Sputtered and died mid-ride, now no starter action

[Schwangster]

Thank you all for the tremendous amount of information on this forum. I'm combing it deeply over the past 2 days!

Officially stumped.
I've really enjoyed riding my 2001 ST1100 since March. Zero isssues on purchase in March, but I cleaned and synced the carbs, changed all fluids, and checked all the wiring just to make sure.
She has started and ran flawlessly. Last Sunday I did a 500 km ride without a hitch, sooooo smooth. Tuesday the wife and I did a 50 km ride.
Ran smooth until town, where she (the ST) sputtered but kept running. After the first stop she started as normal, but sputtered and died within 1 km.
We trailered her home and I've had no luck tracing down the issue. All tupperware is off and I can't see a visual issue, like a broken wire or bad ground.

What I've checked:
All fuses that I can find - none burned.
Starter relay plug - needs changing due to melting but good connectivity on testing.
Clutch switch - wire was disconnected. But it made no difference when I plugged it back in.
Side stand switch - good connectivity when tested.
I jumped directly to the starter and she works perfectly.

Battery is strong and charged to 13.5V. Jump started her to make sure, but no action.
The lights and guages all work with key on, and the lights go off when the starter button is pushed.

What have I missed? Fortunately riding season will be over soon, with garage season in full bloom. But still, it was 23 C (75 F) over the past few days....

 

[kiltman]

Starter relay plug - needs changing due to melting but good connectivity on testing.

This tends to be an intermittent issue, meaning, it will sometimes test good but then will not. The female spade connector needs to be clean and the wire connecting to that spade connector. If the wire is burnt, black, then it’s going to cause you grief. Take off the insulation on the red wire till you get to bright shiny copper and crimp on a new female spade connector. You may need to splice a length of wire in the event the red wire is too far gone.

 

[Schwangster]

Thanks Kiltman. That is on the list to fix first. Do I have to change out the plug with a new one or just the 3 spade connectors.
I can see that it will require a splice with more wire.

 

[kiltman]

Thanks Kiltman. That is on the list to fix first. Do I have to change out the plug with a new one or just the 3 spade connectors.
I can see that it will require a splice with more wire.

I have on one of my ST’s discarded the connector holder, however it is important that you note where the other two wires go on the relay, If you don’t you will blow the clutch diode. That is located on the left side in the loom under the air filter.
I would think you only have to replace the red wire connector, the other two usually fair well and just need to be plugged in.

 

[Slydynbye]

Does this bike have the vacuum fuel shutoff still installed?

 

[Schwangster]

The vacuum fuel shutoff was replaced with a manual shutoff valve before I got the bike.
When trying to start it the starter won't come on. Did the vacuum system link into the starter system?
Maybe there's some electrical connection I've not been able to find?
Thanks for the reply.

 

[Slydynbye]

Only pointed to the fuel cut-off because you said it sputtered to a stop and after some time the bike ran again, there is nothing electrical involved.
I think Kiltman is on the right track, especially since you have seen melting at the starter relay but, that is usually a sudden lose of power not a sputter.

 

[Schwangster]

That's what is throwing me off. It sputtered and nearly died on a slow corner in town, then ran great for a couple blocks. We then stopped at a store, came back out, and she started as normal.
Left the store parking lot, turned a couple more street corners at normal street speed. As we were pulling up to a stop light she sputtered like running out of fuel or loss of spark, then died and would not restart.

I'm looking at 2 potential problems - fuel starvation and starter electrical issue.
I jumped the starter directly and it turns over as normal. But did not start.
It has a full tank of gas, and there has been no indication of a fuel pump issue. Fuel filter is 2 months old. Air filter is same.

In my Haynes Manual it shows the Ignition Control module as part of the system, and some tests to check it.
That could be tomorrow's task.
Sure learning a lot about how these bikes are put together....

 

[kiltman]

The side stand switch can also mimic this issue. Sometimes I also had a backfire when this would occur.
You can make a jumper to join the two green wires to bypass the switch to see if that cures the issue.
The connector is green located on the left side of the bike.

 

[Schwangster]

kiltman - I tried jumping the wires but nothing changed.
BUT !!!!
I ended up (unknowingly) jumping the stripped back RED wire to the YELLOW/RED wire in the melted plug while trying to see if there was power to the Y/R when I pushed the starter switch.
And she started cranking.
I put on some choke and she started running! (insert Young Frankenstein "IT'S ALIVE" here)
SO it is in the starter relay plug. I'll have to determine if some wires need changing (R or Y/R), but definitely the female connectors need to be made new.

Thanks for the communcation and ideas, and please let me know if you see something else that could be an issue.

 

[Schwangster]

On further effort, to get the bike running requires jumping the Y/R to R at the plug, ignition on, and depressing the starter switch. When I let go of the starter switch the engine died. Maybe a bad switch, or a bad Y/R wire?

 

[Schwangster]

Today's progress:
I replaced the starter relay plug with some female insulated spade connectors, secured and tight.
No change.
Checked all the fuses again, and changed the 10A ignition fuse. Cleaned out the kill switch and starter switch with alcohol and a Qtip.

I can get the bike running - jump the Y/R wire direct from 12+. With the starter switch held on she will run, and run like normal. When I let go of the switch she stops, but the starter continues to turn over.
Looking at the electrical schematic, the Y/R wire goes from the switch to the starter relay, so I will trace the wire.
The starter switch also connects to the kill switch, which connects to the bank angle sensor and relay. I'm starting to wonder about that.
What and how to test and replace if needed? Are the parts even available, or are they needed.

Any and all advice is very appreciated. I'll continue to scour the past pages of this forum for now.

 

[dwalby]

how is your ability to read the schematic and trace things out? If you're any good at that, stop jumpering things and start tracing things out. If not, then ask a few more questions about things you don't understand.

Also, the comment earlier about the clutch switch wire not making any difference if its connected or not might indicate electrical modifications by a previous owner, hard to say. The clutch switch and sidestand switch provide the path to ground for the starter motor relay circuit, so they would both seem to make a difference.

Your reporting of what happens when you do various things doesn't seem to make sense based on the wiring diagram, so I can't give any advice based on that. You may have a modified electrical system, or you may have damage that's producing weird results.

 

[John OoSTerhuis]

This ST ran ‘intermittently’ when I retrieved it for Ken Robitaille (RIP) when he fell and broke his leg near me:

If you’ve removed the red 4P at the starter-relay/main-fuse unit and installed individual connectors, make sure the red wire is cut back to good, clean copper core stands, and the new female connector is on the correct spade.

John

 

[Smudgemo]

If you've got an issue going on like the one John illustrated, you may want to go a step further and I do the relay bypass mod outlined here: http://www.st-riders.net/index.php?topic=12377.0
I did my '96 early last year, and it has been perfect since. Fun project unless you hate electrical stuff.

 

[Schwangster]

Thanks John. My plug looked just like that.
I’ve cut back all 4 wires and replaced with new female spades. I’ll be doing the red wire bypass now that I’ve read what it is.

Currently I get zero voltage through the yellow/red wire when pushing the starter switch. As dwalby suggested, I’ve traced all the wires from the plug to switches. At this time I’ve gone back to work so it will be at least 3 weeks until next go at it.
My next checks will be the lean angle sensor and relay (which would cut the engine out), and a deeeper inspection of the main fuse box (as per another thread about electrical issues).
I have disconnected a couple add-ones that the previous owner had installed, but they were installed properly and have fuses. No issues found there.
We shall see.

 

[Schwangster]

After having checked and tested EVERYTHING, I finally found the problem today. I looked for the issue based on an old thread on this forum.
The ignition 10 amp fuse holder is broken, probably from corrosion.
I can jump the fuse with 12 v and she starts up and runs like new. But the fuse won't seat in the broken fuse holder guts. A small piece actually fell out when I pulled the fuse. Didn't notice a problem when I inspected this a month ago.

Anyone know where to get a new fuse box for the old girl, or am I going to have to adapt one?

Anyway, time to get her put back together and ready for next season!

 

[dwalby]

nice work,

I suspect you'll have an easier time buying an inline fuse holder and splicing around the broken fuse holder.

 

[Schwangster]

Good call. I had an inline fuse holder in my box of electrical stuff. Installed it and made it fit in behind the fuse box.
Works great!
I found a previously unidentified wire hooked into the bakc of the fuse box for an auxillery fuse box. I'll be redoing that connection as well.
May have had something to do with the broken fuse holder as it was hanging loose.

The adventure introduced me to the location of many items on the ST, including the bank angle sensor and relay, clutch switch, kick stand switch, and a variety of wiring connections that I had to learn about from the wiring diagram. Well worth knowing.

 

[GGely]

Best way to learn about the bike is to go exploring...

I have printed 11"x17" copies of the wiring diagrams for all the 1100's and laminated them with the heavy duty laminate. When I change something on the bike I mark up the drawing with a sharpie, then do a version on paper and laminate that. So I always have an up to date version of the bike, laminated to keep it clean. I have no idea why but my hands are always dirty around bikes...