Travis

[Travis]

Hi guys, i own a yamaha mt 125 14 plate and last week it died on me and couldnt understand why after getting the bike home and trying to find and fix the problem after constantly being on google trying to find if someone has had the same problem i still dont know what could be causing my problem.

when i turn on the ignition my dashboard doesnt light up however all my fuses are fine and my indicators, flash and plate light all still work.  I can even get the bike to start cranking over but it wont fully turn over so ive been unable to ride since the breakdown.

does anyone have any ideas or suggestions as i need the bike back on the road asap for commuting to and from work.

 

ive tried finding a lose or damaged connection but i dont know enough about the bike to confidently take alot of the parts off to get to all the wiring.

any help would be greatly appreciated 

[dynax]

It could be a knackered battery

[Discomfort]

Second this, battery. Do you have a multimeter to measure the battery voltage at rest and while cranking?

[husoi]

If the bike was running and not charging the battery, you could be facing an alternator or controller problem.

As above, test the battery, if you can get hold of a car battery try using it to start the bike and check if it is charging the battery.

The only reason why a battery would go flat is if left plugged for a long period and parasite currents drains it down. A battery on a bike that is used frequently shouldn't go flat so that is a sign that your problem is not the battery.

[Travis]

2 hours ago, Discomfort said:

Second this, battery. Do you have a multimeter to measure the battery voltage at rest and while cranking?

Measured the voltage across the battery and with ignition off it read 12v with the ignition on it read 12v however when it cranked over it read just under 5v.

any ideas?

[onesea]

An easy test for you..

If you have another battery try it with jump leads to other battery..

If other battery is in vehicle do not leave that vehicle running.

If bike starts normally and runs ok on jump leads, it's probably the battery.
If same problem exists its probably not the battery.

Edited November 21, 2020 by onesea
To make the advice more correct....

[Fish]

Could be the kickstand switch. By all accounts it's a known issue on the MT125's.

 

Fish

[Bender]

The fact it's dropping to such a low voltage points to battery 

[Travis]

Everything electrical works apart from my dashboard it doesnt light up at all if nothing worked i would understand that the problem would probably be the battery but because everything else works and its just the dashboard that wouldnt turn in when the ignition is turned on i dont think it is the battery 

[Bender]

12v is not a good reading for a standing battery anything below 12.4 volts is pointing to a battery that's sulphated.

 

5v is either battery that's not getting a charge and is in need of it, there is a complete dead short, smoke and possibly flames would give that away, or the battery is dead and can't take a charge.

 

You need to work out which one it is.

[Mississippi Bullfrog]

5 hours ago, Travis said:

Everything electrical works apart from my dashboard it doesnt light up at all if nothing worked i would understand that the problem would probably be the battery but because everything else works and its just the dashboard that wouldnt turn in when the ignition is turned on i dont think it is the battery 

The dashboard probably needs a certain voltage to activate. Low battery charge can cause all sorts of weird issues with electronics.

[WD-40]

The battery is flat. Give it a charge and see if the bike starts. If it's still struggling to start after it's been charged it needs to be replaced. It probably needs to be replaced if it's dropping to 5V. Cold weather kills weak batteries. 

You could try push starting it. Turn it on, pull the clutch in, put it in 2nd gear, push it as fast as you can and release the clutch. The bike should start. Pull the clutch in straight away or it'll ride off without you.

[Travis]

Got a new battery and it is fully charged, changed all the fuses in the fuse box and also bought a new display just incase it was my display but nothing has changed. Anyone know what else i could check ?

[Six30]

are there any wires getting pinched squashed  when you turn handle bars ?

[Travis]

9 minutes ago, Six30 said:

are there any wires getting pinched squashed  when you turn handle bars ?

No all the wires are protected and havent been moved

[Mississippi Bullfrog]

At the back of my mind is something to do with the ignition switch. A bad connection in there could cause this kind of issue. You might need to do some searching with a multimeter. Don't assume that 12v present means there's sufficient current flowing though. I've had corrosion within cables cause similar issues despite a healthy voltage showing.

[fastbob]

Sounds like a bad connection somewhere . You're going to have to pull apart all the multi pin connectors and get in there with little folded up bits of sandpaper or a needle file set and clean everything up . And don't be misled into squirting WD40 over everything because all that will do is make it smell nice . Start with the one that connects the dash board ( Obviously ) Good luck . 

[caveman]

16 hours ago, fastbob said:

Sounds like a bad connection somewhere . You're going to have to pull apart all the multi pin connectors and get in there with little folded up bits of sandpaper or a needle file set and clean everything up . And don't be misled into squirting WD40 over everything because all that will do is make it smell nice . Start with the one that connects the dash board ( Obviously ) Good luck . 

definitely sounds like some sort of crappy connector or water ingress somewhere.

As Fastbob said don't use WD40, I see so many people squirt that stuff down ignition barrels and into electrical connectors, it's shocking. Get a tin of dedicated contact cleaner and give the connectors a squirt, unplug them and reconnect them a couple of times. I have fixed many a niggly fault this way and always have a tin on hand. As well as fuses it may be worth checking any relays in the ignition circuit as well.

 

 

[WD-40]

You could check the connections on the starter relay. The bolted ones. Make sure they're tight.

In your first post you said "I can even get the bike to start cranking over but it wont fully turn over". What did you mean by it wont fully turn over? I understood it to mean that the starter motor was turning slower than normal. Is that what you meant? Has putting the good battery in changed that or is it still doing the same thing as before?