Gt550 electrical problem from killswitch to coil

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hectus
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Joined: Fri Apr 17, 2020 12:27 am

Gt550 electrical problem from killswitch to coil

Post by hectus »

Hi folks

I had the engine in and out of my 75 gt550 and for some reason or another, when i turn ignition on and set the killswitch on run, the orange wire with white stripe, that runs from killswitch to coils, starts smoking. I have checked the wire itself and followed it down to the coils, i cant find any fault with the wire, but when measuring on coil end, the orange w yellow wire is grounded on/in the coils.

This wire should have power with the killswitch on as far as i understand, so why would the coils act like a earth point? i must be missing something, or possibly something i havent hooked up that im supposed to.

Bike was fully running before i pulled engine out, coils and rest of the electric also fine, so i think im overlooking something somewhere.

Anyone have any suggestions on whats going wrong here?

Thanks for answers and suggestions
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canaletto5
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Location: Derbyshire

Re: Gt550 electrical problem from killswitch to coil

Post by canaletto5 »

Have you unplugged the coils and then measured the resistance between the kill switch orange/white wire and earth?
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Alan H
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Location: Wombwell, Republic of South Yorkshire

Re: Gt550 electrical problem from killswitch to coil

Post by Alan H »

The orange wire from the kill switch is earthed somewhere.
Proof that four strokes are over complicated
hectus
Posts: 4
Joined: Fri Apr 17, 2020 12:27 am

Re: Gt550 electrical problem from killswitch to coil

Post by hectus »

Thanks for your answers.

I havent had much time to troubleshoot until yesterday, after a lot of tracing i found out the orange with white stripe wire actually goes all the way back to the voltage regulator, and the problem wire was actually one coming from the stator that had rubbed thru right after the stator cover.

Well, got this sorted, now im having a problem with the starter. Very frustrating, the wiring is all fine, the starter will crank but its very weak, i measured a massive draw of 30 amps even when starter is out of the engine and when ohm'ing it shows to have a short, get ground connection even on the positive screw on the starter. Brushes and everything inside the starter seems fine, nothing obvious wrong that i can tell.

Changing brushes and such is what i can do, but i have no knowlegde on how to start messing around with the windings or simular, so i guess i will try get a hold of another starter.

Is there any known/common fault with these starters?

Do they fit from other bikes? like the gt750 for example?

Any suggestions on where to get a decent used starter? it didnt look like its much to chose from on the "bay".
barney01
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Joined: Wed Sep 26, 2012 7:33 pm
Location: Prestatyn.Wales

Re: Gt550 electrical problem from killswitch to coil

Post by barney01 »

Send Baz on here a PM he can get the starter repaired or sell you a new one
NO SMOKE .......NO POKE
asco58
Posts: 122
Joined: Sat Nov 21, 2020 2:24 am
Location: London

Re: Gt550 electrical problem from killswitch to coil

Post by asco58 »

In some cases, if the bearing/bushing surfaces that hold the armature in place wear out, the armature can come into contact with the casing and magnets which shorts the positive terminal to ground. The tolerances are quite slim. I've had this before on a different bike. Also the GT750 starter motor doesn't fit the GT550. If the motor's not obliterated then it could probably be repaired. As Barney says, probably best to contact Baz about it.
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Alan H
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Location: Wombwell, Republic of South Yorkshire

Re: Gt550 electrical problem from killswitch to coil

Post by Alan H »

550 starters are unique to the 550 and if they're ok, they work.
If you do an intro and let us know which bit of the world you inhabit plus a bit of your biking expertise details, we might be able to suggest a 'local' place of assistance.....
Proof that four strokes are over complicated
asco58
Posts: 122
Joined: Sat Nov 21, 2020 2:24 am
Location: London

Re: Gt550 electrical problem from killswitch to coil

Post by asco58 »

A GT550 starter motor came up on eBay:

https://www.ebay.co.uk/itm/SUZUKI-GT550 ... SwNJRgTKoe
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