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dr nosh

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Everything posted by dr nosh
 
 
  1. Thanks FeetUpFun. Thats pretty much how I found the sequence in the end. (I started off with the airbox in position, all looked a bit of a tight squeeze. With the carb fitted and vertical the brass nut under the float bowl is touching the top of the crankcase. In fact I can only just get it vertical. That does not seem quite right to me. Should there be a gap here? Can you take a photograph of yours?
  2. Anyone mastered the art of assembling the carburettor to the air filter box along with the rubber adaptor to the barrel and the 2nd rubber adaptor to the air box? I'm still trying. Also, found so far, Why is the carb drain plug actually touching the top of the crankcase? Is it meant to do this? Doesn't seem quite right to me.
  3. Now about the eccentric adjuster. When this is assembled over the M6 stud, the adjustment made, and the locking nut is tightened up, there is still movement in the adjuster plate. Should the adjuster plate be locked tight in position? If so, then the back of the eccentric adjuster is proud by 0.2mm preventing it being locked tight? Is this correct, or have I got to machine this so its 'sub-flush' therefore allowing the adjuster plate to be locked preventing movement?
  4. dr nosh

    Cota 248, 1981

    Oh. Welding magnesium....not easy. I was lucky, noting cracked or broken on the engine, which is more than I can say for the state of the frame and cycle parts. Anyway, back to the question about the gearchange eccentric adjuster. Should this lock the plate in position? Anybody got any views on this?
  5. dr nosh

    Cota 248, 1981

    Now about the eccentric adjuster. When this is assembled over the M6 stud, the adjustment made, and the locking nut is tightened up, there is still movement in the adjuster plate. Should the adjuster plate be locked tight in position? If so, then the back of the eccentric adjuster is proud by 0.2mm preventing it being locked tight. Is this correct, or have I got to machine this so its 'sub-flush' therefore allowing the adjuster plate to be locked preventing movement? Thanks
  6. dr nosh

    Cota 248, 1981

    C clip sorted. Just finished sorting the gear change mechanism. Very notchy. The pawls were all good, but the plate that they slide across had a groove worn in it and a burr. Stoned off the burr, and ground a small rad on the leading edge of the lower face of each pawl, so the pawl now slides across without the leading edge catching. Re-assembled and now much smoother. Next. Fit engine to frame.
  7. dr nosh

    Cota 248, 1981

    Thanks. There is no separate breather on the clutch case. I think this vents through the gearbox. Good point on using clear tubing. (The gearbox tube and threaded coupling is actually blocked solid with gunge!!). Another question. The final drive sprocket is a push fit onto the g/box output shaft, and this is then followed by a 'sprung loaded cup' over an O ring on the shaft itself. In order to keep these on the shaft there must be a circlip or something that then fits into a groove on the outer end of the shaft. I can't make out what this is actually supposed to be or look like from the illustration in the parts book. p/n 6763.165.
  8. dr nosh

    Cota 248, 1981

    Now at the stage of getting the engine back together, after a bit of a long rebuild. Anyway, there is a breather at the rear of the motor, from the top of the gearbox, and also a breather in the magneto cover. Are these actually necessary? Is it a good idea to remove them? If they should remain in place, should I; Gearbox - Run this up into the bottom of the air filter box? Magneto - Run this up the frame to under the tank with a 1 way breather on it? Advice appreciated. Thanks.
  9. GasGas249. Thanks for sharing the interview. Very interesting.
  10. Can anybody post up pictures of how the rubber front sprocket cover fits please. I have the cover, below but the fittings to attach it are missing. I can see from the instruction manual that there are some fittings, but the pictures are too small to see clearly. Does it push onto some studs? If you could include some pictures of the cover removed in order that I can see the fittings that would also be very useful. Thanks
  11. Thanks Combivan. I see what you mean.
  12. Hi Kombivan. Can you post up the web address details of the Montesa board that you mentioned in your post 15 October 2014. Always after information to help me in my Cota 248 re-build. Thanks.
  13. Hey. Good timing. I'm re-building a 1981 Cota 248. I have finished all the cycle parts and have now started on the engine this weekend. (Tank / seat unit picture) Crankshaft weight came off easily with puller M30 x 1.5 RH. Clutch and basket came off easily. I'd already spotted the 3 pins inside the part holding the clutch basket on. Now stopped because like 79Cota348, I cannot move the primary gear. Samwisemcg. That puller looks right. Can you post up the e bay number please. Thanks
  14. Found the chain tensioner. Brand new, from a dealer....universal.Fitted......but way out of line with the chain. Main part of the spindle replaces bottom M10 engine bolt. Will need to remake this longer. The arm pivots on a M6 screw in the end of the main spindle. But the pressed in bush in the arm is i/d M10. How is that ever going to work reliability! Will make a bush to match an M6 stud for the arm to move on. Can be cleaned/lubricated regularly. Trying to do some more this weekend.
  15. Thanks tayld. Confirms my thoughts. The T bracket is new, so will watch out for eventual wear. I do have a new chain tensioner but not fitted as yet. Going to do this at the weekend...I hope.....time permitting.
  16. Can anybody please explain how the chain plastic/rubber tubes fit at the front end. I can see how they fit over the rear wheel sprocket using the alloy T bracket, but at the front the top run just rests on the swinging arm, and the lower run just rests on the frame. Is there supposed to be some bracket ? I have not fitted the chain yet, but even with that fitted, it looks like they will just rest on the chain. Any clues?
  17. Hi. I'm currently building a 182 248 - red frame, white tank, road registered. Simple to work on, requires puller for mag flywheel. Spares fairly easy to come by, In Motion and Spanish specialists. Obviously not ridden it yet, but quite a few 248's early and late in our club. So still popular. Hope this helps.
  18. dr nosh

    Montesa 349

    Well that is a very nice looking machine./ I am currently building a 248 model, looks very similar to yours. I've just bought new chain tubes and alloy bracket to fit to the rear wheel spindle. Made up some small alloy spacers to allow fitment to the alloy bracket. How are the tubes fixed at the front? At the moment mine are just resting on the chain. This cant be right, can it? Also, how does the rubber over the front sprocket area? Photographs would be useful. Many thank
  19. Just arrived : Another part of the jigsaw. Think that these will also fit 249 as well.
  20. Turned up a set of handlebar shims - Fairly straightforward - Bore tube 7/8", turn down O/D to fit into the clamp halves (bottom clamp half is different size from the top half). Had to turn to fit, as the clamp half is not a true 'half', so the diameter could not be measured. Part off to the required length and you have a 'ring'. Turn up a 7/8" plug to fit into the 'ring' and use a toolmakers clamp to hold in the clamp half. Use a model making saw blade (like a junior hacksaw but finer cut) to 'split' the 'ring'. Had to make 2 sets like this one to fit clamp top half, and one to fit clamp bottom half. And I was reading in another thread about 'overpriced restorations'. I think that you have to consider the amount of work that has been put into a restoration when deciding on its 'worth'. Anyway, another question, , chaintubes. How to these fit to the alloy bracket on the rear wheel spacer. I can see in the parts diagram 4 'buttons', which appear to be held to the alloy bracket by an M6 nut/bolt. How does the tube fit over this button? Is it a push fit to allow the tube to 'float'. Pictures would be useful. How are the tubes fixed at the front end? Thanks
  21. jms61. I'm currently building a 1981 Cota 248 and am missing this part to hold the brake cable. I welded a s/s M6 nut to a s/s bolt long enough to locate and bolt through the mudguard stay. Weld the nut at right angles to the bolt thread. When cold, cut a slot in the nut to allow the cable to pass through. Screw the cable adjuster into the nut. Bob's your uncle.
  22. Next problem is the fit (or not fit) of the handlebars. Bought a pair of Tomaselli, but are actually dia 22mm and will not tighten up in the clamps. Are there bars, swaged with larger dia in clamp area? Will I have to turn up a set of shims to fit these correctly??
  23. Hi Jimbo. I see the next meeting is 18th Nov (next Sun). Could not make last meet, so hoping to get to this one. Front wheen fitting now sorted. Ended up making new spacers. Need a bit more help now. How and where does the chain tensioner fit, and does it need a spring to operate ? Also, what holds the outer front brake cable in position on the forkleg ? Is there some fitting ? Pictures would be really useful. Thanks.
  24. Hi Jimbo. Thanks for your response. What a coincidence! I'm actually in Kings Lynn and will be rejoining Dabbers. Used to ride with them on a TY175 about 15 or so years ago. Are you going to Little Thetford on Sunday? Looks like I will crank the torque arm to suit. OK on fitting grease nipples to the s/a.
  25. Just building up a 248 bought as a rolling chassis, motor (head/barrel off) and box of bits. 1st headache. Can anybody post up photographs of the front brake, from the left and directly from the front. With the front brake assembled to the wheel and the wheel inserted into the forks with speedo drive and spacer on r/h side the brake torque sits about 10mm from the fixing lug on the fork leg. The torque arm is presently straight or flat. There is no evidence of it being straightened. However, should the torque arm be shaped in order to lie flat against the fork lug? There is a steel bush pressed into the brake plate. Is this correct? 2nd Query Really. One the main frame section, there are 2 ribbed tubes in the vicinity of the swinging arm. They are not grease nipples. What are they exactly? Many Thanks
 
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