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ScottyA

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  1. ScottyA

    OSSA MAR oil leak

    Thanks Trialman, No sign of gasket poking through only what I assume is a white assembly/gasket paste or something. I’ve attached a picture. I tied this string over where I suspected the leak is to stop the flow continuing downwards. it’s at a slightly higher level than the drain plug and as you can see in the pictures it’s wet with oil. So pretty confident it’s not the plug and no sign of it flowing from another source higher up . Thanks for the info, I’m going to give the builder a ring Scott
  2. ScottyA

    OSSA MAR oil leak

    Thanks Djr You’ve confirmed what I suspected, I just didn’t want to go kicking up a fuss if it was a well known fault that they all came out of the factory with. I think I’m going to clean it off and start the process again to see if I can be confident of the source Leaks aside Im really fond of the MAR, they are lovely little bikes Thanks again
  3. ScottyA

    OSSA MAR oil leak

    Hi everyone , I’m hoping to get a bit more advice regarding my MAR. Over lockdown I’ve rebuilt the bike which I inherited in bits, I had never seen one in the flesh so was a bit lost initially but got some great advice here. The bike is pretty much done now, I didn’t attempt an totally accurate restoration just wanted a presentable bike I could actually use. And after some debate I decided to get the engine professionally rebuilt . Riding it round the garden it seems to run well but I have an oil leak(s) From reading other threads it seems that one of the leaks is common with other MARs in that there’s a small weep from the right side of the gear selector shaft. Don’t think it adds up to much and I’m not too worried. I initially thought the other leak was from the sump plug as that’s where the drips formed but having changed the washer and re tightening the plug I now think it’s weeping from inbetween the crank cases adjacent to the plug. I could be wrong, the oil is clean and its a slow drip so it’s hard to track. Volume wise it’s literally just a drop or two over a 24 period while the bike is parked up. However, this increases if the engine is running. Its hard to measure accurately while using the bike but if I run the bike for 10 mins, shut it off and put a tray underneath I will have a patch of oil about the size of my hand by the end of the day . This continues for a day or so then reduces back to the odd drop After all my rambling here’s the question. Is what I’m describing normal? If this is what I should expect from an old Spanish trials bike then fine, I won’t lose sleep over it. But if not I’m going back to the guy that rebuilt it . Just trying to set my expectations really! I will try to include a pic of what I collected in a Chinese container over about 6 hours post the engine running. As I said if it hasn’t been running for a day or two the leakage is fairly insignificant . Thanks in advance! Scott
  4. I’m kicking myself now... ? seems so obvious when it’s pointed out to you Thanks for the help! Scott
  5. Hello again, Some more questions if you guys don’t mind.. I’ve got the manual and I’ve searched the forum but am still unsure about a couple of things. Firstly I’ve got an MK1 ( I think) with MK1 engine ( number M -342454) I’ve found the gasket and seal kit on the inmotion website but it only shows one set / option for a MAR 250 with no reference to production years. Are all 250 mar engines identical? I could be totally wrong but I seem to remember seeing reference to a smaller crank on the early MAR on a US website.Just wanted to double check before ordering . Im also a bit confused on the rear brake cable routing.. the manual I have isn't clear to me and because Im building this from bits in a box I can’t work it out. I’ve never actually seen a complete ossa in the flesh All the components on the shaft attached to the brake pedal were already in place out of the box I got it in. But when I installed the shaft it would have resulted in the cable being pushed rather than pulled by depressing the brake pedal. Unless I routed the cable over the top of the swing arm and through what seemed a really tight angle which just didn’t seem right . I took the front cable attachment ( circled in pic ) off and turned it 180 degrees so it pointed upwards while Installed ( pic 2 ) . That would have the cable pulling in a natural sense but results in the brake pedal pointing down way too much before being depressed . What way should it be configured? Any way I’ve tried seems wrong. I might just be being stupid , maybe I’m missing parts . Both equally possible! Thanks Scott
  6. Thank you Woody, I’ve had a look at the exploded engine diagram and can see that there should be another pushrod on the other side. It has the same part number so at least I know that what I need is identical to what I already have. I will see if I can get my hands on some rings that are suitable too Thanks for taking the time to get back to me, without having people to ask I would probably give up. I’m in over my head and it would be impossible without some advice ! Cheers Scott
  7. Hello again everyone, A good while back I asked some questions regarding my 250 MAR . I got some great info but as expected I’m going to need more help! Ive only just got round to working on it now . I was too busy but like most people I’ve suddenly got a lot more time on my hands these days ! So far I’ve cleaned and painted what I can, I’m not sure the silver and green I’ve managed to get is quite right both are a bit too bright . I’m not too fussed on that, I just want a working bike that I can ride. I’ve got a rolling chassis , i need some parts ( see below ) but in general the build is fine apart from the engine. I’m up for learning, and I’ve got some manuals but I think this engine has had a rough life and some unsympathetic previous owners. Because of that I think this job is going to be a bit trickier. One thing that I’ve noticed is that there seems something amiss with the clutch. As you all know, the clutch cable attaches onto a lever which turns a vertical shaft and it in turn acts on a horizontal shaft that runs through the sprocket . This little rod or shaft just shoots in and out with zero resistance. It goes in so far that you can’t see it, but if you turn the engine on it’s side it falls right out again. So as far as I can see there’s no way that can transfer any pressure through to the other side of the engine.any ideas? I’m assuming that there’s something not right internally and so the engine will require to be split to investigate. I will try to attach pictures of the shaft I’m referring to I was up for having a go at the more standard stuff and change gaskets, seals, clutch plates etc but if there’s likely to be damage that requires experience to resolve it might be time to leave the engine into a professional . when I got the bike it was in bits already , on removing the head I noticed the piston rings are missing. I know the bike had been in bits for decades and the head was only on loosely . The piston and bore look in good shape. Piston is stamped with a 72 and a 4 . I’m not sure what that means in terms of piston size as my manual refers to the sizes in letters . Would you think it’s possible to order rings to fit this piston? Or is it a no brainer to just fit a new piston ? The engine number is M342 454. Which makes it a MK1 with a smaller crank apparently ? It was mentioned when I looked and engine rebuild kits Aside those queries my plan is to order up a gasket kit crankshaft seals brake shoes brake and clutch levers ( They are missing) chain and sprockets shocks or springs.. I have working shocks but the springs are cosmetically damaged. If I can just change the springs I will Ive found all of the above online, just thought I would ask here before ordering incase there’s something else I should do ! Or otherwise ! Thanks in advance! Scott
  8. Just saw that woody recommended a ford silver in another thread.. will try to get some of that
  9. That’s Brilliant, thanks guys. I’m away with work at the moment but when I get home I will check the bits over again armed with your info. Seems everyone is convinced it’s a MK 1/2 frame so should be silver. It needs painted anyway so I may as well try to get the correct colour. Does anyone know a good match for the silver that would be readily available in the UK? Same for the green paint but as I’ve got the tank and side panels ive got something for comparison so it should be easier to sort. I’m considering having a go at the painting myself or the fun / learning exercise. I figure that if I’m not happy with the result I can get it done by a pro after and I haven’t lost out on much. Any tips would be appreciated! Thanks again !
  10. Hi there, First time using the forum and I’m looking for a bit of help with my Ossa. My dad and I acquired it many years ago and it was our intention to get it back to working order and maybe use it for the odd trial. My dad passed away before we got round to it so now I’m going to have a go myself. My dad was an engineer and knew the history of the bike. I’m ok with routine maintainance and minor repairs having owned modern MX bikes but have never done a restoration on a classic so it’s a bit beyond my experience/ skills. The bike is currently dismantled in boxes etc and has been like this for years im probably going to get the engine rebuilt professionally and then I will know it’s all sorted. What im looking for here is confirmation that it actually is a 250 MAR and if so what colours it should be (as I’ve seen a few variations. ) Also any general tips and good sources for parts / manuals etc The tank ( alloy) is completely green and the frame is black ( with surface rust). So from what I can see it’s either been painted or isn’t an MAR ( only had a silver frame ? ) Mudguards are white plastic. Im going to try and attach a few pics of some of the bits. Can send more if it helps. Ultimately im not going to try and make a show bike as I’m going to use it but I would like to make it more original and presentable Thanks in advance! Scott
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