Britannia Mk1 rebuild troubles
Posted: Fri Jun 10, 2011 8:32 am
Hi,
I've just joined the group, and like most newbies I'm looking for some help!
I have a Mk1 (I presume given that unlike the ones you show it has Villiers ignition). It seems it may have been a display model with chromed gearcase, shaft and nuts. There's no date on it as such, but the ignition plate has a Villiers date of 1943 and a stamp BMB I562 (letter I not number 1) the crankcase is stamped OLR 8131B on the arm that carries the throttle control.
It was in a farily bad way when I got it, the cylinder to crankcase studs had mostly stripped in the crankcase so I replaced with helicoiled 7mm (9/32 BSCy is just top outrageous a price for the helicoils) using stainless A2 for the studs. Much else is now stainless including the prop shaft, bracket hinge, all nuts (mostly home made including the flywheel retainer) etc, etc. You get the idea! Well of course now the rebuild is finished it won't start! A Villiers dealer persuaded me to use a new single pick-off coil (the doubles don't seem to be avilable, though I may end up re-winding my own) and connect both outputs together. If anything this is worse. There's clearly fuel, and with the plugs out a spark(no idea what the correct plugs are, but it shouldn't stop it running), but turning over only produces a few wiffs of smoke and no running. I guess the spark is too weak under compression - which seems good (I had to make a new piston ring - slice off old brake caliper piston ground down to size).
The only idea I've got left is to re-magnetise the flywheel, so I hoping someone's got some other ideas, or perhaps tips on how I can fix the flywheel myself.
Cheers,
Nick
I've just joined the group, and like most newbies I'm looking for some help!
I have a Mk1 (I presume given that unlike the ones you show it has Villiers ignition). It seems it may have been a display model with chromed gearcase, shaft and nuts. There's no date on it as such, but the ignition plate has a Villiers date of 1943 and a stamp BMB I562 (letter I not number 1) the crankcase is stamped OLR 8131B on the arm that carries the throttle control.
It was in a farily bad way when I got it, the cylinder to crankcase studs had mostly stripped in the crankcase so I replaced with helicoiled 7mm (9/32 BSCy is just top outrageous a price for the helicoils) using stainless A2 for the studs. Much else is now stainless including the prop shaft, bracket hinge, all nuts (mostly home made including the flywheel retainer) etc, etc. You get the idea! Well of course now the rebuild is finished it won't start! A Villiers dealer persuaded me to use a new single pick-off coil (the doubles don't seem to be avilable, though I may end up re-winding my own) and connect both outputs together. If anything this is worse. There's clearly fuel, and with the plugs out a spark(no idea what the correct plugs are, but it shouldn't stop it running), but turning over only produces a few wiffs of smoke and no running. I guess the spark is too weak under compression - which seems good (I had to make a new piston ring - slice off old brake caliper piston ground down to size).
The only idea I've got left is to re-magnetise the flywheel, so I hoping someone's got some other ideas, or perhaps tips on how I can fix the flywheel myself.
Cheers,
Nick