Thanks for the info, but let me ask you a question. Why do you need gaged thrust washers (within tenths of a mm) for then on the top end if the bottom controls. I would think it is the other way around, especially when you have substantial play (mm's) on the big end??
Does anyone have an idea of what the top end play on the small end of the crank should be for a 349 or later version 348?? I am trying to get the adjustment right with different size the thrust washers but am not sure what the minimum should be??
Hi, thanks for the advice. This bike is driving me a little crazy. New connecting rod, piston, rebored, all new bearings, I recentered the crank with the shims...I don
Hi maybe some out there can help. I am rebuilding a Cota 350, which has basically the same engine as a 349. I had the crank rebuilt and the rod used is not a Montesa original rod but a Metrkit rod which is aprox 1 mm thicker in the rod width, the base and top being the same as the Montesa rod. I recentered the crank using some of the different guaged spacers, and got everything lined up with an even distanve between crank halfs and the rod centered in the middle of the crank cases. Everything seemed ok until I put the piston and cylinder on and there is a noise as I turn the engine over. From what I can see, the connecting rod is shifted to one side as the engine turns and rubbing slightly against the crankshaft halfs as it come around.
There isn't a lot of room on the lower ened since the rod is thicker. I used the same small end bushings and didn't expect this to take place, it seem that the piston and bore is slightly off center and moves the rod over after a couple revolutions....any tips, help??
I believe the cranks are the same. The bearings used, cranks weights and electrics are all the same as far as I can see. I have two engines on my bench right now. It is true that the 349 show a asymetric cranks wehere as the 348 are round. I don't think there is any difference in the crank case halves. Was the engine running when you took it apart?
Hi, as others have mentioned, the Mats Nyberg site has a manual for 5 speed models that is good for you. This manual will be a big help. Ossa engines are relatively simply with quite a few less parts than others. Parts needed van eb bought from a number of places, Ron Bors in the US Ossa world, Keith Lynas. Colmenero here in Spain..it depends what you need. Good gasket sets are availbale from here in spain and they can be found on ebay.
Parts diagrams can be downloaded from OSSA World. All bearings are standard and can be bought at any bearing place, seals the same thing. If you have any problems, let me know. Take care and send pics when it is done.
Ya, I would be interested in seeing the puller, the nut on the weighted flywheel was over torque, i am rebuilding three engines at the moment, 2 348 and the 350, the 348's have gone smoothly, but i've had nothing but problems with the 350...this gear is on very, very tight.
Hi, I am rebuilding a MontesaCota 350 and have a problem getting the primary drive gear off the crank...it simply wont come off. The nut on the weighted flywheel seemed to be overtightened and now the gear is a bear to deal with. I have messed up a brand new extractor...any ideas??
