Tpex Rath

Hi there, long time no see, I finally upgraded my trusty steed, and then my course of electronics curse jumped bikes. So I have a '99 Thundercat about 60k miles on the clock, she was running okay and I added a LED strip, after a few more months the battery started dying on the regular. so I disconnected the strip but the problem persists, Bought a new battery, same problem, I have tested voltage when running at 3000 rpm and higher and there is an increase to the battery, so it doesn't seem to be the regulator or stator. There is no draw when the ignition is off. The only problem I can seem to find is when I have my headlight on, the voltages steady drops, instead of increasing, even at high revs. it's the same bulb that I bought the bike with and that she ran fine with before the problems started, and the correct bulb for the model (55/65w) Another issue (previous owner pointed it out) the rev meter will sometimes climb to 8000rpm and then drop again when the ignition is on, but engine is not running, then when running the rev meter will stick to 0, the only way to reset this is to close the throttle completely and then open again, then it will read correctly for a time. So I'm at a bit of a loss, and also getting tired of being stuck on the side of the road, any ideas/help would be appreciated.

That was a fun lesson! Amazing cornering on the one side and almost nothing on the other!

So I took the ignition coil off and tried to test it according to this but couldn't get any usable readings, but I did sand down the connectors as they where quite rusted, maybe they where not making contact so it was arcing? Anyway also cleaned the spark plug for good measure. Too her for a ride and the problem was gone!

Doubt it, hardly use it down here, but I'll see what using it does. that sounds like a plan! Will do! Road it to work shortly after my first post, no problems, but now on the way back it started again, I did think they sounded electrical.

I have a similar model myself, will be watching this with interest

Looks interesting, can't wait to see the end product

Hi all again, Why do I always get the weird problems? my YBR125 ('09 Carbureted) has developed this clicking sound and slight loss of power (misfiring?) while driving, and only when hitting revs around 6k-7k, in any gear, the rev-meter also goes haywire above those revs (red lining on the meter, but engine sound doesn't match) Now I tried to replicate this while on the stand, back wheel free and bike in gear (tried all gears), it doesn't happen, only when the bike is physically moving and I'm hitting around 6k-7k revs. chain looks fine, I have done cursory inspection.

I see thank you. I didn't get around to checking the other voltages, just as well, there are 3 different blue wires going through the loom O_o I found that the brake/back light was the wrong way round, now the ride light it dimmer then the brake light, and everything is working.

You telling me! bane of my life! I checked the voltages where they would go to the bulb, (replaced the bulb with the multimeter leads) same with the switch. I suspect, somehow its lighting both elements in the bulb, didn't think to check last night, will check tomorrow or Sunday. I checked the earths (black wire right?) to both the body and the negative terminal of the battery, and both show a continuity.

Finally got around to it, results where mixed... USED this as a guide Testing between all the blue wires said they where okay, Between switch,aux bulb, back right light, dash lights. Weird thing was the voltage: To the Aux Bulb 1v - 0.8v To the Ride light 0.6v - 0.8v To the Switch 3.2v - 2.8v And the plug connection below the switch 4v-3v Now this tech diagram says they should all be 12V Anyways I tried to skip the connection in the body, by putting a new wire between the switch and the aux bulb (like so, bright green wire) this makes all three lights work, except the back light is now on full blast, which means one can't see the break light.

Okay turns out yours truly is a right royal dumbass, had the multimeter's leads plugs into the wrong jacks, wile testing again the indicators started working...

weird, the Amperage also shows as one on the battery from 200u right down to 200m

Battery has been pretty much dead for a while, but they it worked fine while the bike was running, and all tests were of course done while it was running. The wiring is fine till I get to the sealed up main areas where they all collect and do to the various little boxes. I'll check the amperage tomorrow.

Hi All, again electrical problems, bane of my life... My YBR125 '09 stood outside for about 6 days, exposed to the elements, and now all the indicators have stopped working. None of the bulbs are blown, and I checked each connection, it's putting out 0.03 volts to each light. I'm sure the relay used to give a slight ticking when a indicator was on, but now it will give a slight tick when the indicator is selected, and the amperage goes from 0 to 1 Do I need to replace my relay? can I break the seal and fix it myself? Thanks in advance

Sorry life took over and I had to live with the problem, eventually hooked up a 9V Battery with 2 LEDs to the back with a manual switch, will give it another look over, thank you.

It used to be like that, now it doesn't give any power, tested the wires all the way before the bunch up and go into a covering that carries them to the ECU, with a multimeter Why the hell did Yamaha connect them in series!

Nope, reconnected the the standard bulbs. it did work if i moved the wires around, but now nothing, can't find the fault.

Would it be possible to reroot the back ride light to run off the same wires as the main headlight without any problems? They both run on 12 volts don't they? No, back ride light doesn't work at all, neither does the front, only the main headlight works, and the indicaters and break lights of course. Why? because this looked too cool I never learn my lesson.

Not under the tank is it? not looking forward to taking that off.

I think this all started when I tried to replace my front "dim light" with a LED strip, it worked perfectly till I put the face back on (and looked rather sexy too I might add) Anyways, It seems the back ride light (the one that stays on all the time, so other road users can see you from behind) is connected to the front in series, becuase when that doesn't work neither does the back, I checked the back bulbs, both fine. of course I tried putting the orginal front light back but it seems I may have damaged something deeper, both lights would flicker every now and then with moving of the wires and vibrations. Went back today with a multimeter with the intent of stripping the wires as I assumed it had worn between the plugs, but even cutting back into the obviusly healthy wire (before it goes into the tube to the ECU) provides no reading. replaced the plugs anyway, still no change. Any ideas? There is only one fuse on the bike isnt there?

Name: Yamaha YBR 125 (2009) Date Added: 18 June 2014 - 03:58 PM Owner: Tpex Rath Short Description: None Provided View Vehicle

Hi all, my name is Leighton, I'm from South Africa, I own a '09 YBR125 that I brought second hand, it's my first bike if you don't count the scooter I had before Love riding, don't think I will ever give it up, at this moment I'm recovering froma nice bunch of road rash, or as well call them here Roasties. Cheers!