lemur

If the fan works by by-passing the thermostat switch then yes 👍 you found the problem. Replace the switch or by-pass it with a little toggle switch and operate the fan manually.

Square black box, looks to be your rectifier/regulator and that will be the part that turns AC (Alternating Current) from the alternator (stator coils) into 12 volts DC (Direct Current) required by the fan motor. Conversion to DC from AC uses diodes and diodes are one of the more likely components to fry.

Tank vent is not plugged or assembled wrong? Good idea to focus on the float needle seat and emulsion tube based on the symptoms you described. Don't over-look the tether kill switch as being a problem if it doesn't want to start after a crash or even just a shut-down. Black plug is either rich mixture or dirty air cleaner or even too much oil on the air filter element. Bikes not ridden much are in greater danger of encountering carburetor problems then the one that is ridden regularly, modern fuel has a shelf life similar to milk.

The clutch release rattle is not a big issue, the sprag bearing spring in my 2021 lasted 1 year and the sprag in my 2023 bike has completely failed after only 30 hours of service. Sadly it's more of a when it will fail then an if.

The clutch release bearing can rattle a little until the clutch is engaged. You said you pushed the button to start it? The sprag bearing in the electric starter (if so equipped) makes horrible noises when the little pawl return spring in that assembly gets bagged out, those noises will get worse until the starter no longer functions and sounds like a bag of hammers when you push the starter button, then you need to service the sprag bearing. Kick start will continue to work and I haven't found any disastrous damage from the spring wearing out. The entire sprag assembly is not a cheap part, but the spring would be inexpensive IF you can source them.

Fuel mixture too lean? Pull the spark plug after it acts up and see what it looks like. It's called a 'plug chop'

Point of engagement to full engagement is called the 'friction zone' and the position it starts should be adjusted at the brake lever adjusters. The thing that makes cork or paper clutch plates swell, stick and make noises is water in the transmission oil from leaking seals or condensation (transmissions are vented to the atmosphere), cork swells more in the presence of water. Water in the transmission oil can be seen as opaque or milky colour to the oil instead of clear oil. Yes lots of people use ATF for the transmission but I swear by hydraulic oil same as used in tractors and excavators because it has greater lubricity compared to ATF. Transmission oil in a 2-stroke engine never ends up being burnt in the engine, smoke from the exhaust has no relationship to the transmission oil. (or you have a big end seal or gasket leaking) If the clutch action is mushy that is generally caused by air in the hydraulics of the clutch actuator and your hydraulics need fluid changing and bleeding. Clutch hydraulics use either DOT brake fluid which is hygroscopic and requires changing more than once in 7 years, or they use thin mineral oil. It will be marked on the clutch. master cylinder cover which fluid you should use. When DOT fluid contains too much water there is a risk of boiling the water in the hydraulics and that will cause the brakes to drag when hot and it can introduce air into the hydraulics because when water boils it makes steam which is O2 being released from the H2O. aka worlds smallest steam engine. Too much oil (oil level too high) or dirty oil is more likely to make a clutch slip because oil gets trapped between the clutch plates and causes a hydraulic pressure that works against the clutch springs which are trying to push the friction plates together.

Grips for anything that uses a thumb throttle are the same size on both sides (7/8" dia.) don't purchase bar grips intended for snowmobiles, sea-doo or quads in error.

🤔 The grips should have the same outside diameter if they are bought in sets, it's only the throttle grip inside that is larger bore to accept the twist grip tube. If you need to build up inside the grip, 2-sided tape works but that is to make the grip not slide on the bar. Trials grips are typically smaller diameter outside compared to street grips and trials grips are available in soft or hard rubber compounds. Do you not wear riding gloves? Gloves usually work good with trials grips, required equipment for most.

Oset technical service videos can be found here if you can obtain permission to view them all: https://osetbikes.com/au/support-en-AU/electric-tech-videos/ edit: for free versions of the videos search the file names, service videos show throttle to use a hall effect sensor, failure rate for the component used in that assembly is high and the video shows how to test and repair the old unit. ... not something I would recommend unless you have a complete replacement assembly and service the old one later.

From what I've seen of electric bike fails so far they are often related to the the twist grip assembly electronics on the handlebars. Which I would guess to be a rheostat control (variable resistor). I think that is a part I would keep in inventory for replacement after a crash or for trouble-shooting.

Commutator is the rotating copper colour metal surfaces that directly contact the carbon brushes. There must be videos and/or documentation online by now detailing the steps required to test and make adjustments where you can. Meter testing for battery power (voltage) and meter testing the resistance (ohms) through wire circuits and ground wire connections back to the battery will confirm it's not just a damaged wire connection, anything that is sealed in a black box (epoxy) is generally not a user serviceable component unless there are obvious adjustment knobs or screw settings incorporated. Black box assemblies are where you need a second bike or a dealer with access to special test equipment, or known good (new) parts to swap out and ride test. Any exposed electronics can be visually inspected for burns. People with electronic repair experience are more likely to know were to look and what components are most likely to fail with age or heat from over-voltage. Wiring diagrams are always the best place to start, but they will rarely show detailed contents of anything black boxed, for sealed assemblies a second bike to swap out parts to test is unbeatable. That's how a dealer would easy find all the problems, they would use a bike to swap parts until the problem went to the other bike.

more performance oriented cdi implies more ignition timing advance. You can adjust timing at the stator to some extent or even the plug gap to a lesser extent.

Have you done an actual compression test or only based on the kickstart? Ki Is the throttle tube white or black? White is the fast tube, the black throttle tube retards the response slightly. Good chance your bike came with black tube originally like a friends evo factory bikes did.

It's the people who build the sections and tabulate results now that likely know what your regional definition of difficult is. In general terms entry level classes don't need to assault anything taller then the front wheel no need to hop, intermediate classes don't need to hop to negotiate the sections but that ability can be an advantage in sections, intermediate classes should be able to assault a handlebar high obstacle or bigger with control, advanced classes are your top riders consisting of former experts (older) and current experts (younger). Hopefully nobody sets out sections at any level that have not been tested unless you are the guy setting up world round class events, but I think we are all talking about amateur trials club events here.