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ask greeves

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Everything posted by ask greeves
 
 
  1. What about the tensile strength...just as important ...
  2. A 200 forward kick Fantic swinging arm bearing, is a lot different from a 240....BEWARE
  3. Suggest you use a venier gauge and a means to convert mm to imperial.....1957 DMW sounds imperial sizes........Could be 1.25ins (32mm) and 1.75ins (45mm) maybe !
  4. Sounds to me, that you've still got the outer race still in the headstock. If so, the bearing you require would be 46mm OD x 32mm ID Timkin type. . The inner race would probably sit proud of the 12mm chamfer so's depth of bearing somewhere between 15....20mm probably... see what's available.
  5. Hi, I've found that the kickstart lever from a minarela (sic) 125 engine, the sort used on back kick Fantics, is the same spline. Although this type is slightly shorter (not as tall) it works for me. As for the shaft, they were sold on e bay UK several years ago, Steve Goode Motorcycles is the Italjet man...here in UK, he may know who sold these shafts, or may even have them in stock....ps Piuma....means 'feather' ...should be white frame/white tank, alloy wheel spindles, apart from that...just about the same as any 250/350 Italjet Trials.
  6. OUTLAW DAVE>>>>>Have found the video yet (from post 2006)
  7. The correct way to remove the bottom yoke steering stem, is with a press ,in a downwards direction,(as if towards the front wheel direction).
  8. Could this possibly be some kind of Chinese water torture ! But is minor compared to Senior Gonzalas, known to his friends as "Gonzo", Spanish ex pat, lives in little village Iron Action, on outskirts Bristol, rumour has it, he has seven 199b's. Spends 14 hrs a day, in his wooden shed, surounded by his bultacos, sitting on a large 3 seater settee, with a cardboard cutout of Vesty on one side and Bernie Schreiber on the other. His only pre occupation in life is to "find the forks"....I once asked him.."what do you mean"..he replied " the forks that even Senior Bulto could not decompress".
  9. Hi Tom, Had a good look at both an old used piston and a new piston, seems taper on new piston (difference between top and bottom) to be 8 thou. Whereas the old used piston. the difference is 16 thou. I also had an interesting conversation last night with the guy who had re-engineered his piston. The long and short of it.....He made a 3/8th thick dural/alumium disc, after heating piston for 20mins in oven at 200c, took measurement (while hot) at the piston inside register and made a size fit disc (fitted cold to the hot piston) cooked again at 200c for 30mins then left in oven overnight (to cool slow). I suppose you could have a measure up, to see how much your own piston has worn/distorted, and may help in getting a fuller idea as to the sort of clearances involved.
  10. Hi Fantic Tom, I have heard that it's possible to deform the piston skirt to take up excess clearance. Does seem quite drastic and i've never found it necessary to try this 'fix' myself.
  11. Would still like to see the 'letter' on top of the barrel, But seems everything is pointing towards 'D' But the other markings suggests 'E' and as the gradings go in 0-0004 thou (4 tenths of 1 thou)..looks like an 'E' piston would work. But lets reserve judgement until we recognise the markings on the barrel. Next problem would be (if you decided to fit new piston) is a piston available !
  12. One of your photos almost shows the letter we're looking for ( it's the image at bottom of photo) looks like a top of a B, if you could take a photo, including this whole letter...we could then maybe sort it.
  13. Fantic Tom, Would have been nice to have seen the markings (letters) on top of the barrel and the markings on top of the piston (in your photos), these should correspond (be the same). Next, if the barrel looks OK (but it's hard to tell definitely without really seeing the barrel in real life) If for instance both barrel and piston are (say) B, then you would need to aquire a B piston kit (piston, wrist pin, rings and circlips) also (hopefully) would include a wrist pin bearing, but I would fit a new wrist pin bearing also. My experience has been, that to refit a noisey piston, will (at some time) damage the chrome bore, Of course while head and barrel is removed...to check the big end for excessive play, it's pointless to fit a new piston to a suspect bottom end.
  14. Hi Guys, Fantic reed valve pistons, both 245 and 305 can come with different configurations for the piston inlet ports, the middle port is a puffer port, directly opposite the exhaust port, doesn't really matter (in my opinion) wether piston has or hasn't got this hole, or can be machined if you really think it's necessary. In my experience, some pistons have no holes whatsoever, but can quite easily drilled/ machined to original spec.
  15. Hi Turbo, My understanding, any 250cc Reed valve piston, wether it be air cooled or water cooled will fit, and I would have thought that 309 and later would fit, and are supposedly stronger, There is a proviso, which is, are the water cooled pistons a tighter fit in the bore and would the grading letter on the piston barrel, be at the same tolerance for both air cooled and water cooled. This wouldn't matter, if the bore was replated, as the replate would be sized to the piston.
  16. Hi Guy's, This might explain the problem with the Fantic piston, the "Tangs" on the skirt arn't really strong enough to suprt the piston square in the bore.
  17. Hi, Pistons are graded to the barrel, On top of the barrel will be a letter, usually A (smallest size) through to (H) largest size. Its imperative that you match the letter on the barrel to a corresponding letter on the piston. Only fit a new piston assembly, if the chrome bore is in perfect condition and as stated above same letters on barrel and piston. The 305 / 307 piston was a bad design, and was Fantics solution to keep up with the direct crankcase reed valve engines of the period, I understand that the later pistons were somewhat stronger around the skirt, to stop the excessive piston slap, but i've had several pistons...can't really see any difference.
  18. Hi, Pistons are graded to the barrel, On top of the barrel will be a letter, usually A (smallest size) through to (H) largest size. Its imperative that you match the letter on the barrel to a corresponding letter on the piston. Only fit a new piston assembly, if the chrome bore is in perfect condition and as stated above same letters on barrel and piston. The 305 / 307 piston was a bad design, and was Fantics solution to keep up with the direct crankcase reed valve engines of the period, I understand that the later pistons were somewhat stronger around the skirt, to stop the excessive piston slap, but i've had several pistons...can't really see any difference.
  19. It's the world we live in.......litigation or " the wonders of whip lash ". No wonder so many clubs are now LTD Companies, and why landowners, to allow trials on thier land are few. On a lighter note, does seem an over reaction to free soup, maybe just a sign, next to the soup " No real meat (only the odd oxo cube), was used in the making of this soup, also gluten, wheat & vegetable may be included"...please sign the disclaimer form.
  20. Hi Madbikez, I would tread cautiously. It would seem, that you've now had insurance revoked/cancelled. Any application for new insurance could/maybe invalidated, if you didn't mention this fact. Honesty is the best policy, when dealing with insurance, modern (information technology) insurance doesn't really allow for mistakes or misunderstandings, as your mostly dealing with faceless people. It's your interpretation of motor vehicle, which varies to that of the insurance company. Most replies on this thread, give a cryptic indication, as to the answer. Hope you get it sorted....good luck.
  21. Arnoux could be technically right, I was in North Korea last week at the Ho Chi Min Motor Show, very similar bike on display, built by Wan Kin Heavy Industries. Spoke to the sales director, looking for an English importer, preferably somebody in Derbyshire, only trouble 1000 units, minimum order ! but only 2250 Yuan per unit, so if you've got a spare £265,000 and fancy loads of Tenaci-Wong contact ...Mr Wong Yu Li
  22. Seems this thread is getting even more interesting, a bit of 'wiki' would be interesting to all parties ! Johny Rotten Dab maybe able to enlighten us, as to the data lead configuration. I've had a word with my guru/geek friend, he seems to think the lead isn't really that much of a problem, the FTDI chip should come already configured, need a specific protocol for the ECU (probably what Lotus 54 is talking about), and an analog to digital converter (maybe). My guru friends last words Volkswagon used to charge £650 for a data lead, now the're 15 quid on ebay. Sounds reminicent to trialtrials $650 CAN for an Ossa lead. I would love to be able, to give a complete A thru Z guide (a bit of WIKI) on how to configure the cable and through the download, but i'm not conversant with the Ossa, but reading (between thhe lines) of this thread, almost there.
  23. This really is an interesting thread. Trialtrial hasn't mentioned exactly what his motive is for wanting to communicate with the internal electronics, but diagnostics are mentioned in the title. I don't own an Ossa 280, my experience with Ossa ends with MAR. But I do have a little experience on Motronic systems, maybe, just maybe this may help some towards understanding the TR 280 system. 1/ Communications cable seems your some way towards getting to communicate, if you manage to locate the correct 'chip' combined with the correct soft/firm ware, you might get to the point of being able to download a series of zero's and ones, you would then need the correct software to be able to change the data into some kind of graph. I don't know how complicated the internal electronics are on the 280 system or wether you just want to read data (amount of spark to throttle opening, to rpm maybe) or wether you want to make changes. I just wonder how complicated or simple the electronics are ! My understanding (please correct me if i'm wrong) is that there is a sensor to compensate for atmospheric pressure, if so then the system seems 'a bit trick' There is a world of difference between collecting data and making changes to the internal structure, take things really softly softly, you could 'brick' the system.
  24. If your considering stripping down a falcon shock, it might be benificial to consider, that they are assembled with an inert gas under pressure. If all the pressure is not discharged and you were able to remove the internal circlip, you could have big problems and could be dangerous, the piston assembly could fly out under pressure. Inert gas is used to limit 'pump up' under use, and if recharged with compressed air, the rod displacement during compression will heat and expand the internal compressed air, the only 'saving grace' usually trials bikes aren't worked too hard, might be worth considering, if it were a time and observation trial maybe.
  25. Hi, The cases have to be split, to change kick starter shaft. Shaft length can vary, so maybe better to strip first, for shaft comparison, also later shafts, were modified, to be without 'o' ring groove, as this was a weak point for shaft breakage. By 303 production, this modification may be done, still has an 'o' ring, but case chanfered to except 'o' ring on a plain shaft.
 
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