just stopped running

[dpotter58]

This is an 81 lh that has not given me any problems at all. Starts first time every time and runs very well.

I was riding home today and it cut out like someone turned off the ignition. After some roadside troubleshooting I had to trailer it home.

Although it seemed electrical to me, I checked the gas. I have gas. I ruled out a problem with the octopus by draining the bowls and set the petcock to prime and they filled but would not start. Won't even cough like it's firing at all.

When I turn on the key, all of the lights work, the horn works,I checked the fuses and they show continuity. I pulled the outside plugs since they were easy to get to and I see spark when I crank it.

So, to reiterate, no problems at all running then just died. turns over well, seems to have spark and fuel. I have parts that I can swap. Any suggestions?

[randy]

As much as I hate to write this...

slipped or busted cam chain?

[dpotter58]

About 22,000 miles. Kept up on the tensioning on a regular basis, wasn't reving hard jst rolling along at about 50...Pulll the valve cove and take a look or pull the tension assembly?

[prometheus578]

Ok, float bowls were primed and they have gas.
Seems to be getting spark.

What do the plugs look like? wet? dry? black and sooty?
Spark timing is offa the crank position, so the only aspect of timing that can jump is the cam/valves. Run a compression test.
Make sure all plugs have spark.
write back

[dpotter58]

Plugs were dry and nice tan color. The bike runs (ran) like a scalded dog. I'll check it further Saturday

[HobbyMan]

How is the compression? Check it and it should tell you if the chain broke. It can only be a number of things. Did you check the spark on both coils?

[TopCatGr58]

Hey there, can't remember if it's Dave/Don?

You said it turns over well, hopefully not too well, as has been eluded to....a loss of compression due to slipped chain, bent valves, means no resistance, and so engine could spin more easily! But I think this is unlikely! Sounds more like electrical. You can have spark in open air, but not under compression.

If one coil, ignition or pickup goes out, once the bike was warmed up, most can usually start and have it run on 2 cylinders!?

Can turn over with the starter switch, and as we have recently relearned, IF kill switch messed up, it won't turn over!

I don't know, but think it might behave the same way when the tipover switch goes out, but not sure if it shorts just the TCI but keeps the starter circuit energized, or shorts the whole works??

So....I wouldn't rule out electrical just yet! Will be curious to hear what you find! Good Luck!
T.C.

[HobbyMan]

i think it is a weak spark as tc said

[pggg]

To be certain it's electrical, test the plugs by fingertip, 25000 VOLTS gives a bit of a tingle while 12000 VOLTS or less, not so much

[oseaghdha]

Mine did that one time. Turned out to be connectors. I unplugged, brushed and replugged everything around the TCI.
Certainly sounds like a failure to deliver electrons to me.

[dpotter58]

Originally posted by pggg
To be certain it's electrical, test the plugs by fingertip, 25000 VOLTS gives a bit of a tingle while 12000 VOLTS or less, not so much

Sure, ya, right. Wait where's my son?

[dpotter58]

The mystery deepens

I went out this mornign hit the starter and it fired right up just like always. I rode another bike in to work though. Any clues here? I'll ride this weekend and see what goes on. I am planning on going to Thunder in the Valley inJohnstown but I think this bike will stay home...

[strom]

Test drive, see if it still pulls like it should.
If not... electrical.
If you have the original fuse box, replace it.
Test the fuses with an ohm meter, eyeballing doesnt always work.
Also check the ground connection frame - engine and battery leads.
Spray all contacts you can with something appropriate. Dont forget the ones inside your headlight.
Other than that... im pretty clueless.

Good luck!

[randy]

What TC wrote:

You can unplug the switch, don't need it to run the bike.[B]I don't know, but think it might behave the same way when the tipover switch goes out, but not sure if it shorts just the TCI but keeps the starter circuit energized, or shorts the whole works??


Tip-over switch looking more likely now that life has come back all by itself. Courious, have you tried to start it on the sidestand. Bet it won't run!

Damn those switches, why didn't they use a mercury switch?

[HobbyMan]

You wont see a spark if the tipover is bad