I've just started building a 1967 BSA B40WD and was just after some info on anything in particular I should look out for with the '67 B40WD?
The thing is being built completely from pieces so this should be a long and interesting build I've just finished going through and getting most of the parts for the motor together and sorted and have new bearings and gaskets on the way.
Anyway, if anyone has has experience with the B40 WD it would be great to hear about it.
Hi blackie i had one last year, great bikes mine was a 1967 ex-RAF Military police bike. some one had painted it red a long time ago but yuo could still see the duck egg blue under the tank and on the wheel hubs. great run to ride
If it is in pieces the toss the big end bearing out & fit a B44 one with the 1/4" rollers. The Australian army specified the higher rated B50 needle roller big end which is great if your engine is running at blue smoke speeds. Then they specified 3 off road gears and a standard top so you have to valve bounce in 3rd in order to change into top without the engine boging down. Similarly when you change down you have to valve bounce the motor before you release the clutch or your filling will be catapulted out of your teeth. labouring the engine in top gear will cause the cage of the big end bearing to scuff on the outer race, eventually breaking up. If you are lucky it will drop into the sump so you can at least ride home. If you are not lucky it will hammer weld onto the outer race and seize . I had a box full, 73 in fact , con rods with cage hammer welded onto the outer races. I got them from Gladesville Motorcycles who had a contract to maintain the few remaining servicable B40's before they were replaced with Suzuki 400's and Honda Elsinore's.
The armed services ordered 490 ( or there abouts ) B 40's in three colours, green ( army ) grey (navy ) and blue ( airforce ). 228 were disposed of when Defence Stores were taken over by clvil servants and DAS cleaned out all of the obsolete stock hiding at the back of the warehouses before they sold the land to property developers. All of them were labeled " PROV UR " , provisional uneconomic repair or CERT UR , definate uneconomic repair. The only reason they became UR is the big ends were stuffed. I can account for around 60 of these bikes and each & every one eventually dropped the big end, so don't be fooled, your is stuffed, you just don't know it yet.
The external oil filter is a Britfilter and the replacement filters are available in the UK. Don't bother trying to use any other gaskets than Steves, his are the only ones that will stand up to service. It is a 6 Volt system, all other military specifications were 12 V. When you get around to fitting the carburettor which is slightly down draft on the Aust bikes make sure you fit the 1" spacer between the carb & head and make sure you fit an 18" long tube to the drain outlet or you will never get it to run reliably. Be very careful if you start it on the emergency setting because if you try & run the bike that way it will blow the battery big time. The cam is the ET type with a flat on the base circle so it stays open , then closes & reopens. Because the points cam is cantilevered on the ned of the valve cam any wear in the bush can cause the cam to bounce as the valves open & close thus giving you 3 sparks. If you are going to persist with the original ignition toss the points plate & fit the latter 6CA type as fitted to late models A 65's and mount the capacitor remote, near the coil . Also buy aftermarket A 65 points so you get a spare set which you can handily store on the points plate. Because the points are held open for 80% of the cycle, the rubbing block wears quickly so the gap will always be closing up. You can also fit a "normal" type A65 cam but if you do you can not use the emergency start facility.
Get a copy of Rupet Ratio and do the mod to the valve lifter as there is a 99% chance that the hole will be flogged oval and they leak a lot if they are.
Pull the cylinder studs and dress the crankcase mouth, they are never flat. When done put a small counter sink around the studs and fit the thinnest O rings you can find to stop oil running up the stud and leaking out from under the head nuts. Similarly dress the floor of the head where the rocker cover goes on, they are generally badly damaged from over tightening by DPO's trying to stop the oil leaks which will happen if you do not use Steves gaskets.
The brake drums are significantly harder than the normal BSA nikasil drums and can only be rotary ground. DO not let any idiot try and machine them no matter how space age he tells you his gear is, rotary ground or nothing.
The exhaust is very loud, that is normal. Apparently totally inaudible at 1/2 mile in open territory, all of mine almost made that spec, but if it is too loud, weld a washer to the open end of the pipe, make no difference to the performance of the bike a but a big difference to the close proximity sound level.
I bought 2 from the first Morebank auction and ran them for around 12 years, as daily transport including two All British Rallys at Myrtleford, ridden from Sydney 2 up and 2 more solo. I geared mine up drastically and ran it as a 3 speed with top as overdrive for highway use only. Loved every minute of it.
Wow thanks for the Info Trevor, that's exactly what I was after. Getting a copy of Rupet Ratio was the first thing I did, there is so much useful stuff in there. I'm pretty excited about working on this bike and can not wait to get her on the road.
Do you know if the fuel tank was the same as on any other model? I'm finding it difficult to find one that looks right.
Yes they are identical to another model. However if I tell you on an open forum then they will go from difficult to find to impossible to find at 5 times the price. Split the crank and replace the big end before you get too far into the project. The journal is parallel pinned so you will need a big press to do it yourself however any real Harley or Ducatti workshop wil be able to do it for you. You will need to measure it very carefully as there are several variations in widths. If I had a functioning brain when I did mine , I would have written it down when I had mine done. The 6.5:1 pistons fitted were unique to the GA series and are hard to find but standard B40 ones will be fine. I think the flywheels are heavier than standard items as well. Quite obviously the team that drew up the specs for them were looking at the M20 spec sheet at the time.
Check the filling neck height on the three oil tanks you have there, if you are lucky enough to have a short one there then fit it as the long neck will chew into your thighs when you kick start astride the bike and leave you with blisters if you ride any distance bum on the seat.
Check this carefully as the oil tank is the first thing that goes into the frame so if you want to change it you have to pull every thing else off to get it out. The light khaki is original & was brushed so if you are thinking of military trim that will make it easy to finish. The dark green is full vitrious enamel factory finish and is next to impossible to get off. Neither chemicals nor heat will touch it so I suggest you do the same unless you want to put in hundreds of hours with wet & dry. I foolishly tried to sand blast my rims and it took 7 hours for each one in a garnet cabinet . Being a field machine all parts normally chromed were painted with silver frost as was the crank cases , head & exhaust so again if you go for military trim you are going to save yourself a lot of work as the sliver frost looked like it was done with a 8" broom. Spokes were also green.
Check the foot peg mounts carefully they are braised on and the bronze tends to crack, I had to do both of mine and on one rebraize the cross brace with the center stand on that was rotated backwards which seems to be common problem.
Unless you are built like the proverbial brick out house get the seat redone with thicker foam. The seat is another Aust army spec using a secret bullet, bomb & mine proof foam that is harder than concrete and 50 years will not have made it any softer. We used to fold our anoraks and sit on them when we were going on a long ride. Others used two sheep skins and another member fitted a water seat ( remember them ? ) Don't see any wheels there or the air box or the tool box.
Is there an easy way to remove the sludge trap screw from the flywheel after it has been locked in by What I'm assuming is a centre punch?
Remove the centre punch on the plug by using a small drill, try not to remove any material from the flywheel but its not as critical as on a twin. I then drill the centre of the plug with an 8mm drill before then driving an 8mm allen key into the resulting hole. The key can then be turned taking the plug with it, you can try a 7.5mm hole first.
Chock the crank and use a big hammer with an impact driver. If it does not shift with 1/2 dozen efty wacks then you willneed to get a dremel and a fine point burr to cut out the punch. They ae not usually done up all that tight which is why they are peened with the center punch. replace it with a modern alloy allen headed grub screw. The alloy will expand more than the crank and help hold it in there tight and they are much easier to take out with an impact gun & inhex socket.
Trevor... lots of interesting history re: the Australian WD's, and WD's in general as well. Thanks for sharing.
Chris - I have a '67 ex UK Army WD that was demob'd and civilianized following a short life with a British army reserve unit. It found it's way to the US courtesy of a friend who used it while in university in the UK as his daily transport in the early 80's.
Mine was not in a box when I got it, but not long after I bought it from my friend in the early 2000's that it made it became apparent that work was needed. All but the bottom end were dug into.
Between Rupert, local BSA knowledge and help from friends here, as well as loads of help from Lee Mitchell at http://www.bsawdb40.com/ with parts & advice - I was able to return it to close to original.
It is a great fun and reliable bike. Being my first ever motorcycle it does hold a special place in my heart & head.
Will look forward to checking in on your progress - and learning even more.
So after being busy with life, I'm back at the bike again.
Can someone confirm if the drive side layshaft needle-roller bearing goes in with the part number markings visible? or does it not matter which way. I noticed that one side is flat and the other is slightly rounded.
If you are in the box, fit two stiffener plates to the detent spring, the single one is not up to the job. The detent was another problem, they commonly break then you are stuck with whatever gear you are in + one either higher or lower, not much fun if you end up with first & second 300 miles from home. On both of mine the detent bolt holes were buggered and needed to be helicoiled
It should read B40GA_xxx where XXX is a number between 001 and 476. They were not stamped particularly deep and it should match the engine number as by the time thy were using B40's the old engine swapping days had long gone.
If the numbers are outside that or there is another digit in there then the bike was stolen. Five members ( incuding myself ) had their B40's stolen and I seem to remember a few CEMCC members lost theirs as well.