trialsrfun Posted July 24, 2013 Report Share Posted July 24, 2013 (edited) Could you help identify which OSSA trials model this is please, frame number B-700~#~ engine number M-700~#~ I initially thought it to be a TR77 250cc but after a google search this model seems to start with a B-72 number designation. Also what is the correct colour, some TR77 models have a black frame & dark green tank, others an all over lighter green frame & tank. It has sloping down rear shocks, lower mounting at the rear end of the swing arm with the upper points a little way down the frame tubes. Full width hubs which as far as I know are the same as those on the MAR. Betor forks, gold anodised wheel rims, the exhaust pipe is longer than on a MAR, it goes down from the cylinder before turning back up and over the engine.Carb is Mikuni. Any other info would be useful such as shock length, ignition and carb settings etc. Edited December 24, 2013 by trialsrfun Quote Link to comment Share on other sites More sharing options...
woody Posted July 25, 2013 Report Share Posted July 25, 2013 Some of the frame/engine number sequences can't be found on the ID charts. My 350 MAR has matching frame/engine and starts 43 but it doesn't appear on the charts, it should begin 24 according to them. Same with the 700 sequence, it's not on any chart I've ever found. I had a bike with the same sequence. It definitely relates to the green MAR but whether it's the black frame or the all green bike I don't know. Mine appeared to be the all green model (it was in bits) and the gold wheels on yours suggest the same as the black frame bike had silver wheels as far as I know. Apart from the colour, they're the same bike really, which itself barely moved on from the earlier MAR. Same frame, different shock location, same engine, longer forks and points instead of electronic ignition. Timing between 2 and 3.5mm TDC. Carb should be an Amal on the 240 but don't know jetting. The shock length you should get off the Falcon Shocks website 1 Quote Link to comment Share on other sites More sharing options...
trialsrfun Posted July 25, 2013 Author Report Share Posted July 25, 2013 (edited) Thank you Woody for the info a couple more questions though if I may, should there be two engine to frame down tube bolts or one longer one with a spacer between, are the original bolts std metric thread or fine like on a Bultaco. The side panels are alloy but there is no spring or clip in the airbox to hold the foam between the two gauze panels what might be missing? Have yet to look in the hubs, do OSSA have steel brake liners or chrome on alloy surface again like Bultaco? Further checks have revealed, The ignition fitted is definitely electronic, no points. Looking through the crud inside the sump shield there is some light green paint so I would think this one was an all green model when new. Checked the Falcon site & shock length is 13.65" for all the OSSA trials models listed so 340mm length should suit. 340 millimetres = 13.3858268 inches. Edited July 25, 2013 by trialsrfun Quote Link to comment Share on other sites More sharing options...
woody Posted July 25, 2013 Report Share Posted July 25, 2013 The sump bolts were seperate bolts each side originally but I can't remember the thread pitch from when I had one back in the day. The bikes I have now have long since lost their original bolts. I just use standard 8mm bolts. Fit them so that the nuts are on the outside, that way, if you need to remove the sump you can just push the bolts through far enough to clear the bracket instead of having to to remove them completely. The sidepanels are fibreglass originally and new patterns are available. On the inside of the airbox cover is a straight bracket which is held by a rivet (from memory) There is a conical shaped spring that sits between the airbox cover and the gauze panel. The smaller end of the spring tucks in behind this bracket. When the sidepanel is attached and screwed onto the frame, it closes the airbox cover up and the spring holds the gauze sheets and filter in place. In Motion sell a new airbox but not sure if they have the spring. You may find a spring from USA suppliers if In Motion can't help. Hubs are normal steel liners It's possible Ossa may have reverted to electronic with the later green bikes, they definitely had with the Grippers. Or someone may have fitted electronic to replace the points. The same ignition fits all bikes so not an issue. Quote Link to comment Share on other sites More sharing options...
trialsrfun Posted July 26, 2013 Author Report Share Posted July 26, 2013 Cheers Woody you have been a great help Quote Link to comment Share on other sites More sharing options...
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