Yamaha MT-03 ~ engine cuts out as soon as gear selected

[Toddot]

Hi,
I'm after some advice if possible.

I have a Yamaha MT-03 2007. I haven't riden it for circa 2 weeks. I went to start it today and it started and ran fine.
When I selected first gear the bike stalled.
The dash lights perform as normal - come on then all go out after a few seconds with just the neutral light remaining on when in neutral. When selecting 1st the bike just cuts out.

The sidestand is up, and I'm keeping the clutch lever depressed. As soon as I select 1st (down) or 2nd (up) straight from neutral the bike cuts out.

It won't start unless it's in neutral, so I think the neutral switch is ok. I put a continuity meter on the clutch switch and that is functioning properly.

I am wondering if the sidestand switch/circuit is playing up. I removed the switch but couldn't see anything obvious. I can't disconnect any wires to test it as they disappear off into a loom deep indise the bike frame. Looking at the manual it seems as though you have to remove the fuel tank to get to the wiring loom in the heart of the frame, but I wasn't too keen on doing that without getting some opinions.

Is anyone able to offer some advice? Does anyone have or had an MT-03 to offer advice on how to track the wiring loom for the sidestand switch. I'm wondering if a connector is playing up in the circuit or the switch itself if playing up.



Thanks in advance

[Nobby the Bastard]

Its the side stand switch.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[Toddot]

Hello Nobby,

Thank you for your reply. I can't get to the end of the side-stand switch cables (or any connectors that may be inline with the cabling, I think they are under the fuel tank).

Is this a common problem?

Do you know if the 2 wires need to be shorted together to allow it to work, or open circuit?

If I cut the wires as it comes out of the switch I can leave them either cut (open circuit) or twist them together (short circuit).

Before I do this, is there any way it could be anything to do with clutch plates (not that I have messed around with the clutch at all, and it was fine when I last rode it a couple of weeks ago)?

Thanks

[Nobby the Bastard]

It will be nothing to do with the clutch plates.

I have no idea whether it's open circuit or closed circuit to convince the stand is up. If you a brave, cut the wires and see if it works. If it doesn't twist the wires together and see if it works.

If twisted works, ffs do a better job of connecting it bbefore you start ridiing the bike again.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[Easy-X]

Most bikes for wiring on that side it's a bit more obvious where the cables run if you unbolt the front sprocket cover then see if you can follow the cable and find a connector.
____________________
Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[Toddot]

Hello Easy-X

Thanks for the reply.

Trust me, I did remove the sprocket cover. The two wires go into a large pack of cables covered in a plastic/rubber shroud deep inside the frame where I can't get my hand. I didn't want to pull the whole loom too much, as I might end up causing a problem with other wires.

I will report back this evening

[Easy-X]

Fair enough, I was hoping it was like the oxygen sensor the other side.
____________________
Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[WD Forte]

Those Yammie side stand switches are damned expensive
best part of a oner new from foulups but have to be ordered from Japan
Here's a cheaper one from France, brand new but half the usual price
part number 5VS-82566-61 btw

https://www.ebay.co.uk/itm/401402926388?

https://www.fowlersparts.co.uk/parts/5432770/mt03-2007-5yk4-europe-25kw-light-bluish-gray-metallish-5/electrical-2
____________________
bikers smell of wee

[Easy-X]

There are other Yamaha side stand switches that look very similar. A knock-off MT07 switch (which is most likely the same) £20~£25.

<edit> the main difference between the parts seems to be cable length. If you're chopping the cable maybe factor in eventually fitting a socket to the end so you can use the cheaper MT07 part.
____________________
Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[Toddot]

Thank you Nobby, you were spot on.

I took the side-stand switch off which revealed a top metal plate on a plastic switch body. I removed the 4 screws holding the plate on, half expecting the inner parts of the switch to go shooting off in all directions, but they didn't. The top plate has an inner insulator with the two contact points on it connected to the two cables. The plunger has a copper bar on it under slight tension via a spring underneath it, which keeps the copper bar pressed against the top insulator and the two contact points with the side-stand in the up position.

Shorting out the two contact points allowed the bike to go into gear when running, so definitely the side-stand switch.

It was a bit oily inside and the contact points had dirt on them and probably a thin layer of oil, although difficult to see that. A thorough clean out, screwed back together and re-fixed into position and it's all good.

I'm hoping it was just dirty contacts and the ingress of oil and not an impending failing switch - time will tell.

So thanks for the pointer Nobby, much appreciated. Thank you too to Easy-X and WD-Forte. I'll bear the switch links in mind if the switch does fail WD-Forte. From what I've seen inside the switch now, it is astounding how much they can charge for it!!

So, if anyone has the same issue, don't be concerned about removing the switch cover plate. Just keep the switch flat and nothing should fall out, and just give it a clean, you have nothing to lose.

On a final note - good forum. No scarcy comments from those that have probably seen this issue countless times , I am a fairly new rider of circa 3 years so learning as I go. And reliable advice.

I did post in another 2 forums, well 1 I tried to but it wouldn't actually let me post, and the other has had no replies.

So thank you, I'll definitely come here again.

If anyone wants MT-03, XT660X/R or XT660Z wiring diagrams I can photograph them.

Toddot

[Nobby the Bastard]

You didn't say anything worthy of ridicule so you didn't get abuse. Don't assume this will be the case with every interaction with me...
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[that_impulse_guy]

sidestand switches...clutch switches...all mandated by EU "euro xxx" regulations which are pretending to be about emissions control.
I mean how the f*** am I meant to start my bike to warm it up while I have a smoke on the sidestand if a little switch says no?

Also, millions of us didnt drive off with the sidestand down, and those that did,only did it once. Ive got a cool spectacles testicles wallet watch routine I go through before setting off, including "sidestand ya bastard" which ensures I pay attention.
____________________
Gone: Yamaha DT50lc, Suzuki DR500, Suzuki A100, Kawasaki z250ltd, RD350YPVS, Suzuki DR Big, Kawasaki AR125, Kawasaki KMX200, Suzuki GS1000S, Katana 1100, GS550M, Suzuki RGV250
Now: Suzuki GSX400X, Suzuki RF900R, NS400R

[Nobby the Bastard]

Btching about nothing again. They are nothing about emission controls, they are about stopping you from riding away with the stand down.

Yes, I know they are a pain when they fuck up and are not really necessary but why bitch about them being somethinng they are not?

Twat.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[A100man]

[Nobby the Bastard]

Fuck off and die.

With cuddles.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[Ayrton]

[jeffyjeff]

[Evil Hans]

[Toddot]

Hello again all,

I have an update on this issue, and hopefully some more information, which i am hoping someone could further advise.

Currently the bike has the sidestand switch shorted out; this is because what I thought had fixed the problem it would seem hasn't.

I checked against what the manual says regarding operation of Neutral switch, which appears to be working as it should (dash lights do what they are supposed to do at power on, a few seconds after power on when self check is complete and when the bike is running and going through gears). Therefore Neutral switch currently still in circuit.

I have now disconnected the Clutch switch. I did this because I broke down approx 300m from work. Managed to get to work and a more experienced rider had a look and thought it could be this. Disconnecting the switch wiring allowed the bike to start, go in gear and ride around. Great I thought. This was further tested by shorting out the wiring with a link and the bike cut-out. Putting the wiring back on the switch had the bike cutting out just by poodling around the car park and changing gear (once I had managed to get it to stay running when first was selected). Disconnecting again had the bike running fine. I managed to ride home with no issues with the Clutch switch disconnected. I removed the switch and tested it with a multimeter and couldn't get it to fault, not even intermittantly. I opened it up, gave it a clean, put it back together, retested on multimeter and still couldn't get it to fail. Still left it disconnected.

Over the next few evenings I went for a local ride just around town (Clutch switch still disconnected) to see if it would fail again. It didn't. Great I thought, I'll leave both the sidestand switch shorted out and the Clutch switch disconnected for a week or 2 just to prove the bike was now fault free.

Today (Saturday) I went out for a 30 mile ride. The bike cut out whilst riding. I would pull over, start the bike - fine, put it in gear and it would die. I broke down three times in all. Each time it took random tries to get it running again. It might go into gear and run after 2/3/4 attempts, another time it may take 10-15 attempts. But each time I was heading back home just to get back home to start with, which I managed. When it was running, it was running fine.

So, it would appear this is a completely intermittant issue. It was just the case that each time I thought I found the issue, it was actually only temporarily running until it decided to fault again, which might be for 5 minutes or might be several days.

I will add that I've only riden the bike really to test since this has been going on, so not regularly riding each day.

So:-
1) Bike will start as it should (all dash lights indicating normally).
2) Goes into gear and rides fine UNTIL it decides it will start but cut-out as soon as a gear is selected, or
3) Will cut out whilst riding (no indication of a fault, just dies), and will then (to date anyway) revert to (2) which can take any number of random attempts to get it going again.

To say I'm nervous riding it now is an understatement, because I simply don't know if it will die at any minute.

When the ignition is turned you can hear the fuel pump whirring for circa 5 seconds and then stop. The bike will then start. I haven't got to the stage yet where it's failed again and I can check to see if the fuel pump is not whirring in this failed state.

The bike has a kill switch, which I haven't investigated yet, but may do next time the fault reappears.

It has an immobiliser; I have done nothing regarding this yet.

One thing that did happen today whilst I was out breaking down at random stages, is when the bike had started and was running in Neutral, I revved the engine quite hard to see if it was fuel related and possibly flush something through. It would rev up fine as it should. But other times when I started it and it was running in Neutral, I only had to touch the accelerator very slightly and it spluttered a bit (almost like on the edge of dieing for a second and then died). This could be totally unrelated and purley co-incidental but I thought I'd mention it incase it's relevant. I'm a bit unsure of this and almost want it to fail again to see if this is something that will happen again, or just whether the bike was getting pi$$ed off with me trying to continually get it to run.

So, has anyone got any pointers please?
Also, do bikes (this one) have anything akin to an ODBII port where a diagnostic scanner can be plugged in to interogate logged faults or past history?

As you can no doubt tell, I'm learning here as I go. Depending on what happens next faultwise, I may be looking to remove the fuel tank to check electrics under here, where the battery, fusebox, main relay, ECU, etc is supposed to reside. I have to say I don't fancy removing the fuel tank, and am frankly somewhat dismayed that all this is under the fuel tank, resulting in the fuel tank having to be removed to check something electrical out and further more having to put it back to test if what may have been found has worked, to then remove it again, etc in a constant loop. Doesn't seem the best design to me.

Thoughts/ideas welcome, as I'm running out of ideas.

Thanks in advance and apologies for the long post, just wanted to put as much info as possible.

Tod

[Easy-X]

There's some wire joint or connector that's failing. Static, it's holding together but out on the road and jiggling about is probably the trouble.

The wiring diagram, a multimeter and some patience is what you'll need. Identify the neutral, side stand, clutch switch circuits (kill switch too) and work out how they all relate to the ignition system. Then it's a case of following the wires around and jiggling things until you can consistently reproduce the fault.
____________________
Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[Toddot]

Hello Easy-X,

Thanks for the reply. Your advice makes perfect sense, and to be honest something that I thought but apprehensive about attempting to remove the fuek tank, which needs to be done to trace cables to ECU, Starter Relay, etc, as they are all under the tank.

I'll come back with further info once I start stripping down, but it may be a fews days.

Tod

[Toddot]

Hello all,

Update on this issue, which I've purposely left a while before posting.

Having had this random issue and looking at different components with only brief succes until the fault came back again, I decided to go all in.

Seats off, tank off (figured out the fuel pipe clip) and exposed the ECU, starter relay and main frame of the bike. Found a main loom going across the top of the bike from instrument cluster to the rear where the ECU is. In roughly the middle of this loom another large loom drops down to the sidestand switch/regulator area.

On this lower loom connects the clutch switch, sidestand switch, regulator, amongst other items. I decided to disconnect all of this and pull the whole loom out (which was a git), the plugs on the end made the loom diameter considerably larger to get through the narrow channel.

Once out, I found the loom wrapped up in gaffer tape!! Unwrapping this exposed circa 15 cables, 11 of which were either crimped together with scotch connectors (new piece of cable crimped into the cable where the original cable had failed) or the original cable badly burnt/melted and wrapped up in insulation tape.

In short, nearly all of this lower loom was fukced. 4hrs of cutting out each damaged or crimped section of cable and replacing it, soldering onto the existing good part of the cable, rubber sleeving, heat-shink sleeving and then wrapping up the whole loom back into one.

Then pulling the loom back in place through the narrow channel with the plugs on the end (even worse than pulling it out).

All back together.

The bike has done circa 150 miles since and has not played up so far. In fact, it is noticably better at starting (quicker and cleaner, almost instant). I surmise the damaged cables with higher resistance were enough to make the various circuits, but causing poor perfomance for electrical conductivity. Whoever had it previously did a full-on bodge job of repairing a burn-out event. Don't know if it previously had an electrical burn out or the loom came into contact with the exhaust pipe which runs in the same central area.

The exhaust pipe is wrapped up in some form of lagging. Is this how the bike was from new or should there be some form of heat shield? The Haynes manual doesn't descibe any heatshield in removal and refitting of the exhaust so I'm surmising not.

The moral of this is, if you're like me and not particularly mechanically minded, but faced with a problem that a garage would undoubtedly charge an arm and a leg to trace and fix, then give it a go, taking photo's of everything as you go. I am an engineer, but electrical, so disassembly is not alien to me, but I'm certainly no mechanic.

Tod

[recman]

Well done with finding and repairing the fault.
Also, congratulations on your tenacity.
It was an interesting little thread.

[Easy-X]

[Toddot]

Thanks recman, I just wanted to let anyone know who may have the same issue.

@ Easy-x, yes. it wasn't great! What gets me is I've been riding it with that issue for 3 years. It could have failed at any time (which is obvious), but when I think of all the places I've been when it could have failed.

Oh well, I learnt a bit more about my bike.

Toddot