micknal Posted November 21, 2011 Report Share Posted November 21, 2011 Gents I have recently inherited my fathers Sherpa T 1971 M80. It has stood at the back of his garage for probably 20 or more years without being started. So I have decided to try and get her going. First took off petrol tank and carb which were all gunked up. Cleaned all the jets with airline and ensured all residues were removed.Removed fuel tap and thoroughly cleaned ( replaced cork washer ). Replaced fuel lines as these had gone'hard' and brittle. Thoroughly swilled out the petrol tank. Checked for spark and was pleasantly surprised to see a nice 'fat' blue one. Put some nice fresh petrol in tank and flooded the carb. Moment of truth , I kicked , nothing , and kicked , nothing , this went on for about 5 minutes and then the penny dropped somethings wrong. So I resorted to an old trick ( taught to me by my Father in my Francis Barnett years) , drop of petrol on the plug ( after removing from engine ) set light to it and let it burn down. Couple of squirts of petrol down plug hole , replace plug and kick. Instant life for about half a second , so problem can't be too bad ( thinks to self). I tried kicking over for longer ensuring carb was flooded and even had the throttle wide open but couldn't get a wet plug. So the problem with the engine is perceived as this - Assume electrics okay as engine runs if fuel is in combustion chamber Carby is cleaned and as far as I know functioning as it should do. Petrol is new therefore not old and stale. For some reason fuel is not being drawn into combustion chamber. Unfortunately my experience with 2 strokes ends here. I seem to recall the bike was always a pig to get started but once running and warmed up was okay. I'm not quite sure where to go from here apart from pulling the carby again and seeing if I might have a blocked airway. I would like to invite any suggestions from you guys, who have obviously much more experience with Bultacos than I do. Many thanks in advance. Micknal Quote Link to comment Share on other sites More sharing options...
hewson Posted November 21, 2011 Report Share Posted November 21, 2011 Hi there , start with replacing the crank oil seals as its been stood a bit..... Quote Link to comment Share on other sites More sharing options...
pschrauber Posted November 21, 2011 Report Share Posted November 21, 2011 Yep crank seals may be stiffen too and if you can't get the engine running you can't determine if the seals really are worn out / stiffen or not, (see below). I personal would first determine why gas support might be a problem as I understood from your writing. Have you checked the petcock? (If you hade so much gas gum and other debris in the tank and carburator I would check the petcock too). I had the same problem with my Sherpa that also stood for 10 - 15 years in a garage. The gas turned in a gum like substance and under this jelly there was a layer of crystalline honey colored coating that could only be removed mechanically. I would therefor also look at the ducts of the carb very accurate if these small cunductions aren't clogged too. (This happend to the carb of my Sherpa, sadly the carb body was tehrefor a completly loss even different ultrasonic baths couldn't fix that issue). BTW: check out the rubber for cracks leaving air leaks too. When the bike is running again I would then first check the crank seals. let the bike run with open rotor case just ideling, you don't need the clutch, (assume your kill starter works). By spraying brake cleaner in the gap between rotor and engine case there should happen nothing if the seal on this side is OK. If the seal is worn out the engine should rev up, (you can also use start gas for cars for this procedure). This works also fine for detecting airleaks between manifold and carb. Quote Link to comment Share on other sites More sharing options...
tankygsy Posted November 22, 2011 Report Share Posted November 22, 2011 Check plug gap.. Reduce it by a few thou. And try again. Quote Link to comment Share on other sites More sharing options...
micknal Posted November 22, 2011 Author Report Share Posted November 22, 2011 Many thanks for your suggestions. tankygsy - Tried this today but unfortunately didn't do the trick. PSchrauber - Petcock has been overhauled and given a clean bill oh health.Rubber has been inspected and is fine.I might take off carby again and ensure ALL airways are clean and free from gunk. Hewson - Think this might be the way to go. Can anyone give me a quick run down of the way to gain access to the Crankcase seals and how difficult/easy the job is. I do have a fairly well equipped garage and have a fairly good background in motorcyles engines ( I actually used to work for Weslakes building 500cc speedway engines). Many thanks once again for your input. Micknal Quote Link to comment Share on other sites More sharing options...
pschrauber Posted November 22, 2011 Report Share Posted November 22, 2011 To replace the oil seals of the crank is a lot of work: left side: - take of rear brake lever, (might be in the way), - take off rotor and clutch arm cover, - not really necessary but in case you wont get too dirty, take off chain - take off rotor, - take off ignition plate, (mark position befor you do so). - there you are. right side: - drain clutch oil, - take off gear lever, - take of clutch cover, - deassemble clutch, - for better clearance, the internal gear lever to the jack, (I have no experience to the M80 engine) - demount primary chain tensioner, - take off clutch and flywheel and primary chain, - there you are. It's good to have an engine manual for all the spec's and special tools, (clutch springs, gear puller and clutch holder) you need. A lot of work, so I would first look through all the other possibilities befor I personal would start replacing the here. Another place to look at, - even if you have a good spark -, the points and the condensator just in case. Quote Link to comment Share on other sites More sharing options...
hewson Posted November 22, 2011 Report Share Posted November 22, 2011 If you have a magneto puller , a windy gun (or clutch holder) to undo the clutch centre nut and a hour to spare , its a easy job , no need to split crank cases , both side seals are held in with a holder that bolts to the crank cases , maybe try the mag side first . Flywheel magneto puller ( what ever you want to call it ) cost about Quote Link to comment Share on other sites More sharing options...
micknal Posted November 24, 2011 Author Report Share Posted November 24, 2011 Just an up date. Have managed to remove oil seal on mag side. Seal feels quite hard, not soft and pliable. Have ordered new seals today and hope to tackle clutch/flywheel side over the weekend. Micknal Quote Link to comment Share on other sites More sharing options...
micknal Posted December 1, 2011 Author Report Share Posted December 1, 2011 Gents Oil seals have now been replaced. Still will not start. Squirted fuel down plug hole - fired straight away. Think this is now pointing to a carby problem so going to remove and ensure all is well inside. Anything particular to check within ???? Micknal Quote Link to comment Share on other sites More sharing options...
pschrauber Posted December 1, 2011 Report Share Posted December 1, 2011 Gents Oil seals have now been replaced. Still will not start. Squirted fuel down plug hole - fired straight away. Think this is now pointing to a carby problem so going to remove and ensure all is well inside. Anything particular to check within ???? Micknal You might check all the small ducts, and brass tubes. They have to be free and not clogged by gas gum or any other debris, also jets can be covered by gas gum too. A very good carb cleaner, a ultra sonic cleaning can be very helpful Carb with around 15 year old gas gum and residues. Quote Link to comment Share on other sites More sharing options...
micknal Posted December 7, 2011 Author Report Share Posted December 7, 2011 IT LIVES !!! After cleaning out the carby once again ( there was still some gunk in the airways) and refitting the engine burst into life - just !! It didn't sound very happy and died after a few seconds but in fired ok. Can you suggest to me what I need to do now to get running sweeetly. Many thanks Micknal Quote Link to comment Share on other sites More sharing options...
sherpa325 Posted December 7, 2011 Report Share Posted December 7, 2011 Try putting a new condenser in the bike. Faulty condensers will still give a spark when turning the motor over with the kickstart but can breakdown under load. They are relatively cheap and you an eliminate that area as a problem. I put one off a lawnmower once as a stopgap measure for a friend and it worked fine. Cheers Greg Quote Link to comment Share on other sites More sharing options...
micknal Posted December 8, 2011 Author Report Share Posted December 8, 2011 Thanks for that Greg. Take it that any condensor could be utilised then ? ? ? Micknal Quote Link to comment Share on other sites More sharing options...
sherpa325 Posted December 9, 2011 Report Share Posted December 9, 2011 I don't know for sure, but I don't think they are critical in terms of size as long as they are in good operational condition. Quote Link to comment Share on other sites More sharing options...
b40rt Posted December 9, 2011 Report Share Posted December 9, 2011 I get VW condensors from Euro Car Parts, has a bracket for easy mounting and 2 connectors whick makes it easy to connect up. I will get the part no if your interested. Quote Link to comment Share on other sites More sharing options...
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