lemur

Use a torque wrench and locktite, Ti bolts don't like to be over-torqued 👍

Title says it all, buddy is trying to local source a 10mm x ~105 mm engine bolt because the original aluminum one broke. Note to owners, don't over-tighten & might want to stock a spare something that works, seems the alloy bolt has a prior history of failure.

That would be the correct way for the nut to tighten as a result of the engine firing, if the engine had to spin in the opposite direction it would need a reverse thread. If it had a reverse thread it would need something to positively stop (locking washer) the nut from loosening off in operation. Nobody puts a left hand thread on anything that does not absolutely require it, too expensive.

Not a very expensive part, If it has 3 wire connections, 2 of them will be AC input tabs, one will be a DC positive output tab and the mounting point will provide the chassis ground or DC negative.

Your engine outputs alternating current and the fan runs on direct current, the little black box connected to the fan will be a rectifier/regulator. Function is to convert the AC to DC and typically to limit the voltage so the fan can run on 12 volts DC Power output from the engine alternator is called 'dirty', voltage will be all over the place, job of the rectifier is to change AC to DC and the job of the regulator is to limit the peak voltage. Rectifier uses Diodes ( semiconductor that allows current to flow in one direction.) Regulator uses various transistor semiconductors to send excess voltage to ground and dissipate heat which is a byproduct of that process.

Could not make this one myself but the video makes it look like one very slick ride, lots of footage here for those with interest:

Lithium batteries don't perform well in cold climates which is one reason why they don't rate them in CCA cold cranking amps, the battery RC spec is under optimum test conditions.

Motor should not draw more then the 1200 watts or there is a problem. I have one of the smaller ones and that's what made me notice the 130 amps, amperage numbers like that is the battery reserve capacity. It's a value based on the time the battery can run before voltage drops to unusable (differs for lead acid or lithium) lithium holds voltage longer and then drops faster compared to a lead acid battery

Oset 20 motor spec is 1200 watts at 48 volts watts = amps x volts amps = watts / volts 1200/48 = 25 your 1200 watt Oset 20 motor draws a maximum 25 amps @ 48 volts

The only wiring schematic I could find does not show a red/yellow wire anywhere. Does your bike still have all stock electrics and breaker points ignition or has it been modified?

Found one. You don't happen to live in eastern Ontario do you, trials riding here tomorrow if you can join us. ... to machine a cota link you would require a billet measuring 30mm x 30mm x 102mm

Titanium is the ultimate if you need to ask the price you can't afford it material. Cota dogbone is a super simple design, you could sketch it out on a table napkin and if you can machine 2 holes with accuracy it will work.

There would be a lot more demand for Cota linkage dogbones, more of them out there and the expensive stock part gets smashed easy.

If you are looking to source raw Titanium you might want to try Titanium Joe out of Kingston, Joe rides EM trials bikes and has access to a supply of used Ti material.

Lots of potential causes, a leak in a pressure line is just as likely as a blockage, does it have a battery or capacitor, does it need a bigger battery or capacitor. Fi pumps can usually be checked for performance by powering them up to an external power supply and measuring the volume of output over time.

Fuel injected? sounds like low fuel pressure at startup

Oil change costs me about 7 bucks 🤓 (roughly the same cost as one litre of race fuel) and UDT works good even in sub-zero weather ⛄ like we are about to get here very soon. If the clutch drags because of the hydraulics just raise the idle a little, that works. If your clutch makes noise and the oil drain looks cloudy that's water, water happens a lot when you do deep water crossings or the engine insides are exposed to condensation, such as riding in winter 😎 or power wash your bike.

Here is the best reference:

You are going to get a lot of different answers but the best oil to use in a 2-stroke motorcycle transmission is the oil that you can change more often. 10w30 is multi-grade oil which is 4-stroke engine oil, your engine is 2-stroke and the oil never sees engine cylinder operating temperatures, it does have a wet clutch and gears and for that I use the same thing I use in a farm tractor construction excavator which is also full of gears and wet clutch plates, UDT hydraulic oil ISO46. Others will have other recommendations but this is what works for me and it is cheap enough to replace frequently and that does more to save your transmission parts then expensive oil left in there for a long time. Only two things can pollute your transmission oil; water and dirt from internal parts wear.

Optical inspection instruments, borescope or fibrescope inspection might reveal a problem without splitting the engine casings. 🤓

Your transmission has 3 shifter forks, shifter forks are made from soft cast material and prone to wear or bending. Shifter fork 1./3. Shifter fork 2./4. and Shift Fork primary. If only some of the shifts are a problem but not all, shifter forks is what I would inspect. When a shifter fork experiences wear there will be an accumulation of metal particles in the oil when you drain it, (not likely to be magnetic) make it habit to dump your old transmission oil into a clear glass container and inspect it for fine metal bits.

Those are calculated numbers, what does a measured compression test show & Is it hard to turn the engine over even on the down stroke, or only as it reaches TDC? If this is a new or escalating problem on a used engine; remove the exhaust header pipe to do a partial visual inspection of the piston rings and barrel to make sure nothing is seizing the piston.

I always buy trials bikes in pairs and have no problem keeping at least one of them running, you need that second bike to 100% identify a sporadic failing component, that's how a dealer would fix it and keep the service cost reasonable, just swap assemblies until the problem goes to the other bike and now you know what parts to order.

I ran high test pump gas in 4RT's for nearly 2 decades and never had carbon deposits anywhere near what your plug chop shows, occasionally added 50% Sunoco GT260 for better performance and they definitely run better and cooler with higher test fuel, but never found 98 to be a requirement. Based on my mid winter riding experiences the fan should cycle for short periods even in sub-zero riding temps. ... race fuel here costs about 7$ per litre so motivation to run cheaper pump fuel is considerable.

😎 Good to see you finally upgraded from running diesel fuel 🖖