Search for tasks. Type in a few keywords.

Wednesday 4 May 2016

Jobs I hadn't expected to do again (2)! Tappets revisited.

Adjustment... Method 2
The manual suggests that the tappets should both be adjusted at the same time, i.e. when the piston reaches tdc. and both valves are therefore fully closed. This does give a noisy setting, although it's the sound that I personally am used to.

 However I have been recommended a second method that should give a quieter setup.


  • Set piston at tdc
  • Rotate both adjusters to vertical, with the flats facing one another.
  • Engage gear and turn the motor backward using the wheel until the inlet just tightens up- ie doesnt open but is about to!
  • Adjust exhaust clearance
  • Turn motor forwards until exhaust just tightens up
  • Adjust inlet valve clearance


No real pictures for this- nothing much to show but I took advantage of the need to remove the tank again for cleaning in order to get better access and perform this readjustment. I found it was necessary to turn the motor a surprisingly long way before the relevant tappet tightened up. Maybe that shouldn't be surprising as virtually a whole  piston stroke is required. Of course I cant start it up and tell whether this method has worked until I fit the new fuel taps.

Note added later- Bike runs and seems much quieter- so will definitely be using this method from now on!

Jobs I hadn't expected to do - at all: Removing the rear wheel and fitting a new drive chain

Wheels and Rear Chain

The rear chain was correctly adjusted as regards slack midway between the sprockets- however it  could easily be pulled off the sprocket at the rear of the bike- this should simply be impossible and any slackness here can never be corrected by moving the wheel backwards and tensioning the chain between the sprockets. There seemed nothing for it but to renew the chain. I ordered a new B25 chain (5/8 x 1/4 100 links) as this was specified in the parts list and supplied for the B25 by a variety of manufacturers.

Problems! This chain simply wouldn't fit- I couldn't move the rear wheel forward far enough to install it. I tried removing the rear wheel entirely in the hope that I could attach the chain and then fiddle the wheel back in.
left side rear wheel- the spindle cannot be slid fully forward owing to a shoulder. This is as far as it will go and it wasn't enough to fit the new chain.
I removed the rear wheel- starting with the speedo drive on the right shown here and from which...

... I could unscrew the drive cable. 
This bike has a so-called quick release rear wheel. The rear spindle is in two parts and the wheel can be removed by unscrewing the right hand section leaving the left hand end in place. The right hand section can then be pulled out towards the right of the bike. The right-hand axle spacer and speedo drive unit should drop off as the spindle is withdrawn.  The wheel itself should then be able to move right and back to detach from the brake hub/sprocket unit and drop out leaving the brake plate, sprocket and hub unit attached to the left hand swinging arm. In theory this doesn't upset the wheel alignment, chain tension or brakes... great! Except that in my case it didn't work: The right hand spindle nut was loosened, but in my case the speedo drive unit was jammed onto the axle and so the axle couldn't be withdrawn towards the right as intended. Instead I had to remove the wheel entirely, including the brake hub/sprocket. I  unscrewed the torque arm from the sw arm and unfastened the left hand (brake plate retaining) spindle nut. In order to remove the rear wheel its a great idea to raise the bike by putting blocks under the centre stand.
Brake backplate on removed wheel.



Wheel spindle assembly, from the right- note fixed end with nut and tommy bar hole. Inboard of this comes the adjuster and  gap for the sw arm fork. There is a spacer inside the arm- which is a bit rusty and then the speedo drive itself which locks onto two driving slots in the rear wheel centre. Inside the wheel is a spacer shown here (note orientation- it will not fit the other way around, and the rest of the RHS spindle. This spindle screws inside the left hand "dummy axle" section which is consequently thicker as shown above. There is a second spacer on this thicker section that fits into the sprocket drum to close the oil seal. The threaded section on the left emerges through the brake backplate and sw arm left fork. Outside of the sw arm it carries the second wheel adjuster and a cap nut. This cap nut retains the brake plate but doesn't usually need to be removed to take the wheel off. It came off in this case only because I couldn't pull the axle out to the right of the wheel.

Close up of RHS speedo drive note orientation of spacer inside seedo drive.


Two shots showing how the composite rear axle fits into the sw arm forks. 
 However, even removing the wheel didn't allow me to fit the chain. I double checked the length and... oops! I hadn't realized that chain lengths specified in the catalogues include the removeable link- I hadn't counted this when I had checked my own chain and including it means that I require a 101 link chain! This is apparently specified for the Fleetstar as opposed to the Starfire (which does use a 100 link chain) although this fairly important fact isn't mentioned in either the '68 or '69 B25 parts lists and nor is it mentioned in the Fleetstar supplement... so who knew! Luckily the supplier was able to send an addition link to allow me to extend the chain. I show here a photograph of my original chain (lower) which has a cranked link inserted giving a total length of 101 rollers and presumably 100.5 links?? The new chain is shown above where the cranked link is clearly missing. Hopefully I will now be able to reassemble the bike!
Original chain (lower) and new chain (upper) Note cranked link and extra roller pin in the old chain.
Well the extra link duly arrived and I used a Sealey Chain breaker rivetter to remove the old and install the new (plus extra pin). This tool comes with its own instructions but those from Motion Pro for their equivalent tool are much better- you can find them here:
http://www.motionpro.com/images/documents/08-0058.I8-0058.pdf
The tool is identical.
This is the link in the new chain that needs to be removed and below is the new link and cranked  link that needs to be inserted to lengthen the chain by one pin

I used a Dremmel to grind around the pin to be removed to take off the "mushroom" flare that holds the pin in- this should make the pressing out easier


Assemble the link breaker using the right sized pressure pin as in the instructions- screw in the top bolt to press out the link which will... 
Fall out from the base of the chain

This is the links separated and the new ones with the soft link to be fitted instead



Here soft link in position

and plate loosely installed over the top

The rivetter is reassembled using the grooved and holed plates to press the top plate onto the soft link. I measured the width of most links as 0.6" and pressed the new plate on to a similar dimension..



Installed plate- soft link projects above the new plate so that...


It can be flared with the rivetter once the tool has been modified to substitute the anvils for the two plates.

Completed chain with new links rivetted in.

Both ends of the new chain now join-able with the split link.
 Once the chain was extended, I needed to lube it before installation. The one word/phrase missing from the pack when I got this chain was "O-ring" so I assumed that this is a somewhat old-fashioned chain lacking O-rings. This proved to be correct, but it does mean that lubrication is more crucial. The following is  a method for greasing non O-ring chains, it does no harm to O-ring type but I doubt it does that much good either. Before lubing the chain I cleaned off the transport grease using chain cleaner and a fluff-free rag.



In the old days this stuff was called "Linklyfe"... can't get it now, but this Putoline chain wax seems to be the same stuff.- Stick it on the stove to melt the grease- do this when no-one else is in and don't tell anyone. It can smell a bit- be careful to clean up any spills.

Molten and gloopy
 Carry the tin carefully back to the workshop- put some paper down! Tie a string through one end of the chain
Using the string lower the chain into molten grease, swirl gently and allow to remain immersed in the grease for at least 10 mins.

Bubbles will rise...

Lift out the chain using the string and hang it vertically to drip the excess grease back into the can- this will be messy- remember the newspapers... The grease will set on the chain fairly quickly and dripping will stop.

Add caption
 Having modified and now greased the chain I was able to install it easily- the two ends lined up beautifully on the sprocket.
Chain aligned on rear sprocket
Install cover plate and finally...

Fit split link with closed end facing the direction of movement in normal riding.
 The next problem is to set the wheel alignment. This really needs to be done a few times at each stage but at present- with the brake backplate not fully tightened I checked it anyway using a chain alignment gauge. This clips onto the rear sprocket and the guide rod should then run along parallel to the run of the chain- as here. I had by now cleaned the threads of the adjusters and their nuts so I could just nip them up to the adjusting plates to hold the wheel in this position.


I will recheck as I tighten all the bolts.  Finally I managed to get hold of an original B25 chainguard as this bike had a pattern part. The design underwent a change in 1969 so the guard that my bike should have was only made for a year. This is probably because the mountings (one at the front and one midway along the guard)  allowed too much vibration and so the darn thing always cracked. Consequently there are very few of those around, but you can still get the later type in which the rearmost mounting was moved right to the rear of the chain. This needs a new mounting hole (two actually) in the rear sw arm behind the shock absorber mounting. I drilled and tapped one hole to make sure that the guard would fit (it uses the same front mount).

The guard fitted well although I did need to bend it slightly to prevent the chain making contact at the front.




Decals

Well the bike is back together and running- it has some annoying habits- idle is too fast and won't slow down- I think the cable is too tight, The motor keeps cutting out- I think its because I'm running it with barely any fuel at present, and the tappets are still too noisy- I will try the new method of adjusting them (details later)

At the moment I'm trying to tidy up its appearance so I'm stripping the nasty paint off the front wheel rim (I will try to bring the chrome back and respray if I cant... hopefully I can get a better finish) and trying to apply some fresh decals to the bike and failing! I haven't managed to get a clear description of all the decals this bike should have had. Certainly it seems from photographs and brochures that the non-Police Fleetstar had a white winged BSA logo on the tank and a "Fleetstar 250" decal on the battery cover and oil tank. I suspect there would have been a couple of piled arms as well as  warnings/notes as well but I haven't been able to find them described anywhere. There seems to have been a lot more on the US export bikes, but as most of these were only required for the US market I can't use them as a guide. I will keep checking but sending a query to the forum failed to proved any more enlightenment. I ordered these twotypes from eBay. The tank winged "BSA" decals were easy- peel and stick; the side panel "Fleetstar 250" were a different matter.
Tank decal- self-adhesive so a bit "blocky" Gold BSA on a transparent sticker

Self adhesive decal- but even more blocky than above as its lettering on a black background which isnt quite the same intensity as the paint colour- clear background decals are nicer.

NOTE to sellers of DECALS- There are (at least) three types of decal- peel and stick, water slide (a little like those RAF roundels that came with the  plastic plane kits we made as kids) and varnish stick They are not the same. The former may be called a sticker, the latter two transfers, but they are all decals. Why oh WHY would anyone even think of selling them without saying what type they are??? Yet everyone does! What's the matter with you all? - Put some basic information in the bloody ads for Heaven's sake!

The peel-off ones are easiest to use- but look worst! They are simple to recognise, removing the backing paper reveals a self-adhesive surface on the back of the design.
Self-adhesive (vinyl cut) decal. As it comes (upper) and partly peeled off (lower). Note sticky surface on the back of the decal 
Apart from the peel-off sticker type, fixing the other two is not straight forward- and its not "easy" despite what it says in the listings. It needs instructions (which are always absent) and it needs practice; if they are the varnish-fixed type then you need to know to get the right stuff in before you try. Most descriptions of the method direct you to US varnish brands- The usual type are actually floor varnishes (eg Minway high gloss fast drying polyurethane varnish). I think there was a Johnson equivalent on sale in the UK (called Klear or Future?) but no longer- although it is available now repackaged for modellers in smaller amounts. I suspect virtually any polyurethane would do- but then you don't want to risk your decals trying any old varnish do you... ? I have just buggered two Fleetstar decals purely because of lack of information from the seller- and the fact that they were closed for half the normal working week and so weren't there to help when I needed them. ..  overall NOT a happy bunny at all.

Varnish-applied type- note the front and back mounting paper (above- as it comes) and below with part of the backing paper removed (front paper now down). 
Varnish-stick decals have two backing papers, peeling off the back one reveals a non-adhesive surface, the decal itself is still attached to the front sheet but it is upside down (see lower decal above).

Water slide decals- no picture sadly- Also have two backing papers, and when you remove the first you also find a non-adhesive surface - but in this case the the decal is uppermost- ie the right way up. It is usually still attached to a glossy backing paper on which it can slide when wet so it can be eased off the backing paper and onto a wetted paint surface..

... 24 hrs later, calmed down! Classic bikes of Cheshire did respond to my missive and offered an odd fixing process... I don't think they realised that the decals they sold are for varnish fixing. They offered a replacement but I had already sourced a cut vinyl self-adhesive replacement which is self adhesive and thus much easier- although not of course original at all. I fitted both decals but the side panel was looking a bit ropey so I resprayed that using black gloss Aldi metal protection paint first- covers really well and goes straight on over metal. Takes a couple of days to harden fully but very pleased with this- much better than Hammerite which I always preferred, but recently it seems to have an unacceptably low pigment content and takes ages to cover.

I also replaced the tank rack screws and fibre washers beneath each leg. I used smaller washers so that they didnt show beneath the legs. Lining up the screw heads gives a nice neat appearance.