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June 23, 2013
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The inner side id of the cam is slightly smaller than that of the outer. The fixing screw (normally a cheese head) sits inside the outer face of the cam with a small spring washer under it.
When replacing the cam, I find it easier if I hold the woodruff just key proud using a suitable drift (instrument screwdriver, etc) or often the cam just pushes the key down into the shaft. Put the cam over the drift first, then introduce them at the same time. Lookout for the tiny key jumping out!
December 6, 2016
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Thanks for the tip.
No spring washer and the screw/bolt isn't a cheese head. I there a recommended dealer who can supply these parts?
Alan
December 6, 2016
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Sorry, its just dawned on me that the bolt/washer/cam are actually engine parts, not ignition parts so I might be able to get them from one of the usual parts suppliers, Draganfly, Bournemouth Bantams etc.
January 9, 2013
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hi chaps i had some cut last week so if you get stuk let me know
December 6, 2016
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Thanks for the offer. I will have a fiddle over next couple of weeks and let you know. Im not sure if I will need the cam, probably just the screw, flat washer and locking washer. Do you have these? Alan
January 9, 2013
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yes Alan scew flat & lock washer but only 4 flat washers cut for me
December 6, 2016
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Thanks. Sent you a PM. Alan
December 6, 2016
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Used my new digital vernier for first time yeaterday. Surprised to find reading for rear spindle was .40 inch/11mm. I believe this is 7/16 when converted. I was expecting 1/2 inch.
Strange.
December 6, 2016
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Sorted out points cam today and it now seems to run fine. Thanks to all who assisted me in resolving this.
But its not all good news. I have an oil leak from top of crankcase, I can see it bubbling when the engine is running. I dont know how serious this is but hopefully someone will tell me it isnt!
I assume its gearbox oil, so wont affect the running of the engine so all I need to do is keep topping up the gearbox- correct?
If it can be run like this, but is it fixable?
Really hope it isnt serious, I need to get it on the road this year, almost 18 months since I got go and its been one thing after another wrong since then!
Alan
December 6, 2016
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Heres n image relevant to to my last post.
Alan
June 23, 2013
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I doubt it's gearbox if it's coming from the top - the gearbox should be neither full, nor pressurised, so no oil from it should be up there! Maybe, if it's around the cylinder base, you have a blow from the base gasket, if not I would suspect a damaged joint in the crankcase halves, forward of the g/box area.
Perhaps a pic of the leak when the bike is running would help?
December 6, 2016
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The image I provided was taken with the engine running. Its very clean oil which made me suspect the gearbox. Where else could clean oil be coming from?
November 16, 2011
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Nothing to worry about Alan, if it`s only that one area of crankcase sealing faulty,ie top of gearbox. You can wipe with thinners-soaked rag and work some petrol-resistant sealant into the join. Soak thinners rag in water before binning(self combustion safety issue).
Carb flooding(tickler) can be to blame.
December 6, 2016
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Thanks for the reassurance.
I think it must be gearbox oil, just why its coming out of the top of the crankcase I have no idea. All I can think is theres too much oil in there.
When you mention carb tickler do you mean dripping fuel could have dissolved the original sealant?
Is there a fuel resistant sealant you to recommend please?
Alan
November 16, 2011
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Seeing you`ve had it running, we`ll put "gearbox pressurisation due to leaking crankcase from the flywheel area", on the back-burner, and assume it`s just centrifugal force flinging oil off the gears and some`s finding its way through a gap at the top of the crankcases.
Yes petrol is a solvent and will attack certain sealants. I chop and change between sealants, some silicone ones are not petrol resistant, but a good one will hopefully do the job...it should state fuel-resistant on the tube.I`ll check the tubes I have later today and get back to you. I knew a top IOM TT engine tuner(Robin Church) from the 2-stroke era, he did some carb mods for a road bike for me, he went through a port into a water jacket and he repaired it with Araldite! Modified 350LC clocked at 160mph, the Araldite held well against water pressure and fuel.
Worth checking your gearbox oil level and also have a sniff of it to see if any petroil mix has found its way through the join between engine and gearbox to dilute the oil. Probably unlikely because by the same token, the engine could be drawing in gearbox oil and burning it via such a badly sealing joint....but I`ve seen some odd things with Bantams, so anything is possible.
September 3, 2012
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You may find a clue in the colour of the oil.
I have a similar problem with one of mine, clean oil bubbles out from the crankcase joint just behind the barrel. In my case I know its from the petroil mixture as it is coloured red. The bike doesn't want to rev up properly so I am assuming there is a problem there that may be causing it. I won't know for sure until I strip it.
I'm not a complete idiot ............................................ some parts are missing.
December 6, 2016
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Why would the oil turn red when mixed with the petrol, are you using a red coloured 2 stroke oil?
Oil seemed pretty viscous so not obviously mixed.
Exhaust didn't seem too smokey but not sure I would be able to tell the difference. Cetainly not pushing out clouds of smoke and didn't smell oily.
Alan
September 3, 2012
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Most self mixing two stroke oil is coloured, mine happens to be red, and although it is mixed with petrol in the tank, some of it separates out during use in the engine, otherwise it couldn't do it's job.
When you strip a Bantam engine that has been running on a proper petroil mixture, you will find that the crank, bearings, flywheels and the crankcase interior should all be coated in oil.
I'm not a complete idiot ............................................ some parts are missing.
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