Starter trouble on GN250

[Brown Bear]

Broke down today on the Hobsonville highway.If you were the motorcyclist who stopped to help thankyou very much.Two people in a van stopped not long after loaded my bike into there van and gave me a ride home,Thank goodness there are still some good people around. My problem ,even with the key turned of ,and kill switch on when i put a new fuse into the holder by the battery ,the old one had blown, the bike turns over and tries to start before blowing the fuse.Is this a computer trouble if it has one so i will have to put it in the shop,or something a bit more minor.Where do i start to try and find the fault.Any help appreciated.

[Guided_monkey]

How big is the fuse?

Without any wiring diagrams I would suspect that you have a short cct in your starter feed line. You state the bike cranks and then the fuse blows.

Get a multimeter and test the line leading from the starter relay to the frame.

If there is low resistance, then more than likely the starter motor has developed a fault.

PM me if you need a hand. :yes:

[notme]

Google for a service manual or at least the wiring diagram part of it for your model/year. A few secs on google got me the attached, but it's only a generic system diagram, and it may not be your specific model year. The full diagram will give you wire colours etc and make this a lot easier....
232600

Anyhoo, if the starter is cranking the engine it's because it's getting current. If it's getting current, either the starter relay is stuck on, or it is being told to come on.

Look at the diagram - for normal operation the starter button, engine kill switch, and ignition switch all need to be ON for the starter to be engaged. If your kill switch and ignition are off and the starter is running, it can't be because the starter button or it's associated wiring is damaged, it must be the wiring around the starter relay or the relay itself.

What you want to do is remove the feed from the starter relay and see if the starter still cranks over (meaning the relay is stuck closed). If it doesn't crank over, the relay is OK but the feed to it is stuck on, and you should look for a problem in the wire marked by the arrow. It's more likely that the relay contacts are stuck on than that the feed is stuck on, so hopefully you just need a new relay.

However, it's worrying that the fuse blows, because that means current is going somewhere it shouldn't - maybe it's all to do with the relay, or maybe it's a root cause.

When the bike cranks over, does it sucessfully start? I'd guess no....

[BASS-TREBLE]

GNs only have one fuse but the wiring is rather basic.

I would try push starting it and when it fires see if it'll blow the fuse, which I assume it will since your broke down originally due to a blow fuse.

My guess is that you have a short/stripped wire somewhere, possibly nothing to do with the starter. When you crank it the vibrations make that shorted wire move which probably comes in contact with the frame or some other ground.

If the blown fuse had something to do with the starter it would blow as soon as you hit the starter, not even leaving enough time for the starter to start spinning.

I would take the seat of and look for any wear marks on the wires as this would be where it is most likely to take the insulation of the wire and cause a short.
Possibly also remove the frame and look for any sharp edges that the wires pass by/are close to and inspect carefully.

It would pay to also check inside the headlight as there is a spaghetti fest of wires in there and it is possible there is a false ground there somewhere.

Let us know how you get on

[Brown Bear]

Hi Allun
Thanks for replying.You are right, when the bike turns over it does not start.Do i need to remove the starter.
cheers Matt

[notme]

I would try push starting it and when it fires see if it'll blow the fuse, which I assume it will since your broke down originally due to a blow fuse.



If the blown fuse had something to do with the starter it would blow as soon as you hit the starter, not even leaving enough time for the starter to start spinning.

He's saying that as soon as the fuse is put in the fuse holder the starter turns over - so there's no way to try crash starting. It's definitly something to do with the starter circuit :yes:

[notme]

Hi Allun
Thanks for replying.You are right, when the bike turns over it does not start.Do i need to remove the starter.
cheers Matt

Cool. So I think we are getting somewhere, the fault is in the starting circuit -proven by the fact that the engine stop switch and ignition circuits are behaving as they should (by not letting the bike start).

So now try the test I previously suggested -




What you want to do is remove the feed from the starter relay and see if the starter still cranks over (meaning the relay is stuck closed). If it doesn't crank over, the relay is OK but the feed to it is stuck on, and you should look for a problem in the wire marked by the arrow. It's more likely that the relay contacts are stuck on than that the feed is stuck on, so hopefully you just need a new relay.


Another quick google gave me this pic
http://www.wemoto.com/bikes/Suzuki/GN_250_F_J_M/87-92/picture/Starter_Solenoid/
you should have a starter solenoid that looks like this, probably mounted right on the starter or else very close. Unplug the wire coming from it and see if the starter still turns when you pop a fuse in. I hope you have a few spare fuses :-)

[notme]

Actually going by BASS_TREBLES's sig, he might be able to point you to where the starter solenoid is located..........dude?

[Brown Bear]

Thanks Allun
The starter soleniod is under the seat.I noticed it there when i removed the seat last night.By the wire coming from it do you mean the wire between the starter and the soleniod.
cheers Matt.Looks like Bass Treble might be the man to get parts from.

[notme]

The thin wire is the one to remove - in the photo i linked to it looks greenish or yellow, it might be a different colour on yours but it will be the thinnest wire by far.

THe way the solenoid works is that the thin wire carries a small signal that tells the solenoid to pull in and send high current to the starter. By disconnecting that wire we will know if the problem is the solenoid being stuck on when it shouldn't be, or if it is just doing what it is told and the problem is with the signal wire. I suspect it's stuck on.

[Brown Bear]

Thanks for that.I know the one you mean.I finish work at one so i will head home and try it.Lets hope all i need is a new soleniod.

Cheers Matt.I will let you know how i get on.

[Brown Bear]

If it is the starter soleniod,do you have to buy them at a bike shop or can you get them at supercheap or repco.

[Brown Bear]

Disconnected the thin wire as you said. Didn't try to start,so soloeniod stuck close.Where to buy new one.

[BASS-TREBLE]

Oh sorry guys, I got the wrong idea from the first post.

Yeah solenoid is under the seat like you said. I don't have a spare one sorry.

Being this time of the day youre a bit out of luck but on monday you could try a local bike shop. It is a GN so it will have a rather small current rating, does anyone know the rating on here? They may have some used ones lying around, most other bike ones should work anyway.

Either way, take of the old one (DISCONNECT BATTERY FIRST) and take it with you to make sure you get one with the same size connectors and the rest should be easy.

Unless it is a GN it probably wont bolt to the bike like the original but just secure it somehow. Even one bolt should be enough.

[Brown Bear]

Thankyou Bass Treble looks like bike shop Monday.

[BASS-TREBLE]

You can get them from Repco etc but that would be a last resort for me since a bike shop will probably have one lying under a bench in the workshop and would probably give it to you for a hell of a lot cheaper.

Also if you know of a bike wrecker then that can be worth a shot too.

[notme]

Hang on a sec guys.....

Don't get a new solenoid yet!


Disconnected the thin wire as you said. Didn't try to start,so soloeniod stuck close.Where to buy new one.

If it doesn't start when the soleoid drive wire is disconnected, then the soleoid is not stuck. The problem is the the drive wire is being given a signal, telling the soleoid to engage and turn the starter.

So, start looking at the solenoid drive wire, trace it back to where it goes (which will eventually be the starter button on your handlebars) and see what you can find.

[Brown Bear]

Thanks you all,but a big thankyou to Guided Monkey for coming around with your multimeter and finding the problem.It was some of the wires behind the headlight melted plus one plug.Can be fixed so i am after the bulb holder back to the first plug,these wires and plug are screwed.I just want you to know that this GN owner apprecitated people taking there time to try and help me out.

Cheers Matt

[notme]

Some of us enjoy the challenge mate :-)

Nicely done monkey - hope you got a beer for your efforts!

And in case it helps future searchers who may find this thread, one of the wires behind the headlight that was giving Matt problems will be the starter signal wire, and something in the melted wires was causing the short which was blowing the fuse. Seems that headlight wiring area is an issue on the gn's :-)