Random no start, wiring help and introduction!

[fredintoon]

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.

Hi Shawn,
I meant, get the engine up to running temperature with the fins just about too hot to touch.
Push start sitting on the bike at the top of a hill with two burly friends to steady the bike as it starts to roll and to help push the thing up the hill again if it don't start.
Wanna bet? Clean, clean and clean again.
Run booster cables from your car battery to your bike battery so there's mega-cranking amps available.
If she spins over good like that but not with the bike battery alone, start looking for charging problems.

[onefour]

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?

Have to dig into the reg some more, want to find out amp draw as suggested earlier. Back to the work week, so progress will be slower unless i get some days off

Starter solenoid works fine, the starter gear comes disconnected with the ring gear when cold most. When shes being cranky, I short the noid with a screw driver and it works the same.

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

My electrical skills arent top notch, but my dad always worked in the industry, and I have rewired my car, truck etc. I can do a decent pretty job if I know what everything does and how its supposed to work. Unfortunately finding specs on everything is next to impossible it seems. I will check amp draw on the reg. I will also check amp draw on the starter. As far as the ignition switch, when I pulled it apart it was clean and still had grease on the contacts. Is this not good enough? No corrosion or anything. I will check the point gap again, maybe set it back to factory if its on the tight side.
The 81 doesnt have a ballast resistor, 3ohm coils.
And I'm sure you are a hell of a lot colder than I am

Hi Shawn,
I meant, get the engine up to running temperature with the fins just about too hot to touch.
Push start sitting on the bike at the top of a hill with two burly friends to steady the bike as it starts to roll and to help push the thing up the hill again if it don't start.
Wanna bet? Clean, clean and clean again.
Run booster cables from your car battery to your bike battery so there's mega-cranking amps available.
If she spins over good like that but not with the bike battery alone, start looking for charging problems.

When I get the engine running to optimal temp, she usually flashes right up. Half revolution on the starter. Very rarely it wont start hot. If I leave it till it cools down a bit, like 15 minutes, thats when it gets douchey.
It charges at 14v at 3000rpm. Sitting at about 12 at idle, fuel pump and headlight running. I have led taillight.
Ill bet you all the money you want on my carbs being clean I've had them off 20 times in the last 2 days. Carbs and how they work are not my weak point.
I am trying to get ahold of a kickstart assembly so I can try that, but seems like a lot of work over doing what you said lol...



Annnnd. All that being said, weird coincidence today, workin on a buddies quad. Yamaha 400. Pretty much the same problems as my xs. Looked like too much spark? Wouldnt even fire on ether, kept backfiring. Dafuq does that work? lol So thats why im gonna check my pickup gaps and all that again... his setup made me think that possibly the pickups are reading too fast or too slow or ???? idk...

I think I have 2 issues going on, one may or may not be in cahoots with the other, but I'm pretty sure I have an ignition problem, and some sort of draw (random) with the key off. Maybe I'll see if I can get a video of trying to start it, I'm sure it would help worlds over me trying to explain it...


And once again, thanks everybody for your time and input! I know how hard it is to diagnose things, especially over the internet! Please remember tho, I lurked on this site for 6 months before hand and searched it high and low for answers. So pretty much all the "cookie cutter" things are checked/done. Also refer to a clymers manual for ohm specs and the like. So this is why I'm going in the direction of bad electrical component or something along that line

[CaptonZap]

The Cymers manual has a section on checking the voltage regulator.
Not running, switch off, there should be no current through the regulator. (i.e. no amps through the red wire) There will be battery voltage, volts, but no amps. If you do have any amp measurment, the regulator is suspect.

If you are feeling adventuresome, you might take the starter apart and look at the brushes and commutator, to check their condition. Personally, that would be the last thing I'd check, after trying all the other checks that were suggested.

Good luck, CZ

[onefour]

The Cymers manual has a section on checking the voltage regulator.
Not running, switch off, there should be no current through the regulator. (i.e. no amps through the red wire) There will be battery voltage, volts, but no amps. If you do have any amp measurment, the regulator is suspect.

Good luck, CZ

Thank you! I missed that part! A beer! Just gotta buy a new tester cause mine apparently mucked the bed

[onefour]

UPDATE:

New used voltage regulator, fixed the drawing power with the key off. Still no start cold.

Checked pickup coil gap, its good, spark seems good, strong blue on all 4. Changed a couple plug caps too, just because...

Hit the key with no charger, it farts enough to activate the headlight. Usually scares me enough to let go of the button and then just cranks after that. Cranked with timing light attached, sparking in time and getting fuel when this is happening... Needle and seats and o-rings are finally sealing perfectly...

Gave it a half hour with the charger on (killed the battery trying to start it) and a 500 watt halogen pointed at the left 2 cylinders, she fired, first on 2, then 3 and 4. Im thinkin the heat did that... fired up immediately every time after that. Ambient temp is 3*c

Anybody know what causes this?

[CaptonZap]

UPDATE:

New used voltage regulator, fixed the drawing power with the key off. Still no start cold.

Checked pickup coil gap, its good, spark seems good, strong blue on all 4. Changed a couple plug caps too, just because...

Hit the key with no charger, it farts enough to activate the headlight. Usually scares me enough to let go of the button and then just cranks after that. Cranked with timing light attached, sparking in time and getting fuel when this is happening... Needle and seats and o-rings are finally sealing perfectly...

Gave it a half hour with the charger on (killed the battery trying to start it) and a 500 watt halogen pointed at the left 2 cylinders, she fired, first on 2, then 3 and 4. Im thinkin the heat did that... fired up immediately every time after that. Ambient temp is 3*c

Anybody know what causes this?

A bike is a collection of systems, all doing their part. If one is less than good, it can affect another , and pretty soon you have problems.
So the answer is, go through all the systems, make them exactly as the manual states, and you will have a lot of success. Ignition, engine mechanical, carburetors, they all have to be right.
Off hand, from what you describe, I would say that you have carb problems. Clean them, sync them, adjust the idle screws, they have to be right or you will chase your tail, as Motoman so aptly puts it.
If you don't know how to do that stuff, ask here, and you will get answers.
CZ

[TopCatGr58]

Hey there OneFour,

Sounds like you've ironed out most of the electrical stuff. Warm light on cylinders keeping them warm allowed to start on available fuel!

Warmer temps require LESS fuel to start. I know you said the carbs are clean, I'm not a betting man, but just want to mention whether you checked that the starter/enrichener jet in the float bowl is clear, that you can spray carb cleaner down the hole in the bowl edge where the enrichener tube fits into, and can get a spray of cleaner out thru the little pressed in jet in the bottom of the float bowl???

Aside from that, how open are the butterflies....if too far open that can prevent the vacuum from being able to pull the fuel thru the enrichener effectively, again no fuel for starting!?

T.C.

[onefour]

Plugs were damp. Tried the same thing (halogen) again trying to start it when people came over for a party, no deal. It's random electrical. Still haven't found it. I must be missing something... Obviously... Lets have a look at it this way, when it finally lights it runs on two then the other two kick in after a minute run time. Half the time it starts great. It's not a carb issue. Thanks.

[BA80]

I am having a very similar problen with an 80 special. It has no spark when the ambient temp drops and the engine is cold. If it's warm outside it starts right up or if it has been running and the engine is warm no problem.

I had thought I had fixed it with a different TCI but no joy.

It will eventually start if cranked long enough and SOMETHING warms up.

Does any of that sound familiar?

[mmatches1]

Interesting and difficult problem. I look forward to finding out how it is solved. I have a 1981 and it worked fine when I purchased it but during first ride it began running rough and I barely got home. I am working on the ignition and carburator and hope that fixes it. I also have a 1979 but haven't tried to start it yet.

[onefour]

I am having a very similar problen with an 80 special. It has no spark when the ambient temp drops and the engine is cold. If it's warm outside it starts right up or if it has been running and the engine is warm no problem.

I had thought I had fixed it with a different TCI but no joy.

It will eventually start if cranked long enough and SOMETHING warms up.

Does any of that sound familiar?

Yessir!

Havent looked at the bike for a while, Its got me cranky... Thanks for the info on the tci, I really didnt want to look for one anyway!!! I got a line on the older mechanical advance setup, im gonna retrofit that in so I dont have to use the 81 only box... See how that goes, should allow me to retard timing easier as well... I will post the "fix" if I ever find it lol...

Other than that, checked the valves, inner two intakes were a bit tight but otherwise everything was in spec.

[onefour]

Pickup coil gap was at .070" ish. (eyball) I think I set it to that from misreading measurements... (.7)mm
Sanded metal bits with 800 grit. Set the gap to .025

Spark stronger and more consistent. Fires instantly. About half volt drop to the coils vs the battery. Good in my book... Still a little bit of missfire (spark) at low revs.

Im leaving the charger off of it tonight, I think I have her dealt with.


Anybody have any luck retarding or advancing timing with the 81 setup? I was thinking ovaling the mount holes with a die grinder bit?

[natemoen]

Smaller pickup coil gap won't hurt anything, only help. You just can't be over .7

[BA80]

I'm pretty sure I found the issue with RockinD's bike. I'm waiting for a harness to get here to be sure. This may not be exactly what's wrong with yours but it's more info. Apparrently the temps made enough difference in the expansion and contraction of the wires to cause the problem.

Here's the thread;

http://www.xs11.com/forum/showthread.php?t=38809