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Topics - john11668

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1
British Bikes / Triumph model P info needed
« on: April 17, 2023, 10:59:16 AM »
Hi  Folks !
Its a long time since I have been here  so please excuse my absence
Looking for help with a Triumph model P

Was trying to set the timing after my mate had fitted a refurbished Mag dyno ( He  was turning the engine while I looked for TDC on compression stroke)
Book we have does not have much detail so was going for 7mm before TDC on compression stroke with full advance . (points gap set at  .012)
Was surprised to see that  engine appears to run backwards ( clockwise as viewed from the contact breaker side )   Is this Correct??

The reason for the mag upgrade was due to its history .  Almost impossible to start.  When delivered the  seller started it with some difficulty,  and my mate has not managed to start it since.

We have exhausted all the usual possibilities  Carb. plug , mag, before delving deeper,   ie before  stripping the head and Cylinder so next step would be to test compression. Can anyone advise what figure is reasonable for such a longstroke sidevalve??
And then of course if   problem was lack of compression  are spares available  and where to search.

Many thanks     John



2
British Bikes / B31 spluttering and flashing back through carb
« on: October 23, 2019, 11:20:25 PM »
This is about the bike we converted to electric start, which for about a year has run sweetly with no significant problems. http://classicmotorcycleforum.com/index.php?topic=5722.msg26756#msg26756

Recently it started spluttering while out on a run and had to be recovered to the workshop .
We found that the clamp retaining the dynamo and Mag  had worked  loose allowing the dynamo to move,  and we wondered if the timing might have jumped a tooth and set about checking.

It asks for 7/16” before TDC at  full advance .   We found it at about 1.7” so adjusted back to  7/16".  It then would not start at all.  Changed the plug and got it to fire but was still running rough and popping back through the carb.  No matter where we set the advance lever , it still backfired when we eased the choke back to normal running position.
Then tried at 7/16” btdc with full retard,  (on the basis that we could advance it on the lever to find a sweet spot.)   We were unable to find a point where it would run without choke, yet without popping and flashing back through the carb.  Full advance takes it to about the 1.7” btdc  figure , which is where we found it.

Turning to carburettor we  tried all the needle positions of the carb ( Amal 928) and no improvement. Just a bit more smoke at highest needle position
Even tried a new carb which does  exactly  the same .   I know the proper carb should be Amal 276  but the bike had always had this one and it has run well since we recommissioned it .

We have checked compression (115-120 psi  cranking).   We have tried a couple of new plugs too.  Contact breaker points  gap is 0.012” 
Despondency is starting to take hold  of us .
Can anyone point us in the right direction.  If we are going wrong we just cant see where.
Any assistance will be much appreciated 

John

3
British Bikes / 12v conversion
« on: December 01, 2018, 05:35:52 PM »
Hi folks
Following on from this thread   http://classicmotorcycleforum.com/index.php?topic=5722.15   we are in the process of fitting a 12 v conversion.

Have fitted a new field coil and armature (12 v type) and a solid state regulator. https://www.ebay.co.uk/itm/Positive-earth-solid-state-DC-dynamo-12v-regulator-rectifier-Lucas-E3L-E3H/401549799839?hash=item5d7e3bb19f:g:mRwAAOSwrU1bG5ly:rk:1:pf:0

Trying to follow the instructions for the regulator which has wires for field and armature (yellow and green),  neg and positive (black and red)

The instructions are not clear on where to send the regulated output into the loom. The Bikes own wiring diagram shows a purple wire  to the ammeter with a brown returning to charge the  battery,  but we seem to have  yellow /green  and orange/ white . Tried both ways round with a protective fuse in place but the horn sounds so we are clearly bypassing the horn button. Otherwise confused !

My experience of old bikes  has been unfortunate as the wiring codes never seem to correspond with the book. Any help here will be appreciated 

4
British Bikes / Tiger cub rectifier .
« on: September 06, 2018, 04:38:43 PM »
Cub is not charging and we believe that the rectifier is the problem .   9.5 volts easily out of the alternator cables.  Nothing beyond the rectifier.
Got a replacement But while I am generally  ok with electrics this one has got be beaten. We were recommended one by the local auto electrician.
Pics of old and new attached  but there are so many options for connections on the new one, and I just cant get my head around the directions of the diodes

Any advice would be welcome 

5
British Bikes / Cush drive , necessary or not
« on: May 02, 2018, 10:07:49 PM »
Hi folks
I understand that on the later B31 when an alternator was fitted , the cush drive was dispensed with!
Can this be done generally.  Would it be a problem if there was no cush drive??

The main reason for the question is that we are looking to put an electric start on a tin chaincase bike . We are looking at an  external pulley wheel with sealed sprag and we intend to try and fit a large (say 80T ) timing pulley.  This will be a much simpler task if we don't have to contend with maintaining the cush drive function.

Would be happy to here from anyone who has tried this or knows any cause, or just impediment why this may not be done.
In the search function I saw electric start  described as "wimpy".   Not for a 70 year old who is 8 stone wet through it isnt !   ;)

6
British Bikes / BSA Maroon Paint code
« on: February 26, 2017, 05:29:31 PM »
Hi again all

Does anyone know the paint code for the maroon used on BSA motorcycles such as B31 in 1954.
I just want to touch up a few items

7
British Bikes / B31 Values
« on: December 10, 2016, 06:13:28 PM »
Hi  Folks
Am new to the forum and assisting a friend with the purchase of a B31.
It is not a Barn find really,  but has been stored for just over ten years  in a barn. It is the maroon colour!
Carefully kept covered with motorcycle cover and dust sheets , looks pretty  clean  and a good polish would  make it look good again.
It seems it was built by a well known restorer , but not from a single bike  hence when registered it was given an age related plate. The "log book" is the V5 style

It is said to have won top award  at a national show,  yet clearly some work will be required to bring it back to concourse condition.
I presume the battery is shot,  not sure about tyres , and of course all fluids will need replacing . And fuel will be gummy by now of course!
No reason to suspect that it wont start with a day or so of work.

I can of course look around at the asking prices  on the net but my question is as follows :-
How would  valuation differ between an original bike restored to concourse  condition, and one which is rebuilt to concourse condition from a couple of donor machines.

I am reluctant to post pictures  at this stage for fear of identifying the location, and risking gazumping. but will be happy to do so when a deal is agreed

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