Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - john.k

Pages: 1 ... 19 20 [21] 22 23 ... 40
301
British Bikes / Re: Excelsior Universal 125cc - Rear Plunger
« on: May 06, 2019, 12:07:59 PM »
Is the springbox saveable?...What about the endcaps?...........the rod is easily replaced ,remaking the plunger unit ,a fair job of fabrication and machining.

302
Identify these bikes! / Re: Barr and Stroud mystery bike
« on: May 06, 2019, 07:06:46 AM »
There is a more interesting sleeve valve called the "Fischer ...Magic -crescent valve".........manufactured in Zurich from 1908 to 1914.......invented by watchmaker  Martin Fischer............produced .apparently by a "Turicum Co"............there is one example in the Zurich transport museum,and also a cutaway salesmans sample.......The valve was in two halves (of a liner),each reciprocating independently.............200-400 cars made ,before war work became much more profitable.

303
Identify these bikes! / Re: Barr and Stroud mystery bike
« on: May 03, 2019, 09:02:59 AM »
There was a B&S powered bike for sale about 10 years ago,IIRC,it was locally made ,and for sale on either ebay or just bikes.I think it was a 350,and the price was very high for what it was.

304
British Bikes / Re: Correct Ignition Position
« on: April 26, 2019, 01:44:41 AM »
Its usually pretty easy to tell where a low powered motor pulls best,and run with that advance.........I suspect you have probably set the timing well before TDC,and are getting plenty of advance..............a motor on full retard generally has no power ,and wont rev if you snap open the throttle................the biggest risk is excessive advance with high octane fuel.....no knocking,but enough extra load on the engine to break something.

305
British Bikes / Re: Stops When Hot
« on: April 26, 2019, 01:37:29 AM »
Heat does sound right....on  along downhill with throttle closed,no air or fuel to cool carb..................a lot of early SV s had the carby on a long intake pipe......maybe a good reason why,although it seems the pipe is needed to clear a magdyno.

306
British Bikes / Re: Excelsior Universal 125cc - Rear Plunger
« on: April 17, 2019, 02:03:56 AM »
the picture of the dismantled frame is in Sheldons EMU.......as a 1954 Excelsior Universal..............looking at the pic,I suspect the spring seat is threaded to the rod,and possibly there is a locknut.................however ,from a constructional point of view ,it would be also possible to make the rod two diameter ,and have the spring seat retained by the step between the two diameters......this method needs no thread,but has certain disadvantages...............summing up the evidence..........i would expect the central rod is "jumped up" and the increased diameter threaded for the spring seat.......the spring seat is clearly visible as a discrete unit ,secured to the central rod .

307
British Bikes / Re: Dunelt T S/A facecam
« on: April 16, 2019, 06:23:53 AM »
from what Ive seen of bits and pieces of engines ,the cam setup was not adequately lubricated ,and didnt last long in use.....but I havent seen a motor in near 50 years now.................all the oldtimers who had massive collections of interesting bike bits are gone...............sadly a local man with a massive collection passed last year ,and complete bikes and basket cases were sold off,but the huge collection of miscellaneous parts was mostly scrapped...........no one has the space to store this stuff any more....Not here anyway.

308
British Bikes / Re: How to be idle
« on: April 16, 2019, 06:17:38 AM »
The simplest way to set idle is to hold engine speed as desired by the hand controll,then simply wind up the carb screw until the revs rise........you will also feel the spring pressure disappear as the slide is raised by the screw.......then nip up the locknut...............you should note ,some bikes are setup to die as the grip is closed ,because they dont have a magneto cutout,stopping button that works........so owners prefer the engine to stop if they should fall off.

309
British Bikes / Re: Excelsior Universal 125cc - Rear Plunger
« on: April 16, 2019, 06:13:24 AM »
The only pics I can find online are a 1954 Universal in pieces,and its clear the rods have a central spring boss added,probably threaded on..........so cutting the rod isnt a total problem,as its just a rod .........but from the pic I can see that nothing had to be cut to remove the units.........unfortunately the pics are not all that clear,but clear enough to see that my & Rex s description is substantially correct...............my suggestion now is to take the frame etc to someone who has mechanical experience and preferably old bike experience,and person will immediately see whats wrong,which I am beginning to suspect is weldmetal done by a bodger............the Pics are on Sheldons.

310
British Bikes / Re: Excelsior Universal 125cc - Rear Plunger
« on: April 15, 2019, 10:15:30 AM »
Rex is quite correct........the whole unit .rod and all should slide upwards through the top mount ,when the bottom bolt and top pinch bolt are out............you should be able to remove the whole plunger unit and rod in one piece,then when out,unscrew the end caps of the plunger unit to free the springs........................unless someone has welded the top mount and rod together...........then you must pray for a poor weld ,which can be broken after a bit of grinding............ian ,this unit is quite different to a Norton plunger,inside out ,as it were.

311
British Bikes / Re: Excelsior Universal 125cc - Rear Plunger
« on: April 15, 2019, 05:58:44 AM »
Isnt there a pinch bolt retaining the rod at the top mount?...isnt the bracket slotted to the hole ,so the rod can be released by opening out the slot with a chisel or tapered drift?...............IMHO,you need to free up the top mount,slide the rod upward enough to clear at the lower end,twist sideways ,and pull the rod down..............cutting the rod works for the immediate situation,but then you have one more part to find,or make..............

312
British Bikes / Re: Excelsior Universal 125cc - Rear Plunger
« on: April 10, 2019, 10:11:14 AM »
toss a coin.....the spring or the rod?.............Brexit or no brexit...........decisions can all be simplified by a coin toss.

313
British Bikes / Re: Excelsior frame number C1/326 - which model?
« on: April 10, 2019, 10:08:50 AM »
hey,Ive still got stuff I had in 1965.........still for sale ......more rust ,and the price has gone up.......considerably................................or as someone commented at a swap.......youve only got till 2040 to sell that stuff ,after that it will be worthless........yeah,.its a worry.

314
British Bikes / Re: Excelsior Universal 125cc - Rear Plunger
« on: April 08, 2019, 12:34:17 AM »
You will have to cut away the upper spring............that is what is preventing you from removing the unit............I would use the oxy,but a 4" angle grinder with a thin cutting disc should demolish the spring without marking the frame........I would not cut the rod,as it likely has a boss in the middle......IE is not a simple rod.......so making one might be a challenge ,or costly if you dont have a lathe.

315
British Bikes / Re: Excelsior Universal 125cc - Rear Plunger
« on: April 06, 2019, 12:08:35 AM »
His whole? problem is the external springs added by a previous bodger........the Excelsior unit should remove easily from the frame,the extra springs are preventing movement ..............there is a truism with british bikes .......smaller the bike,bigger the bodge.........................although the best bodge I have seen is a large torque converter filled with concrete to restore drive in a big tractor........now thats a bodge.

Pages: 1 ... 19 20 [21] 22 23 ... 40