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D1 engine running - couple of questions
Second Gear User
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September 22, 2019
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October 9, 2019 - 5:40 pm
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Well after 35 or so years, I rigged up my engine on a workmate and kicked it over. It started second kick! (video below all being well).

I haven't done much to it apart from new plug, condensor and cleaning up the coil wiring, and replacing piston rings.

So the good news is that the engine runs. It's very encouraging to be honest - gives me an incentive to carry on getting the bike back on the road.

There are a couple of issues though, which are to be expected as the engine hasn't been rebuilt.

1) There was some clean oil appearing from under the drive sprocket. I assume this must be an oil seal needs replacing? 

2) I noticed oil dripping out of the carb when running. Not sure what this means - is this a sign of anything in particular eg rebore needed? I'm guessing some kind of exhausting through carb is occurring. 

If I have to strip down and rebuild with new seals and bearings I will, but don't want to jump to conclusions.


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Central France
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October 9, 2019 - 8:08 pm
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Well done - I am firmly of the 'if it ain't broke, don't fix it' school. That looks and sounds OK to me. I would be inclined to not worry too much over oil leaks (if they are not gushing) and get a few miles on it to see if anything else crops up. It depends on how much you intend to use it, I suppose.

1956 D3 running, lights to sort. 7 other bikes in the Barn, 6 runners (when I get time!) and a still in progress Morini 250

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October 9, 2019 - 10:29 pm
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Fantastic, Julian. Pop a coupla wheels on that and you're ready to go! All sounds good on video. I agree, run it for a while and see what else crops up but in the meantime , enjoy it! clap

'52 D1 direct lighting plunger, '58 Square Four (project), '59 D1 direct lighting plunger,  '59 Tiger Cub, '60 5TA,  '76 FS1-E

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October 10, 2019 - 6:08 am
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Thanks for the opinions on how it sounds, that's good news! I have actually slightly overfilled the gearbox and have now read that this can cause an oil leak through the clutch pin (makes sense). I'll drain some out and leave as is for now. Lots to be getting on with. I'd better get a silencer on or my neighbours will hate me.

Bolton, Greater Manchester
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October 11, 2019 - 9:24 pm
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Hi and well done on a fantastic video,

I also don't think you have any worries. I would say the majority of bantam's leak a little oil from the final drive oil seal, I know both mine do. If your engine isn't leaking from the clutch push rod ( although thats is a big gear box oil over-fill ). The only thing leaking from your carburettor would be a petrol/ 2-stroke oil mixture. I sometimes get an oily residue on my frame and mudguard, probably due to over-run when going down hill. maybe yours is due to running the engine without an exhaust perhaps.

Keep up the good work..... Nick

1950 BSA D1 Plunger   242 UYW

1966 BSA D7  LBF 62 D

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