Not sure which tank you purchased or from what vendor.
Simply a FWIW, my buddy purchased an aluminum tank for his MAR. While it looked great, with use he found the tank had a couple of small leaks along the welded edges.
The guy we use for welding is aerospace certified. He spent some time welding the tank and would smooth the edge back as it was with no bead of weld showing. Try as he might, the seam would open slighly in another spot. Point being, it appears the edge is a very thin joint after being sanded smooth.
Ultimately, I asked our welder to do a nice functional but pleasing to the eye bead around every seam. Once polished the tank looks fine.
The tank came from Feked.com snd i went for the polished tank with monza cap? . Thanks for heads up on the leaks I can see how flattening the welds would weaken the seam, I will have to keep an eye on it.
Thanks for the advise lads but I got it fixed. I took a chance and spread the Tank using 2 pieces of wood and A couple of tyre levers. Still slightly narrower than orriganal but fits snugly on mounting rubbers now.
You may well have the correct tank, but the buck that was used to make the tank may be out, where did you get it from? Is that 10mm each side or overall? If this is the case then you only need 5mm clearance to be obtained either side. Have you contacted the supplier of the tank, they may be able to offer advice or suggest a fix as this won’t be a one off. You could try gently persuading the tank guides (for the rubber blocks) to move inwards by pressing against the area with a flat piece of plywood, a 2mm inset leaves 3mm to find. Try the tank on the frame with no rubbers and see what you have. I dare say if you could have been a fly on the factory ceiling ar Ossa, when the assemblers fitted the tank I suspect that there would have been a fair bit of pushing going on the achieve a fit. Overtime the tank would have given anyway what with the riders legs pushing up against the tank. Have you measured the old tank and have you checked to see if there is any depressions around the tank slider mounts? Have you got the correct tank rubbers? Lube the slide mounts with silicone and the rubbers and try to gently persuade the tank on, shaving a little (1-2 mm) off the heads of the rubbers may also win you a little extra clearance. I hope you find a satisfactory fix ?
Im doing up a '74 Ossa 250 MAR and ordered a the replacement alloy tank for it. When the tank arrived it looked great but its too narrow by 10 mm at the front where it goes over over the rubber mounts. I can modify the dowls and rubber mounts on the frame with a grinder and shoehorn the tank on but would much prefer get the correct tank..
Hi Ive been dabbing in trials for over 40 years now and still love rideing trials bikes in the dirt. Apart from the fact that trials riders are the most genuine of people to hang out with its great to be on this forum as there is very helpful posts and advice here too.
Ossa MAR alloy tank.
in OSSA
Posted
The tank came from Feked.com snd i went for the polished tank with monza cap? . Thanks for heads up on the leaks I can see how flattening the welds would weaken the seam, I will have to keep an eye on it.