Somethin's burnin....

Last week I came to a stop at a red light and noticed the smell of what I thought was some nearby grass fire...
Got home, into the garage, and thought, wow, smell followed me home...
Went to dismount the bike and discovered the smell originating from somewhere around / under the dash.

Checked the pipes, didn't pick up any trash / leaves / critters...

Next morning I fired up the bike and within 15-20 seconds I'm smelling smoke....

I don't see this mentioned as something the ST normally does...

I do know the original owner added 1 electrical mod: when applying the break, the brake lights and running lights flash a few times before going solid... (safety mod).


I'm wondering if there's a fire potential here... anyone else see this happen ?

I cooked a bird for a couple of days on the exhaust header, same kind of thing at stops and when parking at home I could not figure out the unpleasant oder. Also caught a few large butter flies and a Finch with the oil cooler on the RT. I have heard of people that had the misfortune of melting a plastic bag to their header pipes, bad smell plus real pain to clean.

Gerhard

bilturner said:

I don't see this mentioned as something the ST normally does...

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For good reason! It's not typical though it happens on occasion. The good thing is it's not the Magic Smoke that makes the ST so good.

Where there's smoke there can be fire. It could be any wire that's rubbed against the frame and worn off some of the insulation. Or a bad connection like a bad ground that causes an increase in resistance and heat. You might search hear for "bad ground" since that has been a problem with some older bikes. I'm not really familiar with that. Yet LOL.

It may or may not be related to the mod. Are these the factory brake and running lights that are flashing? Those are incandescents and draw a bit of juice compared to LEDs that are often added to the bike. A short in that wiring could draw enough juice to create some smoke. You might check if any of that wiring is under the dash.

You might pull some fuses to see if the smoking stops but that's a little shade tree and has some potential risk of real damage.

Definitely not normal. Like others have said, would be checking that out probably before I rode it again. Let us know what you find.

Dead frog on the collector pipes?? Don't ask how I know.......

Thanx guys. I guess I was thinking of trying it again on my commute tomorrow, but better to be cautious and fix it first....
Will start tearing into this weekend then...

Try to identify it by the smell. Plastic insulation from wiring is VERY distinctive - tho probably a lot like a plastic bag melting on the exhaust system. Birds or frogs will smell more like burning meat and feathers. You might turn on the ignition (maybe accessory only, first, for a few minutes) to see if the smell appears without the engine running. This would be a dead giveaway that it is electric in origin.

From what I have seen under the tupperware of my bike, Honda did a good job protecting and bundling the wiring harness. I would think, if it is electrical, that it was part of the po's modifications or a bad connector. If you want to discuss bad wiring harness/electrical parts, lets talk about old (60's) Triumphs and Lucas electrics.

I would think that the mod the PO did would be towards the back of the bike since it is for the brake lights unless maybe it is wired in under the dash near the brake lever switch? Makes sense to check that mod first since you don't know the quality of those connections. I don't think I'd chance riding it until the problem is found/fixed. Bike towing can be expensive!

Found no sign of smoke/burn/heat damage.

I did find 1 wire open / exposed near the connector. Odd. I was unable to trace it back to it's origination, so I capped it.

Burning smell is gone now. Reassembled, check-out ride, and all seems fine. Not really feeling that much better about it, tho. :/

That's not an oem wires so something someone may have routed to the dash for power to something. Glad you capped it. I would imagine it's tapped into something hot on the bike or straight to the battery. I don't like those kinda 'loose ends' and try to remove them to avoid future problems.

Mellow said:

That's not an oem wires so something someone may have routed to the dash for power to something. Glad you capped it. I would imagine it's tapped into something hot on the bike or straight to the battery. I don't like those kinda 'loose ends' and try to remove them to avoid future problems.

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...... but from the looks of it, no way it was causing a smell that you would notice on a running bike. My snoz isn't good at deciphering but it can tell the difference between something cooking on the pipes or radiator, and electrical smoke. Keep looking.

Taking a WAG but it looks like the PO removed a farkel (GPS?) and just cut the wire. I would check to see if it's hot with the key on and trace it back to where it get in to the OEM wiring. The connection method could be as workman like as the disconnect.

Len

TPadden said:

...... but from the looks of it, no way it was causing a smell that you would notice on a running bike.

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Agreed, that wire does not look like it has gotten hot enough to produce any smoke. Capping it off, while a good idea, probably is not the solution to the burning smell.

Take a peek at both headlamp connectors, especially the ground wires (Green conductor). The ground is the right-hand connection in this photo. I have had to replace both headlamp connectors due to overheated ground connections (Note: I use H4 60/55 watt bulbs), though I never smelled the insulation burning, they were indeed well charred.

As the charred insulation was only on the ground conductor, I felt confident that this was a localized incident due to resistance in the headlamp connector, and as such only required replacement of the headlamp connector, which included a short run of ground conductor.

SMSW said:

Try to identify it by the smell. Plastic insulation from wiring is VERY distinctive - tho probably a lot like a plastic bag melting on the exhaust system. Birds or frogs will smell more like burning meat and feathers. You might turn on the ignition (maybe accessory only, first, for a few minutes) to see if the smell appears without the engine running. This would be a dead giveaway that it is electric in origin.

From what I have seen under the tupperware of my bike, Honda did a good job protecting and bundling the wiring harness. I would think, if it is electrical, that it was part of the po's modifications or a bad connector. If you want to discuss bad wiring harness/electrical parts, lets talk about old (60's) Triumphs and Lucas electrics.

Click to expand...

I agree electrical is very distinctive as plastic burning. If it is to the point of smoking i would think it would blow a fuse by now. I went thru a grasshopper invasion and my bike smelled like chicken on the grill for a month!