chris_ Posted February 14, 2012 Report Share Posted February 14, 2012 I have been over to the intros to say "hello" and now hoping to pick up some much needed advice as I start out on getting my "new" 247 up and running again. The frame number is 21M 12511 which I understand makes it late 1973 or early 1974 There are a few "issues" including non-original bits such as the engine, plus some bodging in the past. For example, the rear mudguard is too high and has caused the damage to the seat, plus the front wheel appears to be the wrong way round. There is also a fair amount of mechanical work needed as every wear and tear item looks to be thoroughly worn out. I can't wait to get started! Quote Link to comment Share on other sites More sharing options...
greeves Posted February 14, 2012 Report Share Posted February 14, 2012 (edited) Hi Chris: Nice bike, I have one like that, it is a very good bike for classic trials. Just one weak point; the gear box, specially first gear normally jumps out if it is not engaged properly. Take your time to engage it and move clutch and wheel a but while you engage several times to be sure. Apart of that a bike that gives no problems. The colour of the frame should be grey, and the engine side cover is for an earlier Cota, not that model. It should look as this one. I would very gladly buy that side cover if you want to give it it´s original look, as there are tough to find for earlier models. Do the engine numbre match with the frame? As the frame looks from a more recent model. The engine really looks as an Impala engine, the one earlier Cotas had. That rear sprockt looks too small, my advice try 9 / 48. The front wheel should be the oposite, just look the brake lever !!! Enjoy your restoration !!!! Edited February 14, 2012 by Greeves Quote Link to comment Share on other sites More sharing options...
tonybroad Posted February 14, 2012 Report Share Posted February 14, 2012 looks a good project, first rode one in late 70's - i've got a good 247 tank seat unit which i plan to take a mould off at some stage so i can make a 'new' replacement one, got 348 and 349 ones too but it's all a work in progress when i get time good luck keep us posted tony Quote Link to comment Share on other sites More sharing options...
chris_ Posted February 14, 2012 Author Report Share Posted February 14, 2012 (edited) The engine number is "25 10" Edited March 1, 2012 by Chris_ Quote Link to comment Share on other sites More sharing options...
keychange Posted February 14, 2012 Report Share Posted February 14, 2012 I don't think the problem is just the rear guard the frame appears to rise too steeply causing too much pressure on the fibreglass cowling - I had this problem when I tried fitting an old standard 247 cowling to my 1976 247 - so maybe the frames changes and it was just an older model cowling - although they are all very week and prone to breaking around there simply from riders reaching down to pull the rear end around. The barrel looks right but carbie inlet is completely different to my 76 model as are the crankcases much more like this 1969 model http://www.trialscentral.com/forums/topic/39529-cota-247-1969/ Front wheel definitely wrong way round ..how did they do that? Does it have the bolt for the support rod - if not that is why they reversed it - in order to turn it into sort of trailing mode shoe. So looks maybe a 75+ frame ( they were black) with earlier engine and god knows what front hub - have fun Quote Link to comment Share on other sites More sharing options...
greeves Posted February 14, 2012 Report Share Posted February 14, 2012 (edited) Hi again Chris: Funny engine you have there. Have a look to this bike I have and that I am actually restoring. Engine is 21 - 1941. Your´s can be really a prototype, but the thing is then it should have the big Impala hubs, not those ones as in my Mk2 and Mk3 bikes, also look the sliders, there is a big difference between the ones the Impala engines (Mk1 and Mk2) had and the Mk3 models (also with the gear in the right). Very odd. Edited February 14, 2012 by Greeves Quote Link to comment Share on other sites More sharing options...
chris_ Posted February 14, 2012 Author Report Share Posted February 14, 2012 Thanks very much for the replies so far, it is much appreciated! I agree that the front wheel is definitely the other way round compared to normal. This is what it looks like at the moment; The seller told me that these were "works" hubs rather than standard production ones. The difference (apparently) is that the standard (smaller, 1970+) hubs have fins or ridges, but the ones used on the works bikes were smooth to stop dirt building up. I don't know if this is true or not as I have not seen a standard bike up close to verify. I don't know if someone could kindly check or confirm? Quote Link to comment Share on other sites More sharing options...
chris_ Posted February 14, 2012 Author Report Share Posted February 14, 2012 In reply to a couple of other points; -The carb looks to be a bit odd as well. It is an Amal carb as you can see, the number on it is "626" -I agree that the rear frame does look to be bent and sitting higher (compared to Greeves' lovely example) Talking through some of these points with the seller, his view was that the bike could well have been a "works" bike, given that it has some of these peculiar features. The frame and engine certainly seem to be a few years apart and who knows how they came together? I respect the opinion of the previous owner (given his personal background) but I suppose that many of these end up like Trigger's broom with bits getting swapped an replaced over the years. It is certainly intriguing, and even if it is a bit of a Frankenstein bike, I love it! Quote Link to comment Share on other sites More sharing options...
greeves Posted February 14, 2012 Report Share Posted February 14, 2012 The fron hub in my Mk2 is different, the rear the same. Also would like to know Chris the kind of exhaust system your bike has; the early one that crosses from left side of the barrel to right side of the bike underneath the seat and with no final silencer? Or the one with the final silencer? Carburettor in my Mk2 (Impala engine) is Amal 626 Pilot = 25 Main jet = 160 Needle jet = 106 Slider = 3 Quote Link to comment Share on other sites More sharing options...
chris_ Posted February 14, 2012 Author Report Share Posted February 14, 2012 So it looks as if it has the right carb for the engine type at least. Regarding the exhaust; this is the only picture that I have on my pc and I haven't taken the seat/tank off yet, so maybe you can tell from this photo?. It does not have the external/rear silencer, so from what I understand, it looks consistent with the early engine. Quote Link to comment Share on other sites More sharing options...
cotacrazy Posted February 14, 2012 Report Share Posted February 14, 2012 It looks like a 1971 / 72 Mk 3 to me, the last year of the bulbous tank and right hand gear change but with the small hubs and newer forks.I had a 73/74 Mk4b back in the day which was a fantastic bike, revved its nuts off!and lefthand gear change. Quite a few people used to turn the fins off the hubs to save a bit of weight / easier to clean,so i dont think yours are anything too special, but it does look a genuine bike,have fun restoring/riding it! Quote Link to comment Share on other sites More sharing options...
jordi Posted February 14, 2012 Report Share Posted February 14, 2012 I would think its a 1971 Mk 3, I had one just the same, small hubs and a round logo on the engine casing. Quote Link to comment Share on other sites More sharing options...
chris_ Posted February 14, 2012 Author Report Share Posted February 14, 2012 The frame number is 21M 12511 so according to this, it dates it after October 1973 but before Feb 1974 Oct. 1973 21M 12,115 Filter element, "Twin-air" Black frame version DATE Feb. 1974 21M 13,107 New black frame. Quote Link to comment Share on other sites More sharing options...
martin belair Posted February 14, 2012 Report Share Posted February 14, 2012 (edited) The engine is interesting, and there is a bit of a story behind it. The engine number is "25 10" which, from what I have read, makes it an Impala engine (25 series). The gentleman that I bought the bike from was a Montesa factory rider in the 60's and 70's and had been involved in the original development of the 247 all those years ago in Spain. He told me that some of the pre-production and early 247's began with Impala engines. He also recalled having a "works" bike from the factory with such an engine for a particular competition. Chris, the 25 25 10 10 numbers are for matching the crankcase halves during production. The true serial is on the front motor mount. It should begin 21M... Based on the intake manifold my guess is it will be a number less than 21M0500. The carbs used on the early Cotas was an IRZ (spigot mount). It looks like you have an early model motor and tank with a later model frame, wheels and forks. Edited February 14, 2012 by Martin Belair Quote Link to comment Share on other sites More sharing options...
chris_ Posted February 14, 2012 Author Report Share Posted February 14, 2012 Chris, the 25 25 10 10 numbers are for matching the crankcase halves during production. The true serial is on the front motor mount. It should begin 21M... Based on the intake manifold my guess is it will be a number less than 21M0500. The carbs used on the early Cotas was an IRZ (spigot mount). It looks like you have an early model motor and tank with a later model frame, wheels and forks. Hi Martin Armed with a rag and some de-greaser, look what I found; Thanks very much for the pointer and thanks to everyone so far for your input, it's much appreciated Quote Link to comment Share on other sites More sharing options...
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