Britannia Mk1 rebuild troubles

[nick61]

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

[Charles uk]

Nick have a search on "twin spark coils" or something like that, there were a series of posts on this topic a few months ago

[nick61]

Thanks Charles. I did the search and found several references but none of the articles seemed to meet with much success.

One point of note: the guy who tried re-winding his own coils was using more primary turns than my original (well I think it's original, and given that no-one seems to have replacements I doubt it can be anything else). My primary only had 150 turns of cotton covered and enamelled 22SWG wire. His might be different as I think he had Wico ignition rather than Villiers, but I doubt that affects the primary much. Of course as he discovered the secondary will be a b**** with such fine wire, even so I'll probably give it a try if all else fails.

[Collector Inspector]

Thanks for the PM Nick that got you started with us,

Just a thort about coils in that I have had much success with single pole soldered to two HT leads in the past? Two Ht leads from the central point Aye.

Now wait for Old Salts to to howl me down .............Works with Brits with Wipac.

but I am "An Old Salt As Well" so this may get interesting.

Also Australian Riptide twins with Wipac/Pacey ignition................

These old coils can actually fire two plugs from one winding not a problem!

I have one Britt just like that...........one coil common with two leads soldered to it and standard point/condenser set up.

3800 - 4000 Rpm, smooth as an a Elto!

B

[Monty Stubble]

Who have you tried for coils as I picked up a NOS one about a month ago.

If no luck I might be able to help. I've got a few Villiers bits which you might want.

Chris

[Monty Stubble]

btw - the correct plug is a Champion No. 17 or equivalent.

Also I have been quoted £9 for new piston rings from Thorntons.

C

[nick61]

Thanks guys,

That gives me some confidence that the single coil should work. It still seems an inelegant solution to me, so I may still try to make one - good excuse to finally fix the coil winder!

It does however mean I can't blame the coil for the failure, that only seems to leave the flywheel. Any ideas on re-magnetising that? I did see an article on the web once, but although the principle - hefty electromagnet running from an accumulator (car 'battery') - was clear, the configuration for setting the flywheel v the magnet was not. I did have the chrome re-done outside, but I like to do as much as possible in-house, so I'm not really looking for a repairer unless all else fails.

Thanks for confirming the plug. I had noticed the markings in some of the pictures in this forum, but that was a much later model. The only problem is I can't see Champion '17' listed anywhere. Is it the same as Champion 'K17'? There's a guy selling some on ebay; a bit pricey for 1 but he's got 4 and might do a deal....

Cheers,
Nick

[Keith.P]

For old type spark plugs try

http://www.gsparkplug.com/shop/champion-17.html

[Monty Stubble]

If all else fails I have got a spare magnetized flywheel.

CJ