konrad

There are many ways to test a capacitor, but if you don't already know how, you probably don't have the proper instruments. In that case, substitution of a know-good part is the best method. eBay is probably the easiest (not necessary best) place to buy capacitors. A prior post said, 4700uF @ 25VDC. But I have no idea if that is correct. Whatever the value is, it should be rated for 105 degrees C. Look for a capacitor specified as having "low ESR", or better yet one that specifically says it's capable of withstanding high ripple current. Some capacitors made in China are okay, but unless you have experience with a particular manufacturer/vendor, I would suggest buying a capacitor made in Japan. If you buy Chinese, buy several to have as spares.

The service manual I linked shows different wiring diagrams for the 2ED (street) and 4ED (competition) version. The only handlebar controls on the competition version are the map switch and tether kill switch. That's all you need to make the bike run.

Honda makes the best service manuals in the world! This is for a 2020 model 301: https://www.montesa.com/wp-content/uploads/2020/03/OSM-301RR-2020-EN-Web_V04.pdf Look for "Cable & Harness Routing" .PDF page 36 (manual page 2-13) shows the rear harness. Seems easy to remove. I did not see anything specifically about the 2ED front harness, but it may there too.

+1 When I would take newbies trials riding, they always asked about boots. I would recommend any boots (hiking boots, combat boots, even road racing boots) before MX boots. One local motorcycle accessory shop found that although it was not worth stocking Gaerne trials boots for trials riders (not enough of them), it was for adventure riders. I like my Gaernes for building sections. I prefer the stiffer Alpinestars Tech Ts for actual riding. It's really important to try on any boot you are considering, as there is no size consistency among manufacturers. And I've even found a "pair" of boots that felt like totally different sizes.

Translation: In case it helps anyone. My Montesa 301 2024, after installing the open exhaust, runs badly, it smells a lot of gasoline and the idle is unstable and ends up stopping. This bike requires the P71 race control unit. The P61 does not work without a lambda probe and catalytic converter.

It's your bike, but if you look at the chart, 45 to 46 centistokes is a 10 wt or 15 wt (depending on manufacturer). You really cannot judge how the old oil performed because it is contaminated with debris. Usually I think of oil losing viscosity as it shears down during use. But it's equally likely the viscosity increased due to the presence of debris. You really need to get a baseline by starting with a clean, known oil. The clickers (if any) can't fix the problem alone.

The data sheet for that oil says it has a kinematic viscosity of 45 mm^2 / second at 40* C. mm^2 / second is the same as centistokes (cSt). I always compare oils by their kinematic viscosity because there is considerable variation in how manufactures grade their oils. Peter Verdon posted a fabulous table years ago that I can no longer find. Fortunately, someone copied and reposted it here: https://norwestsuspension.com/suspension-fluid-viscosity-chart Look at the 40* C specification. As you can see, there are several oils that meet the viscosity requirement. Mostly, it depends on what is available locally. I wrote the follow specifically about 40mm Marzocchis, but there is generally applicable tuning information: https://www.ossa-efi.com/home/chassis/marzocchi-forks And BTW, 140kg is totally off the charts. You are going to require one hell of a stiff spring (front and rear) to get the sag anywhere near correct.

Sorry, did not mean to imply that just because they are pouch cells, they must all be replaced together. You can certainly replace a single pouch cell in a battery with an identical pouch cell. It's just that since most battery rebuilders work with cylindrical cells, they would likely only fabricate an entirely new battery from cylindrical cells. Which, depending on the condition of the other pouch cells in the battery, may be prudent anyway. And maybe this is why the OP wants to send everything to France?

This section is particularly relevant: https://www.electricmotiontech.com/home/ev-tech-101/battery-care-and-feeding#h.qujvukxy97fa (But the entire page will be helpful.) Making measurements is one thing. It's quite another to interpret the results, and I'm not prepared to attempt to teach that. As Chris pointed out, it's best to find someone locally who knows what they are doing. But, as you discovered, the 5.7 uses "pouch" cells and most rebuilders work with cylindrical cells. So the entire pack will have to be replaced if you go that route.

This is the big problem with electric motorsports. The battery is not something you can work on without specialized knowledge. There is no way to rejuvenate a bad cell. It takes HAZMAT certifications to ship even a small vehicle battery. See: https://www.electricmotiontech.com/home/em-epure-race/battery#h.orhjts73kbs9 It is possible to read the 5.7's BMS. See: https://www.electricmotiontech.com/home/em-5-7/5-7-bms But again, not without specialized knowledge. About the only thing you can do is eliminate the charger as the source of the problem. (A 5.7 owner contacted me saying he thought his battery was bad, but it turned out to be the charger.)

You already know what to do. Get K-Scan again and see what historical errors are stored in the ECU.

I stand corrected. Should have kept out of it.

This one was directed at you, lemur. "montesa" translated to "mountain" in English. @IBA4rt. lemur had a 2014 260. It would not have had an oxygen sensor.

I don't know the answer, but will offer an educated guess. It's likely the competition exhaust system will require the competition ECU to work correctly. However, one thing you can try is simply unplugging the oxygen (lambda) sensor from your current system. If the ECU does not immediately throw an error code, it's possible the engine will just run in "open loop" mode. This may give better performance, but it may also may run very rich and consume excessive fuel. The danger in running very rich is that it can wash lubricating oil off the cylinder wall.

May I ask in what country you reside? Was the motorcycle in question homologated for road use? Or is it a competition model?

Although jetting has an effect on rate of combustion, that's not what causes kickbacks. When a kickback occurs, the force from combustion pressure exceeded the force from flywheel inertia. Basically, the combustion pressure was high enough (too much burning too early) before TDC (rather than after TDC) to cause the piston to turn the crank backwards. Ignition timing for starting is retarded from normal running for this reason. It's possible the stator plate is too far advanced. Or it's possible the ignition system is intermittently behaving badly. Do you have a timing light, a helper, and a dark place to work? If so, you can see it the ignition timing is different from normal when a kickback occurs.

The trials bike looks heavy. Although I am heartened to see a gear-change lever. I feel having a gearbox is the way forward for electric trials bikes. I have mixed feelings about the conventional clutch. I liked it on my 4RT as it was zero-maintenance and had a fine feel. But a small diaphragm clutch is much lighter. To me, the motocross bike looks better suited to its intended purpose. And, like the Stark Varg, the MX bike has no gearbox.

I knew I had seen something like that before, and kept thinking antique board-track racer (which was not right). You can clearly see from the photo it's just a cut-and-welded standard bar -- not even a custom bend.

I downloaded a large version of the JPG. You can clearly see a gear-change lever!

When a DC motor starts, it draws several times its normal running current for a fraction of a second. What's worse, frequent starts or constant running? Depends on the duty-cycle I suppose. Either way, I would not lose sleep over it. The thing that kills fan motors is hitting them with a blast from a pressure washer. If only there were some type of automatic control to turn the fan on and off... 😛

It depends a lot on the ambient temperature and the condition of the cooling system. I would not worry about wearing out the fan motor. A more important issue is over-cooling the engine. Generally, competition 2Ts are run as cold as possible to improve charge density and maximize horsepower. But trials bikes rarely need maximum power. A more important consideration is improved charge vaporization (best throttle response) and a warmer intake charge helps that.

You should perform a pressure/vacuum test. There are many instructional videos on the topic on YouTube. This is the shortest and will show you the basic concepts: https://www.youtube.com/watch?v=kUmeyVcnZrs

I agree with lineway. Have you examined where the idle screw contacts the slide? Wear on the slide will cause difficulty setting the idle speed. But brass slides are less susceptible to that trouble than aluminum slides.

It's easy to try the encoder re-calibration process described here: https://www.electricmotiontech.com/home/em-epure-race/motor#h.aqwdzouw61q4 It's possible the throttle signal is out of range. You can try unplugging the throttle, cycling the battery on/off and then reconnecting the throttle. A crash can also pull on the handlebar wiring and cause trouble. It's best to have some slack in the wiring to the handlebars. Check for poor contact at all the connectors. Failing that, it will take someone with electronics knowledge and a multimeter.

You need to explain the problem in more detail. Do you have the optional regen lever (EM calls it PRB-R)? Are any tones emitted by the motor when you press the map button? Note that the controller will not permit the motor to run if there is a fault with the throttle. You can find the wiring diagram here: https://www.electricmotiontech.com/home/em-epure-race/wiring-diagram