Hi there. I have a Yamaha YBR 125 on an 07 plate. It's the fuel injected model. Its developed a serious and dangerous fault that I just can't seem to find an answer to on the Internet... When riding along, doesn't matter what speed, or time of day (it's happened at night and day) you'll be driving along as normal then BAM it just cuts out on you and the engine management light (EML) (the yellow one on the dash that comes on and goes out after a few seconds every time you start the bike) just flickers... Then BAM it'll just pick up again like nothing's happened! It did this to me 6 times in the space of 1 duel carriageway yesterday. The bike also failed to start on me one time which seems to have started this problem. I'd left the bike outside on a really hot day for 12 hours and the EML came on as usual and went out, but the usual 'priming' noise wasnt heard. And of corse, it wouldnt electric, kick OR bump start. How annoying. It did have a similar problem about 3 weeks ago. Where it would just cut out when driving. So I gave the bike a full service. Plug, oil, WD40 all connectors, etc etc etc. the problem went away for 3 weeks but has come back with vengence. I daren't ride the bike now thru fear of it cutting out and just never starting again. OR it cutting out when travelling fast and it throwing me off into on coming traffic. Any help would be great as i really like this bike but I need to get it sorted! Thank you!

SOURCE: 03 YZ not starting

I don't think this is a float issue. One way to check is to turn the gas off, take the bowl off the carb, hold the float up, and turn the gas back in. If fuel flows, the float needle is toast. It sounds suspiciosly like a worn topend, but it could also be a clogged jet ot fuel filter, or a faulty CDI.

SOURCE: YZ not starting

I don't think this is a float issue. One way to check is to turn the gas off, take the bowl off the carb, hold the float up, and turn the gas back in. If fuel flows, the float needle is toast. It sounds suspiciosly like a worn topend, but it could also be a clogged jet ot fuel filter, or a faulty CDI.

SOURCE: My 9 month old Yamaha YZF-R125 has been cutting

Sounds like you have either got water in the system or poor connections.
You can use something like dielectric grease on each connector. It is a bit of a pain having to open and close each connector on your bike, but once you've done it, you shouldn't need to do it again for a long, long time.

Sudeep Chatterjee

• 3267 Answers
• Posted on Sep 18, 2009

SOURCE: 2007 Mt 03 Cuts out

It seems as if the air-petrol control nozzles are not set appropriately(i.e. not tuned properly). Another possiblity is that the ignition switch has got some loose connections, thus cutting off electricity to flow(only ignition wiring) thus stpping the vehicles engine. Even if it gets grounded to the body of the bike, the result will be **** you have explained. When stationary the engine will not stop since there isn't sufficient vibration to dislodge the wire..sodeep

SOURCE: Hi. While riding my BT1100 the diagnostics

check for a short in the wireing harness trace signal wires from relay to lights see where the break is look for any spots that may have rubbed through