[scott596]

Jonathan, it is the cam ring that has the two slots in, the 4mm slot is for the A&R cable and the 10mm slot limits the amount that the cam ring can move. The slipring is part of the armature and has the brass segments that line up with the HT pickups. Alan. scottworkshop@hotmail.co.uk

[scott596]

Have a look at the top rear crankcase holes. Alan Noakes.

[scott596]

Eric, my Birmingham Scott that I have had from new has never had any numbers on the gearbox. Alan Noakes. scottworkshop@hotmail.co.uk

[scott596]

Such a shame that Scott men are stuck into a 1930s time warp and cannot understand how other petroil lubricated two strokes work, the system used to convert a Scott to run on petroil is the same as you will find on, Villiers, Bantams, Arrows, Yamahas etc, and I have to say I would never ever go back to a pumped system. I would like to concentrate on Steves problem, this might well be down to an air leak. I did have correspondence with Steve about my petroil system and did explain that he would have to experiment with his mixture if he converted his engine, at the time I thought he would be using a standard Scott carburettor so richening the whole range should have coped with the use of petroil, now that I have reread this thread I realise that Steve is trying to use a 32mm bore carburettor, the difference between a 1 1/16″ bore and a 32mm bore is quite considerable and the drop in air speed would have to be compensated for by using really big jets, the other problem Scotts have is that when the inlet port opens, the whole dead space around both cylinders has to come down to below atmospheric before any air movement takes place through the carb and at cranking speed this is not helped by using a big carburettor. Normally you would only consider using this size carburettor if you had carried out porting mods and filled up the the dead inlet area and even then starting from cold will be harder. On my own Scott which is probably more highly modified than any other, I have a 1 3/16″ Amal TT carb which is smaller than Steves carb, while I cannot remember all the jet sizes I do know that it has a 109 needle jet and a 600 main jet, so quite a big jump in jet size for a carb only 1/8″ larger than standard. My own starting proceedure from cold is to flood the remote float bowl untill fuel is pouring out kick 4/5 times then flood it again it usually catches on one cylinder and I have to pump the throttle before it chimes in on both cylinders, so still showing every sign of being weak at start up. As I said the problem might well be an air leak but I would be inclined to use a 27/28mm carb and start off very rich and then weaken off as necessary. Alan Noakes. scottworkshop@hotmail.co.uk

[scott596]

About eight years ago when I used to attend the south London section club nights, a chap turned up and told us that he was Gordons son he showed us the light weight rear suspension units that Gordon had made, he said that he was rebuilding his fathers clubman special, I have no idea what has happened since. Alan Noakes. scottworkshop@hotmail.co.uk

[scott596]

Please be aware a Scott engine cannot run on petroil without proper modification, anything with metal glands needs a neat oil feed or at the least a crossover system, even if you fit oil seals the engine still needs to be modified before it will run reliably on petroil. Alan Noakes. scottworkshop@hotmail.co.uk

[scott596]

Hi Kev, make sure that you start off with a Birmingham/coil ignition type gear lever as the magneto type is different, see attached photo, the bends on the lever can be tightened up to clear the pump and this will shorten the length as well. If you are using one of my reduction units they are eccentric and can position the pump further forward. Alan Noakes. scottworkshop.co.uk

[scott596]

Nick, when the lower nut is slackened the float chamber can be moved forward and back, this raises and lowers the float level in relation to the carburettor, while this can affect the working mixture it might also slow down the leakage. Alan Noakes. scottworkshop@hotmail.co.uk

[scott596]

Hi Charlie the lines on my new 64 Brum were approx 4mm for the thicker one and 1.5mm for the thin one all hand painted. Alan Noakes. scottworkshop@hotmail.co.uk

[scott596]

Hi Eric as far as I know the early long frame flyers that had the straight back crankcase used a different shaped undertray that had a tapering section into the bottom of the crankcase, I think the gearbox was set back a bit further, wether the rear mounts were any further back I don`t remember but as the rear clamps were moveable this would not be a problem, but the early trays did not have the large hollow bolts at the back like the post war/ Brum trays, so if you see a tray with 3/8″ holes at the back it wont be any good for a Brum Scott. Alan Noakes. scottworkshop@hotmail.co.uk

[scott596]

I actually make portable roller starters for home or paddock use if anyone is interested. Alan Noakes. scottworkshop@hotmail.co.uk

[scott596]

Hi David I have some photos here of an undershield etc. that I made a while ago, not sure if I retained the drawings but will have a look, PS. I still have a front shield available. Alan Noakes. scottworkshop@hotmail.co.uk

[scott596]

Hi David, the answer to your question is that Scotts weren`t interested in reality all they were interested in was having something that could improve sales and the brake probably looked better with rear facing brake levers so that was the way it came out of the works, the whole question of motorcycle brakes is of one maker copying another and not even questioning the technology because the performance was adequate for the time. Car makers on the other hand knew that their motorcycle type brakes were useless in the 1920s and needed a serious upgrade hence the adoption of servo type brakes where the shoes could centralise themselves. The best advice for motorcycle brakes is to centralise the brakeplate before locking up the spindle but this is impossible to do in most cases as 9 times out of 10 the brakeplate has its centre hole exactly the same size as the spindle and this stops the shoes moving on to centre to give best performance, so my advice is apart from turning brakeplates around, bore out the spindle hole in the brakeplate and allow the shoes to centralise properly, without doing this you might only have a small percentage of the brake lining touching the drum. Alan Noakes. scottworkshop@hotmail.co.uk

[scott596]

Hi the reason is that if the locking ring ever touched any part of the backplate while the wheel was turning it could undo itself if fitted on the right but would only try to do up when fitted on the left. Alan Noakes. scottworkshop@hotmail.co.uk

[scott596]

I have posted a similar reply to this question before, there is a reason why brake levers should point forward and not backwards as Scotts supplied them, and the reason is this, although the brake cam lifts both shoes the edge of the cam nearest the spindle will lift its shoe slightly more than the edge of the cam further from the spindle lifts its shoe, so the brake shoe nearest the spindle should be the leading shoe, this can only happen if the brake levers are pointing forward, if you copy Scotts original design you will be putting all your effort into braking with the trailing shoe. Having said all this the Shipley 6″ front brake is entirely let down by weak shoes and backplates that just distort when applied. Over the years owners have also unjustly blamed the 2 into 1 cable junction box for the poor brake performance, this has nothing to do with it and is no different to the Royal Enfield twin cable lever fitted to Birmingham Scotts, on both types 1″ of cable movement at the handlebar will lift both brake levers by 1″ , the Vincent system is 2 to 1 ratio, 1″ of cable movement on the handlebar lever will only move the brake levers 1/2″. If anyone decides to alter their brake levers to forward facing please just change the backplates and not the whole wheel as the threaded ring locking the bearing should always be on the left of the machine. Alan Noakes. scottworkshop@hotmail.co.uk

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