OSSA

Hi folks - Adrian again here with my basket case Ossa! So I went to put the clutch mechanism onto the shaft. Behind the clutch are a thrust washer and a spacer according to my Clymer manual. As always with a basket case like this - I don't have these parts, or if I do - I don't recognise them amongst boxes of irrelevant non-Ossa parts, machine tool bits and bobs, random stuff etc... I have a thrust washer that fits on the shaft nicely, but how thick should it be, and what about the outside diameter? I have no idea as to the size of the spacer, but I assume it is wide enough to ensure that the inner sleeve of the needle roller bearing is just proud of the clutc…

Hi all I'm restoring a TR77 that I was given as a box of bits (and so have no knowledge of set up...). My Clymer manual tells me that the Ossa has electronic ignition, although the points and condensor set-up on my bike suggest otherwise! I've fitted new points and condensor and now need to set the points gap and timing. The back plate has a clear timing mark that lines up with the crankcasings, so I set it at this position. I then set the points gap to 15 thou, and this opened the points at around 2.2mm BTDC. I searched the internet and found suggestions of anywhere between 2 and 3.5mm BTDC, and a points gap of 40 thou seemed a common theme. So, what works be…

Anyone knows if there's a high altitude (2000-2500 meters+) EFI map available for TRi?

This is a problem of my own making and ossa ignorance. I have recently had both the primary case and magneto cases off ; one to free off the clutch and the other to check the points. Whilst the case housing the magneto and gearbox sprocket was off I inadvertently leant the bike over onto its side and the clutch pin fell out which I found a few minutes later. Today when I went to rebuild the bike and sort out the clutch I remembered that the clutch from the engine lever to the cluch housing has a long pin, a ball bearing and then a second pin. I had lost the ball bearing. I had in stock some 1/4" cycle headstock bearings so I used one of them between the two pins. I could …

Recently acquired an Ossa TR77 - well used but sound. Been standing for about 5 years. Initially it had no spark but I tweaked the points and they started to show life. The bike is not a good starter so I have some new points and a new condensor to fit tomorrow. The spark is good but it is not bright blue - hoping the new points will fix it. Got it running yesterday but it would not rev and kept bogging and backfiring in the exhaust. After a while it was running of a fashion but with cloud s of blue smoke which I hope was just unburnt fuel. What is the best plug for this engine. Is it possible to fit the mar engine into a gripper frame. On the carb there is a large ai…

Hi Guru's, As I get older I am finding the effort involved starting my Ossa becoming a bit much for my knees, unless I can find a box or a bank to stand on I generally stand alongside and use my left leg and kick backwards like I did with old Bultacos... I have been considering investigating the current crop of 125's but since I really enjoy, make that love, the Ossa (once it's running) was wondering if anyone had ever shoved extra base gaskets in to reduce the compression making it easier to turn over. Note that I don't need it to start easier, it's not bad at that, but just to reduce the effort! I appreciate there will almost certainly be a loss of horsepower …

Ossa Explorer/TR280i: I have an order for one of these, but in the meantime, is there another brand that might fit (KTM, Yamaha, etc.)? Both of my bikes are broken, and am trying to get one ready for the 3 day weekend !!! Thanks!

I've gone to change my sprockets today and last time I Was in the ossa dealer I bought a set which was front 10 and rear 42 but I've noticed the front I currently have On is an 11, can anyone tell me what the standard set up Should be on a 2013 300 factory rep

Since there doesn't seem to be anymore rear mudguards or side panels anywhere around right now- I'm fabricating a once pice setup from aluminum. I've never done this sort of thing in aluminum (I have in fibreglass)- so,it is sort of a learning process. I made up a template, then cut the three pieces from aluminum sheet. Now I'm welding the side panels to the mudguard. They both use the two side screws by the end of the seat, and overlap. Might not be the best looking (at least this first try)- but I'm hoping will work well. My mudguard broke and I have it pieced together (plus a new spare, but don't want to waste it) The bike is just so darn fun- I sure hope th…

I have fitted a Mikuni VM26-8074 to my MK2 MAR this came with 190 main and 50 pilot I have now fitted a 150 main and 30 pilot and it is running ok but the throttle response at low to 1/4 throttle is still not right, as the main and pilot were to large I was wondering what the Air Jet size should be, the one fitted appears to be 0.5 but it is very hard to read

picked up a lightly used 12 280i. first ride 15 minutes in bike dies like i hit the kill button. now shows no sign of wanting to run. even 5th gear bump starts on a big hill. bikes seems to have spark but maybe intermittent? pull fuel line of injector and fuel pumping is pumping. very quickly regretting this purchase. anyone got any ideas on where to start looking?

In the diagnostic software there is a setting that allows an increase or decrease in the amount of fuel the bike uses. Anyone messed with this? What is the purpose? Default setting is of course 100 % but can be changed by +- 5%

Looking to replace just the pick up on bike as stator bolt sheared off and took out coil. need to know its output etc to try and replace, Thanks in Advance Krash

After that short statement maybe 3-4 months ago from ossa head honcho Joan gurt, nothing? Looks like all the doom Sayers were correct.....unless anyone knows different? Any news? Good or prob bad!!!

I have posted before about the tanks and I think I have them connected correct and with safety wire on the tubes between tanks. I filled the tanks slowly, bounced the bike around etc. On the trail, after about 5 miles, the low gas light comes on. I figure I better head back (slowly). It did seem to run out of gas and I would lean left/right and I even blew into the top tank to try and push gas lower. I was able to keep riding and made it back. I think the top tank is the bigger of the two...shouldn't that go more than 5 miles? Some complications: I was at maybe 6000 feet and the bike didn't run great. I don't think there is an idle adjustment. I doubt it ha…

Hi, just bought a 2011 tr280i and want to mount lights and ossa dash... Have the original ossa dash (trailtech vapor with ossa logo) with 4 wires coming out. Dash works with CR2032 battery. Dash shows actual RPM (through labeled tach lead) when bike is running Power lead does not seem to work (14 volt from bike / dash backlight should be brighter when running ?) Two leads have no label : A 2 wire plug (this is to speedo sensor ?) A 4 wire ( 2 pins in the middle assigned from dash ) this is temp sensor. From the OSSA bike comes a 4 wire connector with 1 pin assigned (brown cable). It measures between 5 and 1 volt (drops when temp rises) between brown…

This is probably like asking everyone about their opinion on oil, but what the heck ;-) I like my Explorer, but I have 2 concerns: 1) It might just be too complicated with my limited mechanical skills (and limited dealer support). See my post on fuel issues, engine mapping, etc. If it breaks I have to learn how to fix it and that won't be happening on the trail. 2) The official riding areas in my area are setup for dirt bikes, so a trials bike is mostly overkill. It has helped me on a few trouble spots that I can now ride on my dirt bike on, so I am very happy about that. These spots are usually scattered around the park, so not ideal. I am sure there are many …

Hi all; New here as I just bought my first trials bike, it is a 2013 Explorer set up in trials form with only a few tanks ran through it, so it has sat around and been ridden very little. After buying it I took it for a ride, had some clutch drag when it started, I road it up a fire road one mile to the trail head, as I proceeded up the trail a quarter mile the clutch faded to nothing, as in the bike sitting in gear idling. Back at the van I let it cool for five minutes then I had full clutch again, rode around the parking area and the clutch faded again. Back home I found the oil was over filled, so I drained it put fresh oil to the proper level. A few days later I wen…

Does anyone know if there any wiring looms about or of a wiring loom i could cut up and re solder ,spent 2 months now trying to fix my bike just about every thing has been changed other than wiring loom and ecu been in a shop and thought it had been fixed ran fine for 2 weeks now the problems back

Hi, got bad snatch when warm, Oil makes no difference. No luck trying to contact Steve Sell by any method (no I don't withhold my number) so: Anybody know if the In Motion kits are OK? Or any other pointers? Many thanks Nick