Yamaha YBR 125 - Hot day starting problem

[simonjb]

Hi, I'm very aware of the problem a lot of YBR 125 owners suffer with starting the bike after leaving it in sunlight, or on a hot day. The fuel pump does not run at all until the tank has cooled - and there's been a lot of speculation as to whether it is the heat or fuel vaporisation.

I'm currently waiting for the tank to cool down with a wet towel as I've heard this works, but I'm looking for a longer term solution. Should I get a replacement fuel pump, or would the new one be at equal risk to this problem? And if I do get a replacement, would a 2009 onward inner tank pump fit to my 2008 model? As these are the only ones I can find available on ebay, as I can't exactly cough up the cost of a new one.

If anyone has found any other long term solutions, other than "don't park in the sun", please let me know! Thanks

[Dave M]

[Dave M]

On a more serious note. Was there a call back on these bikes as well as the yzf r125's on fuel pump? My 2008 r125 had a call back for the fuel pump and I THINK it was the same for the ybr125. Anyone please correct me if I'm wrong. Give your local dealer a ring to see if there was a call back. Hope this helps pal.

[simonjb]

I wasn't aware of one, as my bike is a second hand one I bought from a classifid ad about a month and half ago. But I'll give call of the dealers and try to find out, if there is then I might be able to get it replaced for free, or at least with minimum labour charges.

[Nemo]

Check this - https://www.vosa.gov.uk/vosa/apps/recalls/

It doesn't matter whether or not it's second hand, if there's a recall they will still do it.

If it's a recall there is also no charge, if there isn't a recall don't take it to a dealer, buy an OEM part and do it yourself, it can't be that difficult since I don't think it sits in the tank, could be wrong though.

If you're not mechanically handy then take it to a reputable local garage, the labour charges would be half the price and they'd do exactly the same job to the same standard.
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Previously owned: Kawasaki KH125, Suzuki GP125, Suzuki GX 125, Honda CB125 TDC '83, Honda ntv 600, Kawasaki ER5, Kawasaki ZZR600, Aprilia RSV 1000 Mille
Now own: Ducati 848 evo

[YBR Ric]

The YBR's have never had a recall

Well it was over 27*c for most of the day yesterday and my YBR was parked up out in the sun after cleaning it for over 6hrs whilst I went out for a ride on my other bike.

It started first press of the button (after cycling and finishing its initial start up check) just like in winter when the temperature drops below freezing.

Just how hot does it have to be before for this 'well known' problem manifests itself?

[simonjb]

It doesn't have to be that hot, the tank has felt hotter than it does today, without issue. I think it is a cumulative vaporisation issue, in that it takes a while - mind you my tank was fairly empty; so I filled it up yesterday and am waiting for the bike to heat up now to test it.

What year is your YBR, Ric? Googling the issue yields about 3 forum posts on here, and a few on other sites - It's been between 24 and 28 the last few days here.

Yamaha came back and told me to contact a dealer to get it checked out and said if there is evidence of a manufacturing fault they'll pay for it to be replaced on goodwill, so high hopes for that.

Though I am awaiting the results of brimming the tank, as of course its far harder to heat up more petrol. It seems that a small number of the YBR's out there are having this issue, but it only seems to be certain pumps, and I've only found cases from 2007-2009, and mine is a 2008.

Also does anyone know if a replacement fuel pump for the 2009 onward, will fit my 2008, as it does look identical and the housing is 30mm?

EDIT: No such luck with the full fuel tank - all it did was delay the issue.

[simonjb]

Found about 6 cases where replacing the fuel pump has solved the problem, and I've noticed an unusual whine from it that started a few weeks back and I had totally forgotten about. So I've managed to find and buy an aftermarket replacement for £26 + £10 shipping from California, just gotta spend 2 weeks nipping between shadows.

Thanks for the help, I'll post back here when the pump is fitted and I get a chance to test the problem - but given the number of cases, I'm confident this will solve it!

[Dave M]

[simonjb]

[YBR Ric]

Mine's a 2007 -2009 model, manufactured in 2009. A lot of changes were made to the 2010yr onwards model.

Are you ensuring the amber light extinguishes and the prime cycle has completely finished before attempting to start the motor?
If there is difficulty you might like to try holding the throttle 1/4 open whilst thumbing the starter and once it has started and a little warm, turn the ignition off and start it again correctly with the throttle fully closed and untouched so the TPS unit output is what it should be.

The whine should be from the fuel pump priming which will always be audible, although it's quite possible that the increased temperature can result in a slightly longer priming cycle. Running the tank low can result in premature damage in some pumps as they generally rely upon being submerged to aid their cooling as well as a constant internal flow of fluid - one good reason why you should not allow the tank to run empty.

A louder noise or screech can often be the result of it needing to purge air during the prime cycle - but this should only occur during tank removal when some fuel is lost from the injector side of the disconnect.

Whenever the kick starter is operated it should always start the prime cycle to ensure full fuel operating pressure (no matter how many times it is depressed). Repeated gentle kick starter use may help overcome this problem by ensuring a fully primed system before a firm kick with the intention of actually starting the engine is used. Obviously won't cure a faulty pump, but might help if its just a temporary heat induced glitch!

[simonjb]

Yeah definitely waiting for the cycle to finish and the engine light to disappear, but the pump simply does not even engage - when it cools, it engages but seems to struggle to do so until it is completely cool. I've tried using the throttle to pull more fuel into the system, but that trick only works when the fuel pump is running even a little, there's not enough in the lines to turn the engine more than three or four times.

Also the tank was about a fifth full, have never let it empty and always use Shell as I've heard the super market brands aren't that great at keeping the engine clean. Tried the kick start trick as mentioned on someone else's post on another forum, but the fuel pump again, does not even start. I'm awaiting the aftermarket part now and given that my current one hasn't been replaced since the bike was new (I asked the previous owner) a new one can't hurt.

[simonjb]

Hi again, new pump arrived today, £12 customs and handling charge and all.

Just a little descriptive note for anyone who has the same issue:

The pump I bought is a generic one which will fit a large number of bikes, comes from the US, and you can find them on eBay. As predicted by the reviews the new strainer wouldn't fit (90 degree fitting not 180) - but the old one just needed a clean. It was a little difficult removing the rigid plastic clips but using a couple of very small flat heads I got it open and switched them over.

Just taken the bike out for a spin, fuel pump is a little louder but works brilliantly, not a hiccup, and the bike has got it's old kick back (naturally a very small one being a 125) but it works great.

Thanks for the help guys, if this ever occurs on the forum again a replacement fuel pump seems to be the only solution.

[JCW4B]

Hi simonjb,

I have the same problem and a replacement pump is on its way from California thanks to eBay.

Are there fitting instructions with the replacement pump ? Looking at the old part, it looks pretty difficult to take apart.

Thanks,

[Enaver]

Had the same problem with my Yamaha Ybr 125 2007.

I had the problem for 3-4 years, stopped working every now and then but I saw it as too much hassle to fix. However half a year a go it stopped completely for 1 week.

I rang around some Yamaha dealers, most said no. However one in West London got a brand new Fuel Injection from Yamaha for free for me and I just had to pay for the labor. Even though there wasn't a call back it was a known problem and Yamaha were happy to give me a new part for free, worth remembering.

Now works fine and get a great swirling noise when turning it, nice to hear the fuel injection nice and strong.
____________________
Honda CBR 500R Black
Yamaha YBR 125 Blue

[simonjb]

Enaver, that's great news to hear! My new fuel pump is still working a charm!

JCW4B, I don't remember there being fitting instructions. But if you have a haynes manual then there's some useful stuff in there, if not, definitely get one!

Once the pump housing is out, the only issue is getting the plastic casing open, there are 3 pry clips that are really tough but I managed with help (4 hands definitely useful) to get a couple of small screwdrivers in them and pry them off. Once the old pump is out, you just have to get the strainer off by prying off a metal locking disc (very small) also can be done with screwdrivers, but it can be cut with a wire cutter as the new pump comes with one. The new strainer is the wrong type, but give the old one a clean with some spare petrol and it'll fit onto the new pump fine with the new clip. Putting it back together is a piece of cake!

Best of luck, feel free to post any questions!

[cb1rocket]

Can you link me to fuel pump you found on eBay?
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Honda H100S2 Rebuild - https://www.bikechatforums.com/viewtopic.php?t=253852

[JCW4B]

Here is the eBay link

https://www.ebay.co.uk/itm/New-Intank-30mm-Fuel-Pump-for-Yamaha-YBR-125-YBR125-2007-2012/290972558793?ssPageName=WDVW&rd=1&ih=019&category=177780&cmd=ViewItem

[kevinheb]

Can I ask what symptoms you have?

When I try to start I get an error code of 19, and then have to turn off and try again.

I quite often have to press the ignition before the engine starts, and once it starts its fine.

Is this the same problem that others are having or is it different?
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YBR 125 (sold) > YBR 250 (sold as spares/repair) > F650CS

[JCW4B]

As mentioned in previous posts, when the ignition key is turned on the bike goes through the start sequence with the orange light coming on for a few seconds. However the fuel pump does not start (there is no noise at all), and then when the electric start is pressed, whilst the engine turns over it will not fire up.

So I think you have a different problem.

[simonjb]

kevinheb, the problem most of us are having/had doesn't produce an error code because the only issue is the fuel pump. When I had this problem, I found that power was going to the fuel pump as it was supposed to when the the pump is meant to prime, but the fuel pump was simply not running, despite getting power. I recommend starting a new thread for your issue.

I just checked that ebay link, and it seems that felcoproducts (where I got mine) are stocking them in the UK now? Which is helpful to anyone who has this problem.

[JCW4B]

A quick update on my fuel pump problem. I bought the replacement pump from eBay and fitted it without too much trouble into the fuel pump and petrol gauge float assembly.
When switched on, the pump primed no problem but the bike still wouldn't start. After much investigation it turned out that whilst the pump was working fine, the fuel pressure was too low. Further investigation showed that the new fuel pump was not seated quite correctly in the plastic housing and pressurised fuel was escaping back into the fuel tank. There are a couple of rubber O-rings that fit over the output nozzle of the pump - make sure you fit these correctly otherwise you will have the same problem as me !

[simonjb]