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Cheap options would be - lowering compression as mentioned , OR - How about fabricating a longer kick start lever , for more leverage ?

Partly Covid etc. Partly the dreaded facebook , God knows why people think facebook is easier to access - its no easier to access than any website or forum I find the layout of facebook is crap, any useful info buried in people trying to sell rubbish Anyway, this is a good site, long may it continue

40/1 with a decent modern oil should be okay for trials, if doing any road riding then maybe more oil would be a good idea. I have run my Ossa MAR on this ratio with synthetic oil for years with no problems ( may have just been lucky ) personally wouldn't go any leaner than this, as I think too much oil cannot do as much harm as too little oil could do

sounds like an air leak somewhere crank seals / gaskets etc. what carb have you got fitted ? have you recently worked on the bike before this happened ?

There is this tank on ebay at moment is it the same ?

Have you tried boiling water from a kettle ? { be careful }

Sorry I have no idea what an original unused gasket would measure up to, but I do have a cheap looking aftermarket MAR gasket ( not Vintco) here in blue card that measures .020 inch Your .030 inch gasket will crush down a small amount when assembled & all screws torqued up, but the only way to see how much would be to - 1.assemble - 2. torque up screws 3. - dismantle - 4. measure gasket ( then buy another Vintco gasket to use if you are happy with measurements ) If you say the old gasket AVERAGES -.025 inch , then I wouldn't think you are far off Are the tolerances that fine on an Ossa ? I need to rebuild my own MAR engine soon, and I think I would rather have too much clearance rather than too little - better loose than something binding - I will be looking for a thicker gasket than the one I have

Hello, I have an Ossa MAR and it has always leaked a little from the gear lever shaft - probably because it doesn't have a proper oil seal - I think it has something like a felt washer on the inside and an O ring on the shaft I have renewed these and it still drips now and then There should not be a leak between crankcase halves as this has a gasket , and if your engine has recently been rebuilt with a fresh gasket then it should be oil tight - you also don't want this gasket to leak gearbox oil internally into the crankcase area, or air to leak from the crankcase area - probably the most important gasket on the engine & the hardest to change The only other place I have had a leak is from the gearbox sprocket oil seal { a new seal fixed this }- this could possibly run down underneath the engine If the leak really is between the crankcase halves , and you have paid to have the engine rebuilt - then I think you should have a chat with whoever did it , to confirm what work was done

It always makes me laugh how Pre65 people can rewrite history for Amal concentric carbs , but wouldn't want to allow a genuine 1964 Mikuni carb to be used if you had one

I mix 40-1 full synthetic in my Ossa MAR 250, I did originally use 50-1 , but the bike seems to run better and less hot at 40-1 just my opinion , and you will get people swearing by 80-1, 100-1 etc. as well as ring sealing , the oil can absorb some heat as it passes through the engine , and most importantly - bearing lubrication , some old 2 strokes have bearings that are only just up to the job, so less oil could be the last thing they need

Hello, in the past I have had a clutch basket welded to repair the same problem you have , BUT like any repair of this type success will depend on the skill of the welder & the material being welded , you have nothing to lose trying. I have also owned a bike for many months with no Clutch issues , and only found the clutch basket broken after removing the clutch cover to change the kickstart oil seal. There was one finger missing, but the clutch was working fine, and I expect the previous owner just took the cover off , removed the broken piece to eliminate the rattle it would have made and reassembled everything hoping it would work okay. Not recommending you do this , but if its the only thing stopping you riding the bike, maybe you could try this and carry on looking for a basket in the mean time You could try - cmsnl.com for a new part , {if they have one they are rarely cheap} or just use their website to get a part number to google

Good points about the problems you may have with modern fuel in a Fibreglass tank { or a plastic one }, using an alloy tank has to be preferable to avoid any problems going back to the original question about fibreglass tanks being banned {for road use} - I think the law was that a tank had to be metal , so this obviously excluded fibreglass & plastic of any kind, but I don't think this law lasted long as I know some BSA road bikes had fibreglass tanks in the late 1960s , and There are some 1980s road bikes with plastic tanks , it must have been a short lived 1970s law that got removed

I am reasonably sure you are okay these days with a Fibre glass tank being used on the road As far as i can recall , there was a law requiring metal petrol tanks in the 1970s / 1980s ? But that law has been removed a long time ago I could be wrong , and if I am then someone will surely correct me - but there are plenty of modern cars & modern Enduro / Trials bikes that are road legal , with plastic tanks

It should get easier ,with each nipple you remove the other spokes should get looser , which might mean you can get more room to get some grips on them and crush them / turn them I was lucky, on mine as they had all mostly turned to white powder - not much Aluminium left

If they are the same as on my Ossa MAR, then they are 3.5mm. On my bike the stainless spokes on both wheels were perfect , but the Alloy nipples were corroded and nobody seems to sell nipples in the size required I was reluctant to buy 2 x sets of stainless spokes { at £80 a wheel } I managed to find somewhere that sold nickel plated brass nipples of the right dimensions at a reasonable price , with just a pilot hole. then I got a 3.5mm thread tap and threaded all 72 nipples { yes this was tedious , but the money saved payed for some other parts } I cant remember where I got the nipples , it may have even been a cycle place ?

IF the process of - having a referendum - then negotiating a leaving UK deal - then negotiating a joining EU deal , is as slow and long winded as Brexit was , then don't worry , we can all ride the SSDT for many more years

They look like they are just too short, and forcing them to fit wont be a good idea - could break when fitting, or worse still could break later when running I would try and get some different ones personally

If you think ethanol could be a problem , there are options you can take to reduce the chance of problems Fill your tank on the day that you are using the bike, then drain tank & carb after you finish riding { ethanol damage is usually a slow process, not instant } As already mentioned - Use ethanol free fuel - not always easy to find + sometimes expensive Remove the ethanol from your fuel - I have never done this , but there were a couple of places selling kits to do this - Ethanil.co.uk, I think was one company that sold a kit for this purpose . { i have no idea how successful this is , but the kit wasnt that expensive }

Does that not already happen every summer when the French ports go on strike ? ? I have never ridden a trial in Kent , will have to see if I can get to one in 2021

Some DT100 twinshock , clutch cover may fit ? Flywheel side , if you are using standard flywheel then only TY will fit over it believe ? if running smaller flywheel then maybe a DT cover ? and the TY125 of course , but I think this is a euro only model { Disclaimer - its years since I had one and played around with different covers , I could be wrong on some or all of this }

No, I don't think prices of bikes & spares will increase anymore than they would in previous years every year prices increase due to - inflation , raw material costs , wage rises , currency exchange rates etc. etc. cancelling Brexit would not change any of these things Covid may have an impact on prices

I cant see Brexit having any effect on any Trials anywhere in the UK I can see Covid effecting trials during 2021 , but that will depend on if it gets worse or better As for a massive financial crisis , its possible , but you wouldn't think so if you saw all my Neighbours - most seem to being having a house extension built or new kitchen / bathroom { never seen so many skips in the road }

Yes, I think your right, at least for the early part of the year but even that depends on things getting better not worse

Yes, got the same hole on my MAR

The middle part looks the same as my own MAR, the silencer - I cant remember ever seeing one like that on an Ossa the front pipe could be TR77 { they are that shape - MAR is much shorter }