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tsiklonaut

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Everything posted by tsiklonaut

  1. Be sure the pin-locked crank bearing was fixed correctly (pin screw to the bearing's groove). If the pin doesn't hold it, once the engine heats up and metal expands the crank can drift w/o mechanical lock with pin - thus with a "drifting" crankshaft some of the crank sides (magneto or other side) can contact the crankcase at the extremes.
  2. It's a decent advice, will definitely do it more often to keep them lubed and fresh. I reckon it depends how much you ride in dirt and water, or in very hot conditions, that'd shorten the required relubing interval dramatically.
  3. Thanks for the info. Got the Allballs kit. The slack is quite noticable. Started to work on it, visually the linkage looks allright: In the end took me couple of hours actually, since they were like crap so I did it properly. See how bad they looked inside - completely dry and done: Cleaned and relubed the swingarm bearings as well, they were allright, smooth and tight, with no slack what so ever: The dog bone has gotten a little bump so the bearings didn't come out and went in that easy. Got to work it, but the bearing to bushing was a bit tighter compared to others so I probably have to get a new dog bone someday. The final collection of old bearings and bushings give a good indication how bad they were: After installing the new bearings and bushings I noticed the bike immediately is transformed. Rear end is sharp and bouncy, I now have to reduce rebound quite a bit since it was adjusted to that bad linkage movement. My rear end now flyes up considerably easier on rear-end lifted turns and takes landing from jumps considerably smoother. As I said, the bike really transformed. Hence this work was long overdue and I am glad I did it. Hence if you have similar slack - you ought to check the linkage.
  4. I made the spiked tyres myself. I bought some screw-in stud/spike kit some years ago, can't remember where I bought it but just using an electric drill with correct size socket and screwed them in the trials rubber knobs, with a pattern as I see fit. (To every knob maybe a bit overkill unless you're on ice all the time). If you get the screw-in type spykes, be careful with front tyre though since they tend to come through a bit and can puncture front innter tube. I put couple of rounds of duct tape on the inside of the front tyre to fix this, so those few spikes that penetrate the tyre stick into tape first before damaging inner tube. Beware trials tyres are soft, hence don't push or stop the bike too agressively on hard surfaces - or you'll lose lots of those studs . But on ice and snow you can quite push it no problem.
  5. Bought a nice s/h 2016 4RT Repsol. One thing I noticed there's a bit slack in the rear likage, so I reckon I need to replace those bearings to make it tight and smooth again. Anyone done it, any pointers what replacement parts to order, Allballs kit?
  6. Very nice Beta there, they are built strong like bricks! I've also found winter's nice riding, but with a lightweight bike like the radical OSSA (TR280i in my case). Superb overall bike design for it - no radiator in front to damage or clog up, no hot exhaust pipe to burn you up when you fall down and get stuck under the bike - can happen a lot more in icy and snowy conditions. For summer I use "sharper" maps then for winter I loaded "softer" EFI maps into OSSA brain so with those it tracks very well on snow and ice, with the correct mapping it gives superb traction in the slippery stuff in fact. Pics from previous winters:
  7. Big thanks Konrad, It's a great research and info! Will save the doc for sure. Interesting about the idle vs starting ease. I've found when I set the idle around 1450-1500rpm I gets a bit easier start. Adjusting idle isn't so hard when you have the diagnostic plug to compensate & reset the TPS when you open up the butterfly a little for more rpms. Still, air bypass sounds like a great idea.
  8. 2-5 kicks on cold start, 3-4 average. Mostly 1 kick with warm engine, sometimes 2 when I don't give sharp enough kick in some tricky balancing place. I have the 2013 TR280i wich is the super-high compression engine (even more compression than the red OSSA racing head sold separately so mine is VERY hard to kick!) and I don't have any batterypack start assist anymore, found it helped just a little but created lots of fuss with wires and battery weight. I've found those factors to look for on easier start that makes the start assist battery pack not a requirement: -correct TPS voltage and a bit higher idle (and I've tuned 50-100rpm higher than OSSA manual recommends) -it's important to keep the stator side chamber very clean (so it generates a good voltage, good practice is to pull off the magneto time-to-time and clean the inners) -a flywheel weight I have helps on starting too -on cold 1st and often 2nd kick are to get the capacitor full (it steals all the voltage then, so don't waste your energy too much on first kicks hoping it makes it better but actually it doesn't help much, I give 60-70% of my kicking power just to get some voltage into capacitor first), then on 3nd or 4rd kick the capacitor fires the volts out and starts on nice sharp kick (when warm the capacitor is full anyways, so 1st kick start most of the time)
  9. I'm on holidays for 3 weeks so can't UL for you now. But for future helps, since there's no OSSA support anymore, I or anybody else who has it here should U/L the software somewhere for those who need it? The software is required to set the TPS which should be done at least once a season to keep your TR-i in perfectly tuned running condition IMHO
  10. I also use the flywheel weight - really like it. I've had the same problem before, very easy to fix when you have the diagnostics plug. You need to re-set the idle via adjusting the throttle body butterfly opening. Ideally clean TB before too (there's an air hole in the butterfly that can get clogged with oil in time and the idle drops), but not mandatory since you can adjust it with TB butterfly opening anyway. The problem is when you change the idle you need to set the TPS zero point to 0.6V again so the EFI has the correct zero point for the smooth mapping translation. Do you have the diagnostic plug and software?
  11. tsiklonaut

    a smoky TR280i

    I just fitted as it was. Now thinking about it I think that way it's more correct: 1) there will be some pressure from the oil pouring in from the channels, fitting the spring side away from oil will cause a leak sooner or later (I've made this mistake on forks, they leak every time you do this!) 2) when installing the "other way round" you'll likely damage the seal on installing it (kicking it in from the spring side is a bad idea!)
  12. tsiklonaut

    a smoky TR280i

    A good mate of mine made it, he's a technical wizard and even better trials rider. It's a finely machined and welded semi circle, that just fits the three alternator bolts inside (remove the alternator, stick the same bare bolts back inside, turn the semi circle around them and just pull the cover off, easy as that!), even made a spacer support that centers on the crank hole so it has a surface to rotate on. It's a top quality handwork, even the expensive pro grade tools have hard time to catch that kind of quality
  13. tsiklonaut

    a smoky TR280i

    Could be, or could be the bearing is loose to strip a lip off the seal. The particular needle bearing gets its oiling from a separate channel (coming from two small holes you see below the big seal below the last pic) and it was well oiled as you could tell from the leak, lol. Those two o-rings both sides of the bearing are only to stop oil from getting into crank or magneto chamber, so the bearing gets it's oil anyway and you cannot block them with those o-rings, so the question is if it leaks into a place where it doesn't belong which was my case of leaking into crank chamber.
  14. tsiklonaut

    a smoky TR280i

    Opened the LHS case and a gulp of confirmed gearbox oil came out whre it's not supposed to be. Also found some suspicious rubber strips, apparently peeled off from the seal so I think I've found the devil - a failed O-ring. Replaced with high quality high-pressure seal (made for hydraulic pumps). Lets see if it last longer. After a longer run to clear residual oil from the exhaust - not smoking anymore, and now runs so sweet!
  15. tsiklonaut

    a smoky TR280i

    Cheers guys, some good tips on making a simple specialised plate removal tool. I'll seek into that once I'm there...
  16. tsiklonaut

    a smoky TR280i

    I checked the LHS hasn't leaked into magneto chamber, but I remember there was an oiling channel for the LHS crank needle bearing when I did an overhaul last winter, so in theory it could leak from the oiling channel into crank chamber as explained by you w/o leaking into magneto chamber at the same time (leaks only to one side). I guess I have to pull the LHS crank plate off to observe? Can't remember how I did it last time, but I remember it was a PITA to get it off w/o special tools. Any good tips on removing the LHS crank plate? Can't tell from the oil consumption since it tends to vary on mine (thick transmission oil get's stuck on gears etc). Will see if I can remove the crank plate, let me know if anyone has a good trick how to pull it with normal tools!
  17. tsiklonaut

    a smoky TR280i

    TPS was spot-on 600 mV, also no oil in magneto chamber. Wonder if it's the other side of the crank seal? If so then I'm fecked since it needs complete crank removal to get there...
  18. tsiklonaut

    a smoky TR280i

    Cheers guys for the great info! Will check the TPS first, if OK then see if there's oil in the magneto side of the crank when I have time on the weekend. OSSA people the best!
  19. tsiklonaut

    a smoky TR280i

    My 2013 TR280i has started to smoke recently, any idea what might be the cause? Doesn't run so well as well and it doesn't seem to be the fuel mixture issue, I've tried with a different fresh fuel/oil mixture and still the same. I figure it's maybe a gearbox oil leaking slowly into crankcase room, but where that leak might occur, a bad crakshaft seal in one side? Any ideas?
  20. Sherco/Scorpa is still a "classic" design 2-smoker trials motor. They recently switched to GasGas-type clutch (before they had somewhat unique clutch, but GG clutch is known to be among the best in "trials-feel", Ossa used this type of clutch since the beginning). There's no revolutionary designs on trials market anymore after OSSA went bust, I think Vertigo comes the closest in terms of revolution, but is still fundamentally a very classic design. I think OSSA scared the other manufacturers off with the experiment-and-revolutionize example - it creates high R&D costs and can make you go bust. OSSA is a highly unique and revolutionary motor, not just the near perfect Centre-of-Gravity (CoG) layout, thermal efficiency and FI but it's also smooth & superlight (I weighted an older Sherco motor and it was a pig-heavy lump compared to OSSA). OSSA motor definitely had the most potential if they had continued developing it. A well mapped injection is far superior to a well tuned carb IMHO. Ditto the cassette type gearbox - it's a dream easy to work on compared to other engines where you have to split the complete engine every time and while ironically the OSSA motor is also lighter (people used to say cassette-types are heavier). The frame is also unique because to fit this engine - fuel tank is a part of the front frame (no radiator exposed to rocks from the front wheel, hence a very clever design). Exhaust fills the rear subframe support function, both front and rear frame supports giving a better CoG compared to a classic full-frame design. The moving parts - suspension, wheels, handlebar etc are all standard parts. Also piston, rings and main bearings (after 2014 model) are actually GG parts. Hence most moving and consumable parts are no problem to obtain.
  21. I just recently put S3 standard (A) into B bore. I have the very high compression (2013) head and also mine tends to run hot often so it's a good choice to avoid seizure and give the engine more "relaxed" operation (less friction) when hot. Just check if you see honing marks on the bore (the around 45-degree oval lines) in the working space of piston, if you see those clearly in reflection and you see no excessively worn spots then you're fine without doing re-boring/re-coating, just put in a new piston with rings.
  22. Headlight is just fixed with two clips. Just take easy on them and in warmer temperature, so the plastic doesn't snap easily. Headlight and it's wiring is a complete chinash*it (read cheap and fragile), I've broken the wires many times and they self-destruct in time anyway. In the end I just binned it and the dead headlight stays in place just as a design element, rear I just removed, LOL.
  23. My TR280i has well over 300 hours, so had my trusty '13 for some well deserved refreshment, made it more minimal and elegant looks, more OSSA style:
  24. Yep, check the master cylinder as well and try to replace the piston (the seal lips wear vs the new ones will give you a good indication). If the pack thickness is correct then it just doesn't hydraulically push clutch enough to engage fully. Removing all air from the hydraulic system is vital of course.
  25. On a second thought quite sure it's the master cylinder plunger seal. I had the same symtoms once. Those AJP seals wear fast, I always buy multiple to keep as spares.
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