OSSA

Hi, Thinking of fitting a PWK 28mm on the old Gripper. A common mod by all accounts, however I’m struggling to find the basic start jetting for these carbs. Does anyone know and willing to share? I have an 28mm OKO already but I guess it’ll need jets/ slide/ needle to suit the gripper. TIA Brent

Looking to paint my Ossa 280 frame and swingarm green.. Have seen the latest 2013 model is green and it looks great. Has anyone any suggestions as to what paint to use..... 2pack, Cellulose, etcetc... Thanks

I have purchased a bike listed as an OSSA MAR 250 1975 Documents confirm this. Engine number also correct - M222.... However, frame number is B241... which appears to be for a MAR 350. Any thoughts ??

I recently acquired a Pluma/Plonker that came from a high elevation. I live at about 1,000 ft. elevation above sea level and the bike runs too lean. The bike has a 24mm IRZ carb and I want to keep this carb on the bike. I know finding IRZ jets isn't very easy and I want to limit the number of jets I purchase. Does anyone know what jet sizes and needle clip position this carb came with or should have for a lower elevation? Currently, the carb has a 45 pilot and a 101 main jet. I could guess and get a 50 pilot and a 110 main, but like I said, would be nice to know more specifically without all the trial and error.

Just bought a 2014 TR280i with an explorer conversion kit 1) how do you connect the explorer tank to fuel system 2) does anyone have the part number for the easy start system as the one supplied doesn’t look correct ? thanks

That's the rumor from a spanish guy at the thumpertalk trials forum. Says he got that from the local newspaper. http://www.thumpertalk.com/forum/showpost....mp;postcount=53 Pretty big news if true.

Hello, I would like to know if there were OSSA MARs (MK1) with a four (4) speed transmission? I live in the USA, so I don't know if some 4 speeds were ever imported. What engine number sequence would I be looing for (M-344 XXX)? You don't have to tell me the best way to find out is to ride the bike....Lol...I would, but the bike is 2,000 miles away. The seller claims it is a 4 speed, but I have my doubts/want to confirm. I thought all MARs were 5 speeds. I appreciate any information.

Hi Guys What are the torque settings for the rear sprocket on a 1976 OSSA MAR?

does anybody know where i can buy a new fuel fitting that threads into my carburetor? This bike’s a bar find so some parts are missing off of it. My bike is a 72’ OSSA 250 Mar

Hi, can anyone suggest somewhere to get a set of decals for my 1975 Mk2 mar? Apart from fleabay I can`t find them antwhere. Cheers, basketcase.

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

The bike is together, and now has a bit of ride time around the yard. No issues, and very pleased with it. When I went to buy spark plugs weeks ago, I thought I got the correct one. I searched the internet quickly and found recommendations from heat range 8 to 5. I read that BP6ES was correct, and it did cross reference to the ages old Champion N9YC I removed. I now suspect, having seen other references to BP7ES being correct. I have pretty much ruled out the heat range 5 and 8. So, for a 1973 MAR 250, is it a NGK BP6ES or BP7ES? Ready to get the jetting fully sorted out, and prefer to do it on the truly correct plug.

New to the Ossa but after 1 trial on it enjoying it so far. Fitted with a Mk2 Amal Concentric but seems rich on the bottom end. Anyone have recommended jetting or alternative carb recommendations?

As the title says, does anyone have their own mapping leads? Is so where did you get them, and does the purchase give you access to the latest maps and the update software? I enquired but there was a reluctance to sell them to non-dealers, Plus they are extremely expensive

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

OK are there any electronic/computer geeks out there who have an OSSA TR280? I tried to buy the cable from an ex distributor and they wanted $650CAD ($500USD) - no way. I cannot find one for sale in elsewhere. BTwice does not respond. If I know the proper communications protocol, a cable could be made up for under $40CAD, which would include the connectors to the OSSA. After hunting around I was able to find out some information: Two of the four pins on the diagnostic connector are for power. The other two are for communications. Looking at a picture of the BTWICE cable (from USB) it shows some electronics for protocol conversion, but I cannot quite…

I own 2014 Ossa explorer which I used it for difficult track trail riding. It has standard 10 tooth front sprocket. Do anybody know where I can get an 11 tooth front sprocket ?. Most mail order shop only stock 9 or 10 tooth. Or is it the same as some other bike brand ? Thanks

Hi All Im replacing the piston in my 2013 ossa tr280. I am having trouble finding an oem piston kit anywhere. I did notive that there is a s3 racing piston kit available - has anyone had any experience with this kit? I am also replacing the cylinder or perhaps sending the bore away for rechroming. Its about the same price either way- any thoughts? Thanks for your time Gene

Is there anything inherently bad with the 350 engine compared to a 250? I thought that I remembered reading that they were prone to running hot and if so is it a real problem?

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?