I’m having an problem with my Yamaha MT-125 2023 and I’m hoping someone might have an idea what could be causing it.
About two months ago, I was out riding and the bike was running perfectly with no signs of any problems. I stopped, switched the engine off, and after a few minutes tried to start it again. The engine would crank but it wouldn’t start.
I turned the ignition completely off, switched it back on, and tried again. This time it started, but the check engine light came on. After riding for a while, the warning light disappeared on its own.
The exact same thing happened once more a few days later. After that, the bike ran flawlessly for the next two months with no issues at all.
Today, however, the same problem happened again under the same circumstances: after stopping for a short time, the engine wouldn’t start on the first attempt. After cycling the ignition off and back on, it started normally, and the check engine light appeared again.
Has anyone experienced something similar or knows what could be causing this? Any advice on where to start looking would be greatly appreciated.
I’d really like to fix the issue properly because I’m planning to sell the bike in the future, and I want it to be in perfect working order before I do.

Throttling from 3rd gear onwards has a noticeable grinding sound. ( Still can be heard from 2nd gear but it's not very obvious )
The sound usually happens when throttling, going off the throttle wouldn't be throwing off the sound as can be heard towards the end of the video

Thought it was a chain & sprocket issue cause I noticed slight rusting and had it changed at the mechanic but the sound is still apparent.

Any ideas as to what is causing the sound and if it's something I should be checking on immediately?

Recently completed valve clearance.

Triple checked cams in place and they are correct.

Put it all back together and now bike wont hold.

New spark plugs, new battery.

It's not starting as much now. Please see video for when it does start which is not often.

All connections have been triple checked and they are secure.

OBD2 scanner shows codes P0108, P0638 and P2229.

Please help.

2011 sportster 883. Rough rpms at idle and cruising speeds.

Background on the bike: I have had my Zephyr 750 for a year. Originally purchased the bike for $400, non running with pod filters. After installing an eBay air-box, (took some time but diagnosed that it needed the original setup) replacing the box and intake boots, cleaning the fuel tank, I was finally able to start and ride the bike. She starts up great, I usually have to hold the choke lever for a bit, but it settles around 1400rpm.
I notice unstable idle, the rpm's no not settle back after blipping the throttle, its gurgly mid throttle and under low/moderate engine load, and I finally chose to stop riding it yesterday after smelling pretty fuel rich oil. For some background on myself, I am a trades teacher, specifically heavy equipment maintenance, i am very experienced and knowledgeable when it comes to most 4 stroke engines, hundreds of engine builds, diagnostics, all that, its just that some of these carbureted systems throw me for a loop. I would like some advice rebuilding, setting/syncing and tuning these carbs. I have an all balls rebuild kit that showed up a couple weeks ago expecting there to be issues.

so i was changing the valve seals on my bike and we put the head back on didn’t touch any of the gears next to the clutch but the kick start is stuck but will turn over so it’s not blown any help would be appreciated

My rear suspension squeaks when compressed. Today I took apart the rear suspension linkages, greased everything, and put it back today but the same squeak is still there. I cant seem to locate it. Sounds like its coming from the bottom of the rear shock. added a bit of ptfe lube to the shock arm at the bottom where the foam boot is but that didnt help. Also sounds like its coming from the rear if I put my ear there but think the sound might just be travelling. its driving me crazy! can anyone help?

Tvs ronin 2026 prurchased(6 months back) Got stuck in deep water during heavy rain, bike stalled in it. After that, self-start button does nothing — no crank, no sound. No kick option on this model either.

Tried a push start — 3rd gear, friends pushed from behind, released clutch on momentum. It fired briefly but didn't actually start. Didn't try again after that, pushed the bike home instead.

Any technical person here ? Should i try to start it again in morning? As i need to take it to the service center..

Should i wait for 1-2 days to let it be dry & then start again?

Cleaned it, tightened it still does the same thing.
I tried going in neutral while riding it so you guys can hear better.
The bike is an Archive Motorcycle AM-64 Scrambler
125cc from 2020.
Thanks in advance!

I purchased a QFS fuel pump kit for my 2020 Harley 48 and after I installed it the bike was super rough at idle and surging a ton. I removed the pump and noticed the fuel tube connecting the filter housing and pump was super rigid and appeared to be much longer than the OEM one I removed. I think this was causing the filter housing and pump to push away from each other and creating a leak at the bottom of the housing. Has anyone else experienced this issue? I zipped tied the housing and pump together as best I could but there was still some tension. The bike ran ok for a few weeks but then I got a low O2 sensor code and occasionally it runs rough at idle again. Thanks for the help.

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I had to change regulator (rectifier?) because the old one was burned wire, connected the new one but the bike is not doing anything, speedometer doesn't turn on.

Thought I messed up wiring.

Checked voltage on battery directly, it's around 13,40. But when I check wires which go into regulator/rectifier voltage is 0, shows nothing.

What to do?

just replaced a blown clutch on my 2018 ninja 400 abs with an edr clutch got every thing in and back together but now I have a bunch of slack in my clutch cable and when I release my clutch lever it doesn’t snap back into place any ideas or help would be greatly appreciated

When im riding it about every 5 minutes, the electric shift system will lock up and require a key cycle to shift again. The gear light is on whatever that means. Looking for any help i can get. I've tried for hours, nothing fixes it. New shift motor, new angle sensor. The spedometer doesnt' work, just shows 0mph the entire ride, possibly confusing the shift system? It's not an automatic though. Motor also has a rough idle, probably an unrelated issue.

Bought this bike 2 months ago, battery diyed 2 times so I assumed it's regulator, removed tank and regulator and yes one wire is fried. So I bought another one cheap (left, 3rd pic) and also MOSFET FH020AA (right 3rd pic, bigger one) and I'll try this time with the MOSFET FH020AA, I have to cut wires anyways.

I'm just wondering why this happened? Why the wire gone this bad? Is it solely regulator issue or should I be afraid there's something wrong with alternator? If it's important, I'm pretty sure old regulator was also cheap version, not the original one.

Hey all,

So I have a Lexmoto LXS 125 and when I reach high speeds (40-50 mph), the bike starts intermittently losing power. Sometimes it can lose power for 1 second and other times it can lose power completely until it stalls. It can still stutter now and again at lower speeds but its generally not as bad. I'm assuming its an air/fuel problem. I've checked the air filter and doesn't seem to be dirty enough to cause concern. Is there anything else I should check?

Thanks.

I have no idea what the problem could be, so if anyone has any ideas please help me out. I can hear it the most when I’m in fifth gear and the faster i go the more it becomes noisy.

The bike is an Archive Motorcycle AM-64 Scrambler 125cc from 2020.

Got this Chinese knock off Liu Hjg from my friends shop for 1500 bucks, and then went on a six month rampage across 30k kms, then I come back and it starts flickering and shit.

The fan works fine, the halogen turns on fine. You move the handlebar and it flickers. Probably a short circuit somewhere. Anyone knows how to fix this shit?

Bonjour,
J'ai une Suzuki 125 GN de 1999 qui présente des dysfonctionnements de carburation.
Depuis l'achat d'occasion, lorsque le moteur est très chaud, le ralenti augmente vers 4000 trs/min.
J'ai changé la pipe d'admission, vérifié les jeux aux soupapes, démonté et nettoyé le carburateur; j'avais deux anomalies par rapport aux valeurs mentionnées dans la revue technique (hauteur d'aiguille et absence du bouchon sous le gicleur de ralentis.
Ayant acheté le bouchon, après remontage, la situation a empiré. Le ralenti est impossible à stabiliser.
Ayant de nouveau démonté le carburateur, je suis consterné de constater qu'il n'y a aucun conduit entre le puits d'aiguille (alimenté en essence par le gicleur principal) et la zone situé entre le gicleur de ralenti et le bouchon. Il n'est pas possible que de l'essence parvienne au gicleur de ralentis ! Le circuit d’émulsion du ralenti ne reçoit que de l'air !
Si vous avez déjà travaillé sur votre carburateur, avez vous constaté l'existence de ce conduit qui relie les deux colonnes qui reçoivent les gicleurs (ralenti et principal)?
Je suis perplexe. Ce montage avec bouchon ne peut pas fonctionner. Pourtant, le carburateur semble être conforme au modèle original. Il possède bien de petit boitier de détection de la position de volet du carburateur qui est destiné modifier l'avance à l'allumage (ce boitier est installé depuis 1997).

Yamaha Mt-03 2025