OSSA

Wasn't happy with two red buttons on my bars.All better now.

I'm getting an ' Drive Circuit Open' error P1611 Everything seems to work Anyone know what circuit t It referrs to?

Hi all, I have a 72 ossa mar mark1, in 2017 I acquired the bike, I renewed the gear oil and from that point onwards my clutch sticks,when cold and to re-release it I need to rock the bike back and forward,my question is what is the correct oil I should be using for the gearbox/clutch, thank you for your response in advance, Ed

Just added a section to my website on identifying model years based on VIN and motor number. See it here: https://www.ossa-efi.com/home/factory-documentation/model-year-identification I would love to gather more examples, and possibly even create a registry of where bikes are roughly located. If you don't want to share your complete VIN, even the 10th character would be helpful. Likewise for the motor number, the two characters after the "I" would be helpful. I'm especially interested in finding examples from 2015. Feel free to contact me by PM.

I am so grateful for the help I received with my gearbox I want to give something back to this forum. I'm a retired electrical engineer and a hobbyist machinist. I have done a fair amount of work reverse-engineering the TR280i's electrical system. Cheers. I have replaced the .PDF file with an entire website: https://www.ossa-efi.com/home It corrects some errors and omissions as well as providing greatly increased technical content.

My 250 almost always requires 2 kicks. If I stop and immediately restart, 1 kick will usually do. But if it's stopped long enough to walk a section, it will probably require 2 kicks to restart. One the other hand, if the bike has been sitting for months it may start on a single kick. My 280 is somewhat more recalcitrant. It probably takes an average of 2.5 kicks. I have some theories as to why this might be so, but I'm wondering if others have managed to make theirs a 1-kick starter. This really doesn't matter during practice or if ridden as a trail bike, but during a competition it saps my limited energy. Both bikes have Easy-Start kits. I'm a bit of a l…

If this topic has been discussed elsewhere, I could not find it. I'm curious how many bikes (and of what type) were actually produced. If the numbers are unknown, maybe we can estimate them from VINs? I think my 2011 280 was a very early arrival in the US. Its VIN ends in 165. Same with my 2014 250, its VIN ends in 35.

What are others seeing as a 'up to full temp' coolant temperature in the software? I never really noticed before, but I was getting some off idle 'burbling' I've never gotten (except when the TPS needs setting) and thought perhaps it was goofed up. I saw 130C - fan would come on and go off, no boiling or any other issues. I didn't measure the actual coolant temp in the radiator, but it certainly seemed normal. Does it really run that hot? (I have not found anything in the manuals that state running temp yet) Mark

Dang, heck if I Remember the trick I used when I removed the engine. I remember thinking ‘I need to remember how I pulled this out’. Yeah, sure. I recall it is sort of partly sideways, but I can’t remember if the front part or the back part clears the mounts first. It is pretty tight. Anyone that has done it remember?

Just made this today out of a couple of bits of ally bar and an old bike stand I had around for when I finally get round to rebuilding engine.

Looking towards the winter, as the MAR has a bit of a false neutral thing going on: Who in the UK is the expert at engine teardown and re-build? Can deal with most of it but bit daunted by the shimming of gears etc as above. Thanks

Albert Juvanteny gives an interesting and very honest first hand insight into the Ossa company. He later rode Montesa , Mecatecno and Portus . After riding , he was minder for Gallach and developed the Alfer and JP motorcycles + more. - Visit his home - his photos, his memories and work now - Interview link below on my hobby web www.retrotrials.com/1-exclusive-intervie...lbert-juvanteny.html Photo Iain Lawrie

My TR280i came with those short custom made levers installed by the previous owner: I really like the feel on them and after also doing some research those are very custom made levers made by Finnish premium manufacturer, you can't even buy them anywhere (special order only). Aside from very good feel what I really like about them is they don't pressure all of my fingers like the normal long levers do (and especially annoying and loss of feel when the lever messing with my wedding ring, but with those Take-Pajas are perfectly designed for 1 or 2 finger use without touching the third or forth when pushed down) But makes me a…

Other than the tank and seat, what is the difference between an Explorer and an MAR please (I'm thinking '75/76 here)? I fancy having a go at long distance trials and don't want to mess with my current MAR so am looking for another bike, but Explorers are rare, so it may be easier to modify an MAR if it's just bolt on parts, then I can always undo it to keep the purists (me!) happy. I've been toying with a new machine but nothing inspires me - CCM SR-40 - expensive, fragile(?), Beta Alp 4.0 - heavy, little ground clearance, Kawasaki KLX250 - a bit lightweight? I don't want an enduro style machine so have ruled out everything else, hence thinking back to an Ossa... Mike

Me again ;-) Sorry for all of the questions! The gas light is always on, but the tank is full...and I have gone through more gas than is just in the lower tank (2L I heard) and I haven't run out. Any ideas? BTW, the other lights work for blinkers and lights, so I don't think the bulb swapped position. I think there are only 3 bulbs (nothing in top right). I do see that there is a sensor in the bottom tank and appears to be connected to the correct light (green/black wire if I remember). Thanks!

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…

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 …

It tore when removing it...I super-glued it, seems to be (barely) holding...but wondering if there are any replacements to get... Thanks

2015 Explorer. I’ve seen several Explorers that had the rear fender mount areas broken- there the huge handrail is mounted. I take those off anyway, since they get in the way when getting weight wayback. So I designed some bushings that will fill the broken sections and press against good part of the fender. This allows easy firm mounting of fender without grabrail, especially if the parts are broken.

Hi, I've just registered on the site. I have been replacing the fuel pump on my TR 280i and found a few helpful posts here. I was wondering if anyone knows where i can find an Explorer conversion kit. By the way I found the fuel pumps from the KTM 690 Duke's look identical and are relatively cheaper..