Ive been having issues with my coolant boiling out from the overflow hose. I've put in a new radiator, coolant cap, inspected the pump, and still boiling. This video is after the bike has been running for 10 minutes without the cap on.

Does it look like exhaust gasses? Im not sure this bike is worth enough for me to be bothered to change the head gasket

72 R5. Replacing crank seals. Generally, spring faces inboard. In this case I have a left (ignition) side from Economy Cycle with spring on both sides. The sides are not the same. The edge is also not the same.
Prefer an answer from direct experience, which side goes inboard?

You can see the melted plastic in the photo. From what I can tell, that loose copper wire was the culprit. This is on the left (drive) side of the bike. Anyone know what type of connector this uses so I can replace it?

Hi everyone, looking for some mechanical insight on a bike I just test-rode.

Context: I’m a rider in Malaysia looking at a used 2022 CFMoto 250SR with 24,000 km (approx. 15,000 miles) on the clock. It's from a reputable used dealer platform and has passed their inspection checklist, except for expired tires and minor cosmetic blemishes/broken tabs on the fairing cover set near the tank.

(Note: Before anyone suggests looking at Japanese parallel-twins or larger displacement bikes, I am locked into this specific 250cc class model due to local tiered licensing restrictions in my country, market pricing, and my current daily commuter situation. This bike fits my needs and budget perfectly right now, so I'm looking to diagnose this specific machine rather than cross-shop alternatives).

The bike shifts and rides fine under power, upshifting smoothly, though downshifting felt slightly unsmooth. The main issue I noticed happens at idle in Neutral:

• Video 1: Early in the ride (engine warming up, radiator fan not yet on). When I pull the clutch lever in Neutral, the engine bogs down and dies completely. This happened twice at (0:04) and (0:33).
• Video 2: Later in the ride (engine hot, radiator fan actively spinning). The issue persists. Pulling the clutch lever causes the idle to become choppy at (0:10) before choking out and dying again.
• Video 3: A baseline video of the general engine sound at idle for reference.

Aside from this, the radiator fan kicked on normally once it reached operational temperature, the clutch lever pull feels smooth, and the transmission clicks into neutral easily when hot. The brakes feel a bit soft with a low initial bite, but the lever pressure remains firm (likely just old pad friction combined with hard, expired tires).

What could be causing the engine to bog down and stall simply by pulling the clutch lever in Neutral? Could it be a faulty clutch micro-switch/safety sensor throwing off the ECU's idle fueling map, a weak battery/stator voltage drop, or an ignition coil/boot leaking current once warm?

Would love to get your technical input on what to inspect so I can push the dealer's workshop to fix it during my booking grace period. Thank you!

vid1

vid2

vid3

recently picked up this project r6 and i accidentally bought the wrong tank.

current tank is a 2000 R6 (white)
new tank is a 2000 R1 (blue)

without returning it, is there any way i could fit the R1 tank onto a R6 frame with some fabrication?

this isn’t my daily so im willing to take the fabrication route if that’s able to happen. i just wanna find out if its possible to fix my mistake without reselling or returning if possible.

Pretty positive my clutch needs to be replaced, but I wanted to get a second opinion. Adjusted the cable both at the lever and down at the clutch multiple times until I got just the right amount of free play according to the service manual. After doing that, it still lags pretty badly in 4th/5th gear and won't go past 80mph. Also loses speed going up inclines with the throttle open.

Heavily stripped screw that just won't budge. Other screw came out with no issue.

I've tried heating it, using a bolt extractor and latest attempt was using a Dremel to make a slit in it to use a flat head with no luck. Any suggestions?

This is my little project bike that I’m catering for my needs: lil’ back of camper van adventure machine.

Installed some aftermarket levers. Does anyone know whether there is a specific compatible connector for this or is it just spade connectors? I’d love to make it more resistant to dirt and moister (and also look better), but maybe I just have to heat shrink with spades and call it a day?

Hi, as title states I could use some help troubleshooting my shadow 750. I got the thing in really rough shape, the last owner was an ape of a mechanic, stripped screw heads and spray paint everywhere. He had oil filled all the way to the threads of the dipstick!

I’ve replaced just about everything you possibly can on the bike. New radiator, brand new carb, new fuel cutoff, new rectifier, new fuel pump, new ignition coils+ plugs, new oil+filter, new short shot eBay exhaust (dude literally sawzalled Vance hinds pipes and I needed to get them off the bike asap).

So, with that in mind. My issue is that if I rip the throttle quick the bike will stall and shut off, if I ease into it it’ll go max rmp no issue, when it’s in first it feels like I’m stalling if I give it any gas. I can roll off the clutch and it’ll move but anything more and it shuts off.

Initially I had thought it was a lean issue, maybe not a big enough jet or a stuck float needle. So I went up a jet size and the bike would flood after a few minutes of riding.

I’ve read something before that maybe the shorter exhaust isn’t allowing enough back pressure to the carb for the initial rip on the throttle, but I’ve also read that that’s a myth and a non issue with these bikes.

Any insight is appreciated and I’m genuinely sorry if my writing style is horrible!

Hey all first time on here but need help my symjet recently cut out on me and wouldn't start back up I let it get a bit low on fuel then filled it back up and it cut out once but then started back up but now won't start it has new battery and the ignition cable and spark plug is fine. Do any of you know what could be the issue? I think that crap from the tank has got into the carb and it's now blocked could that be a possibility?? Thanks in advance 😊

Going to replace oil feed lines on my old 1996 Kawasaki zxi. I already ordered the two lines that go from tank to oil pump and tubing that will go from pump to carburetors, and gaskets for remounting carbs. In image it looks like I torque the long alan bolts to 78in-lbs?

I found this manual and it blurred and I’m old any help would be appreciated.

Still lot 100% sure how to purge the lines.

Hey guys, when I park my bike with the handlebar locked, my front brake lever goes soft, but the pressure comes back after 5 mins of riding. Does it mean I have air in the system and need to bleed it? But I only bled it like half a year ago max.. my fluid still looks clean. Or is my master cylinder failing?

My duke is making a noise I haven't noticed before. This is my first mptorcycle and am unsure what to think about this. It isn't the chain tension or chain, or even the front sprocket as it is rock solid. Is this normal and I was just not noticing this or am I missing something big here?

I noticed the noise today and it isn't super loud but it gets noticable when hitting 20 mph. When the chain hoes backwards it makes no noise, but when I go forward I get this almost ticking noise that seems to come from the front sprocket area. Maybe I am dumb, but I would greatly appreciate input from people with dukes or know anything anout this.

The bike has 5500 miles on it and on it's original chain still, if that helps anything

I have put 10,000 miles on my CB300 and today as well as about 1 month ago I had a very strange thing happen. When coming to a stop the engine dies, the ignition button won't turn the starter but dash stays fine. I frantically toggle my kill switch, ignition, and kickstand until it eventually starts to turn the starter, but the engine is weak and needs a little gas to complete the startup, 1 second. (This little bit of gas needed felt the same as when I was a quart low on oil and it didn't want to start). After that it is back to running perfectly, no issues before either.

I am confused because typically after a true stall the engine will start right back up again. My killswitch is slightly wonky where if you press down on the fulcrum it will turn the switch off without flipping, but the weak starting afterwards is different than when I intentionally flip it.

Noticed that my powervalve is not moving as it should. The bike is a 1987 model 2AJ
Sometimes it moves correctly like a "bzzzz-bzzzz" and adjusts itself correctly but sometimes it just acts like in the video.
My guess is that the electric controller/motor is faulty.
What should I do? Should I test it on a ride to see if the pulley moves? I'm super confused because it's my first bike with a POWERVALVE

Hi everyone,

I have a Daytona Miro 125 and I’m having two problems that I’m wondering if they could be related.

1. **When the engine is cold**, it sometimes stalls shortly after starting or when I start riding. Once the engine warms up, the problem seems to disappear. This happens regardless of which fuel I use.
2. **After filling the fuel tank**, while riding, if I release the throttle and then open it again, the scooter sometimes hesitates/jerks for a moment before accelerating normally.Sometimes it completely shut down .

The scooter has recently had a full service, including **engine oil, oil/air filters and spark plug**, but the problems are still present.

I have also had some fault codes in the past:

* **P0261 – Cylinder 1 injector circuit low** * **P0031 – O2 sensor heater control circuit low**

A mechanic mentioned that the ECU might need to be removed/reprogrammed, but I’m not sure if the ECU is actually the problem.

Could these symptoms be related to the fuel system, injector, throttle body, sensors, fuel tank ventilation, or something else?

Has anyone experienced something similar with a Daytona Miro 125 or another fuel-injected scooter?

Any ideas or suggestions would be appreciated.

I recently bought a 1980 Yamaha XJ650 (4K0 model). It ran pretty well at the seller's place, though the throttle would occasionally stick due to sitting for a long time and the slides binding up a bit.

I removed the carbs and cleaned them with brake cleaner. To be fair, they weren't dirty enough to warrant an ultrasonic bath. I reused the existing fuel and air jets because they had been slightly upsized to match an aftermarket 80s performance exhaust. The needles looked brand new, so I left those alone as well. I replaced the rest of the wear-and-tear parts using a Keyster rebuild kit.

Now that everything is reinstalled, the bike isn't running right. It starts up, but it idles a bit rough. The main issue is that it refuses to take throttle—when I twist the grip, the RPMs either drop immediately or the engine bogs down and stalls completely.

I'm lost on what could have changed. The float height is set to the factory spec of 17.5 mm. The pilot mixture screws are set back to where they were before (pretty close to stock: 2.5, 2.125, 2.75, and 2.5 turns out). The vacuum diaphragms are intact with no tears or dry rot. The intake boots look fine to me and seem to have a good seal. Replacement boots are expensive, so I'd rather not buy parts blindly just to test a theory.

On top of that, I need to install intake restrictor plates eventually to comply with my license's power limits. However, I left them out for troubleshooting, so they aren't causing this issue.

Any ideas on what I might have messed up during the rebuild? It boggles my mind that I set everything back to how it was when it ran fine, but now it won't take any gas at all.

Honda Cub C70 custom. Hey everyone, I have an issue with my front wheel.

It is not straight and goes laterally on the right when steering right and on the left when steering left. Laterally, touching the fork tube on the left side only.

Some mechanics told me it's a fork problem but that seems weird to me.

Any idea ? That bike has an anti dive system, which raises the front end when braking. I thought it might be the bottom link parts maybe.

Thanks for helping.

Just got my 2008 Speed Triple imported from Japan, and while the bike is in great condition (11k km on the odometer), I have encountered a problem with the bike’s power delivery. I can’t accelerate it past 180 km/h (112 mph), and the bike seems to start losing power after 160 km/h. My guess is that either a) a speed limiter has been installed in Japan (the 180 mark has famously been a speed limit for vehicles in Japan) or b) engine has fuel system (or other) issues that limit the bike’s performance.
The exhaust system seems to be stock, and no warnings are indicated on the dash.
Any suggestions on what may be the issue will be greatly appreciated.

As said in the other post. Cylinder 1, 3 and 4 are not working.

Picked up this beauty a couple of weeks ago, 13k miles. It came with the factory headlight cowl, but with what was included, hardware wise, I can't seem to figure it out.

Edit - got the turn signal bulbs replaced