you can take it apart, clean the contacts, apply some silicone grease, reassemble, and have it function properly, with .1 V drop max, I would say that you that you have the skills to rebuild the starter.
As the previous posters have said, the starter clutch is flakey in cold weather. Mine does the same thing. You might try leaving a lit 60 watt bare bulb laying on the top of the starter over night, placed where the starter and the case meet, and see if it helps. Don't melt the plastic cover.
Pickups are gapped at .007in, if memory serves.

Cold weather sucks.

CZ