tsiklonaut

I would NOT call carb reliable nor simple. I've had 4 carbed bikes and they've created me about 10X more problems than the 3 EFI bikes I've had. With EFI motorcycles I've ridden around 300 000 kilometers, visited all continents (except Antarctica), over 80 countries, from -200 meters (Dead Sea) to 5360 meters (Himalaya passes in India) above sealevel, from -25C to +45C deserts - and I've needed to touch nothing, I mean NOTHING, literally! OSSA included. It has run like a dream all the time during many years of excemplary service (and mostly that's an old BMW GS that is considered very unreliable by any Jap bike user btw). While with my (commonly known as super-duper "reliable" Japanese!) carbed bikes I've had constant hassles with wrong or annoyingly changing mixtures, clogged channelways, worn parts, leaks & smells. Even my wife's Suzuki DRZ 400 gives me constant annoyances and my hands often smell of fuel fiddling with it. Carb has way too many parts (vacuum pistons, springs, many screws, jets, needles, pressure rubbers, floating elements, bearings etc etc) that can wear out or go wrong, it has an airflow and channelways intertia, is very suspect to flow turbulances as you play with the throttle - hence it's very hard to control & too often unpredictable, let alone to make it simple. Due to unability to make it simple to make it work as predictable by a human rider as they can a modern carb is actually made very complex compared to modern EFI, most modern carbs have at least over 30 different parts, better carbs around 60 parts, over half of them that can go wrong. EFI only has a ECU, TB, temperature & pressure sensor, fuel pump, pressure regulator & injector. That's it - some 7-8 parts that can go wrong. Through experience I'd consider myself a testamony to EFI simplicity and reliability vs carb. The only "complexity" on EFI is mapping it for the speciefic engine and the intented use. So in the beginning that takes a lot of time, a lot of measurments, experience and experimentation by the manufacturer R&D team (and the very reason most trials manufacturers haven't dared to step into EFI territory) but once you nail it then you're done forever and no carb can compete with it. Hence EFI is superior whatever the application it is deseigned for when done right. OSSA has made it superior particulary for low-mid rpms - mostly for traction and the engine be fully predictable by the rider on their TRi models. Have you ridden an EFI OSSA? To my surprise OSSA is actually surprisingly weak & mild on flat-out RPMs, there's no mad uncontrollable power like some bigger bore GasGas at full throttle. The payoff is OSSAs superb control on RPMs you mostly use in trials, the lows & mids. I mean with the right mapping (soft or hard surface speciefic) it's exeecingly hard to make rear wheel slip with OSSA, it just grips. You give throttle it comes as you expect to depending on opening, you shut it out it immediately shuts it as you can fully predict, there are no ifs or buts. With carb there's always some lag due to intertias of so many different parts, some residual mixture leakages or bypass flows and it's much more suspectible of flow turbulances than a well mapped EFI, making carb considerably more unpredictable by the rider in comparison. Hence the goal is not making peak power or peak performance as you say, but making it more controllable & predictable by rider to RPM ranges most used. That's where they OSSA made EFI superior to a carb - in trials application in this case, IMHO at least.

Ditto as Lotus54 said. It needs 9-12 volt power before ECU starts communicating over USB. The kit I have has 12V adaper to plug into capacitor circuitry, you have to disconnect the cap then connect the 12V cable. You will hear fuel pump fire up when connecting. After ECU stars comming all the graphs, info & diagnostics go live in K-scan software. Good test to see If ECU is responding is to choose ECU info, if theres no data then no ECU response, if serial number etc presented then OK and all works.

Do you have any maps? If you don't have any I may send you some, be sure to let me know your ECU version, if it's ECU17 (early OSSAs) or ECU19 (later OSSAs), I have a lot of different maps for #19 version, some for #17 version too. Maps I load with the loader programs. K-Scan program I use to reset TPS (Throttle Setting), idle speed adjustment (using tachometer), reset the 3 hour counters, different graphs etc maybe also use the leanin/riching function someday, haven't experimented with this yet myself.

Love my OSSA TR280i more every day. Today had a decent dash in the forest:

Mark's offered me cheaper than most aftermarket bashplates, hence I grabed it. He made around 10 of them, I think he has some 6-7 left. If you're interested it's best to PM him I reckon.

Anyone else a bit dissapointed in the stock narrow and short bashplate? I think OSSA made it too small to save weight. My bike has seen a lot of riding abuse and I found mine has very much worn out a great deal of footpeg lower parts and frame, some serious dents on the suspension linkage too: Plus also I put on a flywheel weight that made my gear lever stick further out w/o protection, hence decided to get a wider and longer bash plate. Thankfully Mark (jkmr1) in this forum has made a laser-cut wider bashplate speciefically for OSSA for a very decent price and sent me one from OZ. Here's vs stock: And now covers up the exposed areas very good, hard to see on the pic but being around it also provides better protection for the linkage: As you can see the gear lever is now protected too (the moving tip is only exposed that move away when you hit the rocks) Another good feature got a nice OSSA logo laser-cut inside too, so when you wheelie everybody will know the special bike you're riding LOL

Good on you, now you owe me a beer mate

Yes, but specialized parts aren't marked there. You must e-mail to Joa and ask if you require any OSSA parts.

Got from Joa Hindren. He's official OSSA, Scorpa & Vertigo dealer in Northern Europe. Joa is a very knowlegable person about OSSAs and I've got everything I've ever required from him.

It's proven many times over that a well designed and mapped FI is superior to any fiddly carb in existance (ask ANY high-end race machine designer or race mechanic (only a village mechanic will tell you carb is superior)). Why the other manufacturers dont use it is a simple case of experience. They have none. FI needs a lot of work at the beginning to get things right for the speciefic engine, most manufacturers just dont have the balls to make a move from that smelly carb they are too used to and it does work satisfactory for them. With FI you can make it work brilliant. True, OSSAs FI isn't perfect either (a system w/o battery do doubt will have starting issues), but TRi is known to be the smoothest pulling and most predictable 2T trials bike engine currently around. Its not because reverse cylinder, its because they have invested a lot of time making a well mapped FI for it.

I'm happy with the cables made by the OSSA EFI designers themselves (has also the 6-pin connector for the newest OSSA models): Also got a big library of different maps from my dealer on original OSSA branded USB stick You can do lots of things with this kit, from EFI map loading to TPS reset to diagnostics of different parts to a very handy work-hours count (one count is overall since the bike is new, the other two counters you can reset yourself so you can keep a service record for different parts). Idle speed, intentional mixture leaning or riching etc etc. Loads of detailed reports and adjustments you can't even imagine possible doing on a carburated bike. OSSA's really pushed the 2T evolution frontiers with this ingenious design.

Yes, they seem to be harder to get now. I got mine recently, but maybe it was a lucky shot - my dealer said it's even better than the original cable, but harder to get. OSSAs original cable cost rediculous 900+ EUR so it's pointless unless you run some (impossible) high-profit dealership. Third-party manufacturer Btwice did some medium-range cables, maybe some luck from there?

Yes, would be very sad moment if such a great trials bike concept will go away from the market. No-one else has had balls to go that radically fresh minded approach and out-of-the-box in trials bike design recently, all others just slowly push on the classic design. Some say OSSA did try to get Bou, but weren't able to afford such a high-calibre rider as a very small manufacturer themselves. No doubt they'd dominated the scene if they'd have a true top rider riding their very capable bike with full factory tech backing. Actually the cables are very resonably priced if you get the non-OSSA cables. I got the cables from the guys who designed the OSSA EFI system (Kokusan Denki manufactured it), it was very cheap from them (120 EUR or so if I remember). Works superb and very easy to use, I just loaded the new EVO6 map for the Termignoni exhaust setup I installed, will try it when the snow melts away LOL. I've inspected it a lot and I would dare to say the OSSA EFI system is superbly well designed and made (in Japan) IMHO.

Tyre pressures are always academical. With trials bike they are much more lower than this, but Explorer isn't really a strictly trials bike, it's more of a trail bike, hence heavier, ment for sitting on and thus requires higher tyre pressures to avoid punctures. Suspension set up according to your individual needs. Set the sag 30% of the suspension travel. Meaning when you're on the bike it should fall 6-8 centimeters from the longest position (i.e. bike on a center-stand). You do not need a special key, any c-spanner will do adjusting the rear shock spring preload. Once the correct sag is set for your weight then start setting dampening and rebound - this is very individual according to your riding style and conditions. Adjust as you daily ride, but once getting close to near ideal-range dont go more than 1-2 clicks from one or other direction. 2012 clutch probably isn't the best "feel" of OSSAs since they've upgraded the clutch almost every model release. Later clutches being noticably better than the first models I've heard, my 2013 is fine as far as I can tell, very good and light feel. If it's too annoying buy a new complete clutch, but remember it requires some skill to set the thickness exacly right and to correctly adjust it. Hope this helps.

Sounds interesting. Inspecting the butterfly motion in TB it does visually look like the 15-deg opens the aperture more "progressively" vs the stock 5-deg. The latter is probably more mild and predictable. Looks like 15-deg is a good mod when you need more rapid "pop" from the engine. I'll see into mapping compatibility once I get there and have an actual need for it I reckon.

Big thanks Peter, that's a very good info! Makes sense too. Sure the 125 requires more to be sqeezed out from the small motor. 280 is already very nicely balanced in the power and delivery department. I guess 15-deg butterfly is a good upgrade when one would require more progressive power out of this engine. Other interest is a very high altitude (3000 + meters) behavour, this TB mod may acctually be beneficial there with the right maping. I'll experiment with it when I have more time. Cheers, Margus

My OSSA dealer gave me both stock 5-degree and an "experimental" 15-degree butterfly along with Btwice throttle body. Looks really interesting: 15-degree butterfly is oval with angled edges and thus starts from more off-angle position and regulates the air flow in a more "progressive" fashion vs stock. I wonder with TPS having larger starting angle yet the engine gets less air (= theorethically richer mixture on low-rpms as it gets more rapidly leaner when opening up the throttle) if it improves bottom end delivery as well? Anyone has Btwice throttle body and experimented with a 15 degree butterfly? Is it worth experimenting with different custom EFI maps or it required designing my own custom map for it? I have the diagnostics kit from people who designed the OSSA EFI with lots of different mappings, so maybe should go through some of those first I guess.

Yeah, but unlike 4x4s there's nothing that needs to run in oil. When a little water gets inside it'll come out via that small aperture on the bottom and as said before spraying things with some sprayable oil will prevent corrosion. There's very little to worry about, just ride the damn thing Actually, on a second thought, when you also found some oil in there - maybe it's part of OSSA design then to intentionally let in some little oil into magneto box to prevent corrosion? I.e. I know BMW uses special o-rings between shaf-drive dry/wet compartments that let through some oil to lubricate parts on the other side a little too (annoys some owners, but it's actually part of the function lol) Flywheel puller is 27 mm normal right-hand thread (not as some people say that stuff on the right hand of the crankshaft are left-handed thread). Don't know the pitch, but looks pretty standard to me (1.0?). I have the Jitsie puller (for GasGas), works perfect on OSSA TRi flywheel. Found even a cheaper alternative here.

Ian, When installing the flywheel weight I discovered mine leaked a little motor oil into magneto box. After removing the flywheel turns out one of the holes fixing the magneto-side and thus sealing the motor oil is differently placed (it's "out of sync" against crankcase bolt holes), I simply can't fix one of the bolts (maybe my 280 has some fancy magnesium crank case that was engineered a little different?), thus it little leaked from this one place. I just plugged it with a smaller bolt and lots of locktite glue, now it holds the magneto case dry. My verdict on the flywheel weight: I really-really started to like it. The difference is subtle at first, but the more I practice the better I manage and think it's made a better handling bike and a better rider out of me. Traction is better and more managable almost in every situation. To sound very stupid I'd say before it was like "Raga" stylistic handling bike - rough, fast and sharp but get everything done when your very skillful, with flywheel weight it's more like "Bou" style - smooth & perfectionist, it forgives more misjudgings and mistakes and is more predictable. Hard to describe really,you must try it if you like it or not. Although the diffrence isn't as big as I may make it sound beware it still needs some few riding days of trial-error testing to fully adapt to changes, your throttle and clutch usage habits will become slightly different. I'm still learning and let's see how I progress, but as said I feel in my case it has improved many aspects of my riding,

I have a very small cutout from the lip below the cover (looks like straight from the factory, on my 2013 model cover). Just around a millimeter or less, when cover closed leaving a very tiny hole - just to let out the little oil residue from the bottotm or to equalize the pressure differences with heat expansion or cold contraction. Also when doing very deep fording (engine half-submerged) the water can't get in since the tiny hole on the bottom and the equalized air pressure keeps the water out. Thus I see no point for additional weight with a top-mounted breather with a house - too much additional weight, bits & added complications, IMHO at least. Just make a narrow cut with a thin saw or a knife below on lip of the cover and you're done.

Makes sense since it's so simple and elegant way to save weight and sure some engineer must have that idea already in the past. Britten V1000 from early 1990s is a good way for engineers to approach the frame design - a motorcycle doesn't actually need a frame when designed correctly - crancase, fuel tank and exhaust all can do this function. OSSA also uses a lightweight aluminium fuel tank as part of the main frame superstructure (and also the radiator is protected from dirt and rocks behind it), I wonder if anybody else does this smart design trick on a trials bike? I know Sherco is using it as a part of the rear frame support.

It's not a problem, just a visual annoyance. There's no oil in this side so there's absolutely no need for perfect sealing. Probably just not seated correctly. I'd take it off and see if the lip is damaged on the plastic (black) cover. Maybe need to straighten the lip with a sharper knife or a screwdriver to make it fit again. When correctly seated the plastic cover should fit without a gap even without the bolts applying the pressure.

Did you warm up the engine? Bottom end warms up when the ventilator starts to run + some additional 5-10 min when the cylinder heats up the bottom crankcase oil where the clutch plates run in. Mine drags cold too, but after warmup there is almost no drag at all. And forgot to add one important thing: it drags a little on very cold weather even when warm. I think maybe running a thinner oil for cold weather?

Good to know there's some serious hope. I hope they pull it through. OSSA has a small but a very passionate following. They sure have a client base and people interested in their bike, personally I might be in the lookout for a brand new 2016/2017 Factory R actually if it comes. I think they could fill in a niche in trials market, smaller scale but a higher-tec R&D and production to push on the trials technology envelope and think outside the box. Also beneficial for other producers to copy their innovative ideas (i.e. Vertigo 2-smokers also have EFI now, and others starting to use the exhaust as a rear subframe etc).