nigelog

Hi mcman, I had a look at that bearing spec. If they manufactured one that fitted a 1" shaft I'd machine half the case away to get one in. Looks what is needed but I didn't have the time to investigate all the size possibilties. I'm still waiting on my bearing experiment to see how it looks, can't hurry along the engineer when they are family. As a distraction I'm investigating fitting a changeable filter such as a Triumph T3 filter inside the oil tank. It will give me the excuse to remove it and get rid of those weld marks. ta nigel

Hi Sparks, thanks for input. It appears that not only pattern parts fall into this wandering tolerance area. I think that taking into account it is the springs location in the camplate that should dictate the position I am going to wait until I have all the bits together then either try to raise the spring slightly or remove some material from the bottom of the camplate. 0.5mm over a length of only 5mm should suffice. I'm beginning to believe the adage "never fly to England to buy a bike the day after St Patricks Day".

Hi B40RT - they are essentially the same and if your B40 doesn't clunk I don't think mine should, I only ever used 4th gear once in the time I had the bike running so I cannot say if this is new or not. I was thinking of reversing the gears but I think I'll wait until I get the reamed bushes back and when assembled see how far I can lift the camplate spring, to move everything upwards, while still engaging all the gears. If that fails I might leave it as I am hardly going to hear it with the engine running and it wasn't jumping out of any gears. Maybe a Monday morning assembled bike. Hi Craig - have the book and find it invaluable. No mention of this particular ailment but then it does say it cannot cover everything in the disclaimer. '79 was the last time I rebuilt an engine and cannot even remember if it was the Yamaha or the Greaves.(Hope I didn't get the parts mixed up) Rgds Nigel

Hi while assembling the gearbox components I fitted a new camplate spring, second hand camplate (identical) because point at 3rd gear postion on trackway was not worn on the spare I found in a box. Spring was set at correct height, when depressed, in relation to cam pivot and all seemed well. Assembled the cases to check and found that the camplate makes a definate clunk against the bottom of the housing when selecting 4th. Viewing with a bright light spring is engaged in camplate correctly. Looked at the old camplate and there was no wear mark at the spring/camplate location to indicate that the cam was being held out of place by the lowest point of the camplate meeting the casing. Re-assembled the old components, including spring, and found 4th still clunked against the bottom on the casing just inside the oilwell. I cannot assemble all of the components to see where the gears sit at this point because 2 bushes are away for reaming to size. Is this a "normal" method BSA used to secure the camplate firmly in position in 4th gear or should I remove metal from either the camplate or the casing. As the pinion is traveling towards the sleeve gear to engage it would seem to me that this firm hold between camplate spring and case actually would hold the pinion slightly away from the sleeve gear instead of possibly pushing against it. Any suggestions or past experiences appreciated or I will have to wait for the rest of the components to see if this will be a problem or not. Many thanks Nigel

More likely to restrict oil flow. If you go the route of a housed bearing you'll have to work out a way for oil to reach not only the bearing but also the big end which is fed through holes in the crank. Your main feed will be coming from the pump up through the non-return valve and out through the oilway at 6 o clock when you look from the inside of the crankcase. If a bearing outer is against that there will be nowhere for the oil to travel any further. I dont know about machining an oilway in the outer but if you remove the original bush outer from the crankcase you will find that it has an oilway all around its outer surface to feed the other oilways around the circumference and also to dump out through the pressure relief valve if needed. I dont think therefore there is a way to do it without either the sleeve and bush outer or convert the crank to end fed. If I think of anything I'll let you know. Ta

I searched for weeks and could not find a Vandervell replacement bush so I gave up. There are complete units available but 2 things put me off. 1 pattern part quality varies dramatically, some bushes I have bought are fine, some need reaming which adds to the cost. Seeing that all shafts seem to be 2thou under a stock bar size I would have thought it easy enough to provide a useable tolerance without reaming, I know this can be handy at times if your shaft has worn undersize, but I have just found it awkward. 2 the replacement bush whether bush only or bush and outer would have to line reamed once in situ through the 2 assembled cases. Probably very easy back in the 60's when everyone was geared up for this but I did not even bother investigating that one. The outer and sleeve are hardened but it is possible to machine and hone rather than cylindrical grinding. If mine gives up in the first year I'll know if that is true or not but I have asked the advice of a bespoke manufacturer here in Ireland and they agree. If it all go's wrong All I have lost is $50 and a bit of time and I can go back and buy the C&D product which does not require line reaming Ta nigel

Hi mcman, both the bronze bush outer casing and the crankshaft sleeve are re-used. Machined to the 38mm and 32mm respectively it only needs the sleeve to be shortened to suit the two thrust washers. I have used 2 x 1mm circular saw blades (machined to size) that were lying around for the washers as they appeared to be a nice tensile steel. The sleeve would have to be machined shorter from both ends to keep the internal oilway track central over the feed hole in the crank. The oil feed to the bearing will still come through the holes and the external oilway track in the outer bush housing. I have while waiting for the bearing to come back from the machine shop spent a bit of time overhauling the non return valve and the pressure relief valve as I dont want to have to strip this again. I'll post a pic of the finished item when I get it. The parts that went for machining can be seen on the blog site mentioned earlier on the thread. C&D will send a two part flyer with photographs and an explanation if you ring them. They are very helpful and their kit is supplied with new outer and sleeve components, needle roller and washers all ready to go. I had time on my hands and an uncle with a machine shop so I took the family favour route. (I gave him an engine for his go-kart so he's all right about the work) I would be very interested though if anyone knows the dimensions of the C&D supplied needle roller, its not specified on the flyer. Ta Nigel

C and D autos in Birmingham do an off the shelf needle roller for St

Hi all, for anyone interested in rebuilding the C15 engine I have started a BLOG that will go step by step through the process. I am not an expert, and this is the first engine I have rebuilt since 1979, but I had a sound engineering background before changing tack to IT. Anyone is welcome to look and comment if needed as I am definately not the first to do this and their are problems which have already been solved by better minds. Target date for completion is February 2009 - as I am still gathering the few elusive parts. http://rebuildbsac15.blogspot.com/ Vinnie, I scrambled in my youth and had the run of a farm on a 125 Bantam, but never tried trials although I followed it with interest. I would consider competition if there is a class for 46yr old complete novices. I had given up onthe idea of trials riding in Ireland (although 70% of the countryside would qualify as a course, including the roads). I found in my box of engine bits an 18 tooth primary drive gear with short primary chain to match and a 17 tooth gearbox sprocket. I was going to sell them but I think I'll hold on to them, I will gear for road with the 23 primary and 19 rear and keep the others as a "trials kit" in case anyone calls to Ireland. Would my Ohlin reservoir shocks qualify as I like the extra height and bit of bounce??

This is the set up on my engine. No pin evident and I have shown the internal parts of the complete shaft assembled. Lower shaft held by grub screw that bites into bush at top of lower shaft. Distributor held by the clamp

Hi A few weeks back I asked the forum for help collecting a bearing I needed from New Jersey and posting it to Ireland. I now have the bearing and can get on with the rebuild with thanks to the kind assistance from Paul. Paul bought the bearing from a distributor and then posted it on to me as they are unavailable in Europe. Bearing was to convert a BSA C15 to needle roller rather than plain bush on the timing side. Thanks Paul and thanks also to Darrell Shannon who was helpful but left for Ireland before I could get the bearing to him. The Trials Central Forum came up trumps for me. Rgds Nigel O'Gorman Ireland

Hi, I have taken a few photos of the distributor set up on my bike and will post them up for you. I decided to record this rebuild to fill the time as I am assembling parts. Can be seen at http://rebuildbsac15.blogspot.com/ Will post the pics up there later today. Ta Nigel

Agreed. But in the early days of the internet information was a lot easier to get hold of. There are more and more restrictions to the free availability of information. You have to pay to join many sites before you can even ask a question. Nobody wants to spend resources on creating a fabulous website with no return, but it has to be tempered with the longer term picture.

One new old stock shaft with bush inside and kickstart gear with bush just went for

Hi, can sympathise with you looks like your bike was run on honey as a lubricant, mine was more like carborunum treacle. There is a pin holding the shaft but care should be taken. Concentrate on freeing the clamp bracket which is situated at the top in the alcove first. Halfway down the tube holding the shaft there is a small 2BA grub screw which holds the bush in place which in turn holds the shaft from being driven up from below. If the head is bollixed drill it out as you have plenty of surrounding "meat" to re-drill and tap a larger replacement. When this is removed, with a soft metal bar tap the shaft up from the bottom, it can be accessed with sump plate and oil pump removed. Dont try twisting from the top as the metal used in the distributor housing has been oft described as "cheese" and will distort instantly. If after all this it is still stuck it is possible the worm gear cannot turn to allow the shaft to rise upwards. Youll have to remove the worm gear. When is finally comes apart and you can see how it was assembled first day you will wonder what all the stress was about. Feel free to contact me with regard to rebuild as I am half way through a rebuild with one off replacement timing side needle bearing option and full bearing and bush rebuild. I could save you a lot of time and money and research as I have just been through it. 6 months now and only now starting the assembly stage. Rgds Nigel Looking again at your top pic I have not seen what looks like that pin before. I take it it cannot be seen from inside the casing. If other instruction above does not loosen distributor it looks as if you may have to drill and use a stud remover to pull it out. I cant see why they would lock the timing so restrictively as you need minor adjustment even with electronic timing. That bottom of the pins in top pic might just be holding another bush in place fitted after factory. Best of luck with your efforts, but resist the temptation to belt the **** out of it as good replacement parts are expensive.

Hi DG Shannon/Paul Thistle the bearing is a needle roller I will use to make a conversion to replace the timing side bush on a BSA C15. The reason I need one from Consolidated Bearings is because they are the only manufacturer who produce a K - 32 x 38 x 23 needle roller. There is no European equivalent. The nearest in Europe is only 20mm wide losing me 3mm of bearing surface. As I only intend to rebuild this engine once in my lifetime it makes sense to be resourceful. If you are travelling from Dublin to Blarney and on to the Ring of Kerry you will pass within 500 yards of my house where the bike is in a shed. If you get as far as Macroom with the bearing in your pocket I'll cover any costs and buy you a few Guiness. I can prepay Consolidated with a dollar draft for the $10.95 and get them to post it to a local address in US. If you are travelling that route in September I can recommend best routes from A to B and also best watering holes I've encoutered after 20 years on the road. The one thing I will warn you to expect though is the cost of eating out in Ireland (expect to pay double for half as much as you are used to). Let me know what you think. Rgds Nigel If you want a spin a the bike though you'll have to do it on the way back from Kerry while I get busy with the spanners

Hi any helpful person in Cedar Knolls area of New Jersey able to do a favour for me. I have located a bearing I need for a vintage BSA trials bike in New Jersey. It is unavailable in the size I need anywhere in Europe. The makers are kind enough to sell me a single unit at $10.95 but because of their internal systems for overseas orders they would have to charge $25 for wire transfer cost and a further $75 for UPS. Brings the price up ten fold. If I send them a dollar bank draft and a local address they can send it out (rather than sending me through a distributor at a bigger cost). So if anyone out there is willing to collect this bearing from Consilidated Bearings and stick it in normal surface post to Ireland I will buy them a few pints for their trouble. Much appreciated if anyone can assist Rgds Bearingless in Ireland

Hi thanks for the replies. There was no spacer under the barrel as it appears (from memory) that comparison with the C15 piston showed it to have a lower crown, lowering compression. Piston, bore and rings are very low mileage by their looks and will be kept. I will check the swept capacity at rebuild. Damage went further than a pushrod ( which looks as if bent by man when head last fitted). There is another problem listed in another thread with regard to the lower oilway from oil pump to timing bush bearing. I am intending cutting a channel in the ali casing to align feed to some degree. Then its rebuild time. (see other thread for details). Thanks again, rgds Nigel

Hi Chewy, as you state the pressure release valve should be on feed/supply side but is not quite. BSA engineering no doubt. Following the feed route the oil leaves pump and heads through the crankcase to a non-return valve. This one of the two oilways for timingbush. Looking from the inside of the case there are 2 oilways in the bearing recess 1. drilled at 6 O'Clock is the non return valve 2. drilled at 9 O'Clock is the pressure release valve oilway. Once through the non-return valve the oil passes through an oilway in the steel bearing outer seat to the bearing bush itself. It has two paths from here, first is through an oilway in the inner bearing bush to the crank to feed the big end, second in the case of over pressure is though the oilway at 9 O'Clock to be dumped into sump. Now I've had a better look at it, leaving aside the phosphur/bronze bush which could have turned, if the bush outer is fitted with the machined faces located in their keepers (which it has to to seat) the oilway at 6 O'Clock (feed) is restricted by 80%. The oilway at 9 O'Clock is OK (dump to sump). The pressurised oil feed through the bush/crankpin to the big end must have been abyssmal and luckily the big end is the only bearing that does not need replacement. I will need to enlarge the mouth of the case at 6 O'Clock for the oilways in the outer seat to function. As you state dremel/burr is the way to go. On further inspection the inner bush seat also has oilways one of which should line up with the oilway in the crankpin. Again the line up in this case is retricted by 80%. This seat also has to be replaced so I will align on re-assembly. How this was not noticed on last assembly is a moot point and may even have been BSA as I can see no evidence of futher rebuild. It is 30 years since I looked inside any bike and even in those days I would have just re-assembled and ridden on until the next bang. Either life was easier then or money is harder to come by now to be wasting. Cost of this bearing job for the mains Timing bush inner

Hi, on stripping C15D engine with timing side bush, bush was seriously shot. Phosphur/bronze bush had either spun or been fitted incorrectly as the oil feed visible (pointing to anti sump valve) had closed to a eclipse equally about 10% of throughway. After removing bronze bush to replace I noticed that even though the steel case insert has machined faces to locate it vertically when fitted in case, the oil feed holes here do not align correctly. There is a devience of a few degrees. To open the oilway fully I would have to enlarge one side of the oil feed holes (in the case I would have thought preferable). Which of the two is less likely to cause a problem, opening the feed to the anti sump valve, or opening the feed to the pressure release valve. I would appreciate any help as it cannot be left as is, as another rebuild with the same inherent problem will just result in another bush failure. Many thanks. Nigel

Turns out it is a B25 piston (same bore different gudgeon pin height). Any ideas how the different pin would affect compression/clearances, or how they might have got around the difference. Any input appreciated. Rgds Nigel

I removed top end to find source of rattle (bent push rod) and while checking conrod this piston was revealed. I am wondering is this a stock item or has it been machined specifically (for what purpose). The numbers are AE 16945 413 IL82 GI and top is marked STD 5LL. I have tried looking up web for catalogues to no avail as I would like to replace rings. Any Ideas as to where I can source these.

Found this while looking for a set of forks. Might be awkward downhill though http://www.youtube.com/watch?v=giSQ-c_v-xI ta

Hi All, have a small oil leak from top of push rod tube so decided so that bike can stay running I would refurbish a spare head that came with it, so I could upgrade when I get round to repairing the leak. On inspection of the spare head and the removal of the valves (guides came with them) it turns out both valve guides were loose in the head, exhaust guide snapped in half at the line of a spring clip and the inlet valve spring broken. Looking down the inlet port it has been reworked with all of the aluminium boss for the guide removed and the guide was tapered to increase flow. This is a suggestion I have read in Rupert Ratios book but he did have a warning caveat regarding the complete removal of the boss completely due to less support for the guide. Is this recoverable with the fitting of new oversize guides or a junker and I should have a look at the head on the bike. Also any suggestions as to where I could source matching valves/oversizeguides/springs or better still someone who could refurbish the head and return ready to fit. I would be worried that it may repeat its valve guide disintergration possibly causing more damage than it is worth. Any experiences/advice greatly appreciated. Rgds

Hi Dave exactly what I am looking for, tidy mounting bolts and all, at that price beats clambering around the scrap yard. Many thanks