member1351

Update:

The issue has now been fixed!

Replaced the ECU unit with a pre-owned one (ordered from eBay) and the tachometer is now working again.

new pump under £30, https://www.wemoto.com/bikes/yamaha/ybr_125_custom/10/picture/fuel_pump

Excellent! You are a star mate.

In the meantime, I called my local dealer (their workshop), the engineer said this is a known issue for YBR 250 and there had been recalls but didn't think YBR 125 had the same issue. He suggested contacting the HQ (via email) as they might offer sth!! I will give that a try too!

It could be the fuel pump, if it's getting hot enough for it to seize up, it might be worth stripping it down and giving it a service

The battery trial didn't solve it as expected. The bike is back in shade!

OK, that will be the next job. I wonder if it is worth swapping it out to an aftermarket Fuel Pump while stripping it!

One good thing that came out of the current national restrictions for me ... is playing with this toy and testing all these things. I was probably going to get stuck on a country lane waiting for a recovery truck, had this been an ordinary day!

is it a carb or fuel injection model ? can you disconnect the fuel line from the petcock if it has one and see if any pressure is released.

It is a fuel injection model. I can't see any petcock.

Interestingly, I thought of doing another test. It was all working fine and firing up in my garage all morning.

Took it out to the garden & put it under the sun for an hour or so. Now it won't start, it is not particularly a warm day but it is sunny here in Berkshire (the tank got warm under the sun). The fuel pump doesn't make any noise whatsoever when the ignition is ON! Nothing!

I have not moved it back in the garage yet, so I could investigate a bit further.

I have just disconnected the battery to see that will reset the Fuel Pump by any chance (long shut but I thought worth a try).

If it's vapour lock (Fuel Injection was supposed to help stop that) try opening your Petrol cap, turn on ignition ,dont start the engine (or try to) and let the pump run, do this at least 5 times , it might help to force any gas out of the line.

But when the issue arises, the pump doesn't do anything. No noise, no movement.

It however it becomes alive after the cool down period!

It sounds like vapour lock to me

 

Do you think there might be a simple cure for it?

Thanks - will check them out.

It sounds like vapour lock to me

Do you think there might be a simple cure for it?

Trust me, I could not believe it myself.

And I check everything on it when it happens:

- Battery New

- Starter fine

- Kick start won't help either

- The starter tries and tries - but nothing

- All the wiring intact and spot on

- Center stand / side stand switch all working as they should

- Tank full

- Spark plug new

- When tank temp goes down - it starts first attempt

Please Google the model/issue - see how many owners experienced the same thing.

First time happened to me I ran every single test on it not knowing that the heat might have been the issue!

Hello mate,

Yes, I have.

The only way to get it back up and running is either a long standing in shade or a bucket of cold water on tank!!

I have read that some other owners also used wet towel to cover the tank.

Hello,

My YBR Custom 125 (2010) won't start whenever left under the direct sun - when moved to shade and tank cooled down, it will start straightaway ... Googled the issue, it seems to be a common issue with Fuel pump.

I wonder if any of you YBR 125 owners experienced the same issue?

Anyone used an aftermarket fuel pump to rectify this issue?

What brand & how much roughly?

I am keen to not replace mine with anther pump that may fail for the same reason.

Many thanks in advance.

Hi ThePhatomfart,

I tested the CKP as well. Looks intact and return the recommended resistance result as per Haynes manual.

I also re-tested the continuity from Tach to ECU - absolutely fine. So must be the ECU!

Unless someone else out here might have a different view!

Thanks for this.

Very interesting. The Tach doesn't even want to move when in Idle. It only moves when it is rev'd up.

One thing I certainly need is a reference as to what the RPM readings should be for this bike.

For example in normal riding condition what should be the reading in 1st, 2nd, 3rd ... gears.

I feel that the RPM readings I am getting when I wire it directly to the Ignition Coil are far too low.

At around 30mph, it is hardly reaching 2500rpm while I can hear the engine high in REV. That doesn't sound right to me!

Yes, I am thinking ECU as well - some cheaper ones can be found on eBay around £30ish. I am tempted.

Not sure if there is anyone around me in Berkshire that I can borrow the ECU unit from - especially with the current chaos!

I will test the CKP as well. It didn't occur to me that CKP could also play a part here!

Hi , dont know this bike , but would ave thought 20+volts coming from the ECU to the clocks seem a lot, the pulse for the Tach would come from somewhere like the CKP to produce that pulse to the ECU, as the bike is running the CKP must be working OK, but maybe just a clean of it may work

Hello mate,

I will have a look at the CPK.

Since my last post, I hardwired the Tach directly onto the Ignition Coil and bang the Tach started working. However I don't believe the RPM readings are accurate or even realistic when feeding directly from the Ignition Coil.

Maybe it should feed it directly from CPK?

Could the ECU unit be at fault here?

I suppose the readings go to ECU and that is where it gets put into a correct range!?

Can the Rectifier be at fault here?

Thanks.

Hello,

I was hoping that someone out there could help, please?

Yamaha YBR 125 owners?

Anyone experienced a similar issue?

Thank you.

Hi All,

I am new to this forum and sorry for starting with a technical question as my first post!

My bike: Yamaha YBR 125 Custom 2010

I bought the bike a couple of weeks ago and loving it. It rides and look great. And work as it should apart from its tachometer not working at all. The previous owner stated that it stopped working halfway through a journey for him a while back and he never bothered looking into it.

II am trying to fix it, so opened the instrument cluster and checked everything, all the wiring look fine and I get a reading of 26.7v AC (increases to 27v AC when I rev it up) on the Blue/Yellow wire (which I believe comes straight from the ECU) and then 12v DC on the Brown cable. The Ground seems to be fine too.

I thought that it might be the tachometer unit itself so I ordered a second hand one from eBay (came from a 2013 model). But no luck when connected the replacement unit too.

I am really puzzled - the likelihood of the replacement tachometer being faulty must be very very low. So what can the issue be?

The battery seems to be new.

The battery connections are solid and spotless like new.

The bike runs and sounds as it should.

Can anyone help please?

Any idea?

Really appreciate your help.

Many thanks.