Classic cars forum & vehicle restoration.

buzzy bee · Joined: 23 Nov 2007 Posts: 3382 Location: South Cheshire

Hi

Just fiddling with one of the old BSA's, the D1, hasn't run for many a year. I put new fuel in after draining down, got a great spark, and it starts, but only Just. It doesn't rev at all, I mean the throttle does nothing, even if you pull the cable by hand.

I thought maybe the exhaust is blocked up, the float seems to be fine, it is floating. Had the carb in pieces and couldn't see anything obvious.

The other strange thing is the air filter is getting very wet, took that off, and whilst running it is kicking hall of a lot of petrol out the air filter end instead of in to the engine?

Had a play with the timing, doesn't make an ounce of difference.

Any ideas?

Cheers

Dave

welder · Joined: 26 Nov 2007 Posts: 265 Location: North Warwickshire

Dave, you may find that the crankshaft outer seals have dried and hardened through standing and are now allowing/drawing air which would present the symptoms you describe.

The proper cure is an engine strip and crank seal change but there's an old trick you could try. Fill the crankcase with petrol and leave overnight, then drain using the brass plug at the base of the engine. Petrol often softens old, dry seals, rendering them functional once again.

Good luck!

Ian

the fly · Joined: 11 Jul 2008 Posts: 95

Hello Buzzy try removing the silencer they often block upthe little flat jobs more so you cant dismantle the early ones . i in the past have set them on fire to clean them out plating was not an ishue in those days .Also remove exhaust pipe and check the port in the cylinder i have known them to block up with hard carbon . Bantam flywheel mags [wico ]are trouble makers a big spark is not always a good one it may pay to get mag tested if all else fails thats if you can find anyone with the means to test it . when ok bantams are a nice little machine have better wheel bearings than most lightweights of that era and perform well. Regards The Fly

Nic Jarman · Posted: Wed Feb 25, 2009 11:18 pm Post subject:

An easy way to see if it is spark related is to hook up a battery and disconect the mag wire. I did this to my old Enfield flying flea worked a treat.

baconsdozen · Joined: 03 Dec 2007 Posts: 1119 Location: Under the car.

I'd agree with the dried out seals idea.It wont do any harm to mix some fuel and two stroke oil abot 50/50 and spray it in the intake port.Sometimes when these engines have stood for years they end up with air leaks all over the place.