Jump to content

konrad

Members
  • Posts

    620
  • Joined

  • Last visited

Posts posted by konrad
 
 
  1. 2 hours ago, Tr1AL said:

    ...and AGIP OSO 46 in the LEFT SIDE whatever that is.

    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.

    • Like 1
  2. 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? 

     

  3. 8 hours ago, BC_Islander said:

     I have a fluke dc clamp meter if that helps...

    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.

     

  4. 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.)

    • Thanks 1
  5. 23 minutes ago, lemur said:

    I have the header pipe with the Cat converter and the O2 sensor from my 2014 260 4RT sitting in my spare parts box.  That was my only 4RT that came in the crate straight from Spain unopened.

    I stand corrected.  Should have kept out of it.

  6. 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.

    • Thanks 1
  7. 1 hour ago, miner said:

     Still getting a fair few kick backs when repeatedly kicking it…

    Thoughts?

     

    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.

     

     

    • Like 1
  8. 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.

    • Like 1
  9. 4 hours ago, mcman56 said:

    Maybe something along the lines of a Japanese flat track handlebar?

    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.

  10. 1 hour ago, thesaint said:

    I would think having the electric fan motor working all the time do wear the electric fan motor out faster compared to having the electric fan motor starting to work when the thermostat send signal for the fan motor to run or what do think?

    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.

    3 hours ago, lineaway said:

    Trouble with a switch, people forget about it.

    If only there were some type of automatic control to turn the fan on and off...  😛

    • Like 2
  11. 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.

     

    • Like 2
  12. 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.

  13. 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.

     

     

  14. There is a saying in electronics troubleshooting, "If you can't make it better, try making it worse.  You may learn something."  Based on your measurements, the finger height is nearly a millimeter out of spec.  I would correct that.

    I have found it difficult to measure the clutch pack thickness accurately.  A caliper is better than a micrometer for this job due to the increased surface area. 

    The variation in pack thickness is important on the OSSA.  Here is the procedure to check that: https://www.ossa-efi.com/home/my-upgrades/clutch-control-ring#h.twzu1hiimf5e

    The two good rides is a puzzler.  Did you soak the new friction plates in oil overnight prior to installation?  I find that helps maintain consistent operation.

    Finally, it's not something crazy like inadvertently mixing DOT fluid and mineral oil in the clutch hydraulic system is it?

  15. Good question.  It would not with a wire-wound spring.  But disc springs are not like wire-wound springs.  The finger height being wrong could also change the leverage ratio. 

    Are you sure have everything assembled correctly?  On the OSSA, the fingers have an inside surface and and outside surface.  The difference is subtle but noticeable.   You should be able to see which way there were installed originally by slight wear marks.

  16. I don't see why you couldn't re-weld it.  BUT... is the weld designed to be the weak link that fails thus preventing more costly damage elsewhere?

    I assume a crash on the gear-shift caused the weld to fail.

    Because OSSA gearboxes are so fragile, I machine a Nylon washer for the shift shaft that goes between the lever and the engine case. This prevents the shaft from being knocked inboard. No gearbox failures from crashing, but unsure if I have ever actually had occasion to test it.  

 
×
  • Create New...