After many years of restoring my A10 café racer. I am now at the point of starting the bike, which is proving to be tricky. I think my problem is with the ignition timing. When building the engine. I think I must have set the timing ATDC rather than BTDC. So it would not start. So reading on this forum the opinion seems to be to set the timing 5/16" BTDC. So pencil down spark plug hole. Bring it up to TDC and mark the pencil. Measure 5/16 up pencil. Using the rear wheel to turn the motor over rotating wheel as though bike moving forwards(keeps going past the mark on the pencil using the kick start). As the piston is coming up to the mark on the pencil. stop, take of magneto drive (with auto advance), Rotate mag till points are just opening. Lock auto advance to full advance. Bolt mag drive back on to taper, check points are in same position. Still doesn't start. Ok change HT leads over. . Tickle carb, open choke, now it kicks back and backfires through the carb So question is what am I doing wrong. with it backfiring through carb is ignition too advanced or too retarded? How critical is the ignition timing to at least get it started? Is there an easier way of setting the ignition timing on the A10. Am I missing something. How much oil should be sitting in the sump. If I open the drain plug I am getting about 1/2 a cupful is this normal?? My Panthers don't give me this much trouble. I have tried setting the timing about 4 times now. Any thoughts much appreciated
After you have got TDC then you need to rotate the rear wheel BACKWARDS as the timing is BTDC (=BEFORE TDC)by the 5/16" as measured on your pencil. It should then start. If it doesnt then swop the plug leads. Not sure of your engine spec--BSA quoted several different ignition firing points over the years for engines in different states of tune. Actually purely from memory--5/16" BTDC is more typical of a 500 A7---for an A10 650 something like 3/8" BTDC is more typical. HTH
I don't know what model A10 you have but according to the BSA service sheets the A10 Gold Flash ignition setting 11/32" BTDC the Road Rocket and Super Rocket 3/8" BTDC. Trying to get the piston in the correct position using the kickstart is not ideal, put the bike on the stand with the rear wheel clear of the ground you may have to put a bit of wood under the stand to clear the back wheel. Put the bike in top gear then with both plugs out working from the primary side put your left thumb over the plug hole and turn the back wheel forwards until you feel pressure on your thumb then that cylinder is on the compression stroke. Remove your thumb then put your pencil down the plug hole turn the back wheel forwards until you get TDC then mark your pencil, then remove and measure the correct setting on the pencil. Insert back down the plug hole and then turn the wheel backwards until you go just past your mark then bring the wheel carefully forward until you get to your mark, doing it this way takes up any slack in your timing gears. Then using a small wedge jam the auto advance mechanism open this is full advance. Set the points until just breaking open I use a cigarette paper for this then refit the auto advance unit remove the wedge and now the bike should start. I should also say that sticking a pencil down the plug hole is not the most accurate way but it should be near enough to get the bike going.
Hi Guys, Thanks for the replies. I was told its a 58 Golden Flash, but checking numbers on the BSAOC it appears to be a late 61 Golden Flash. According to my Haynes manual it should be 11/32 BTDC, but reading elsewhere on this forum it says 5/16" is better. So I have just got hold of a timing disk. Anybody tell me how many degrees 11/32" is. I mite try it at that unless anyone can advise otherwise Thanks Bruce
Sorry but I don't know how to convert the 11/32" to degrees but someone on this site will, I believe it has been asked before. In regards to the different settings advised what you have to remember is that the 11/32" was set by BSA when your bike left the factory but a lot has changed since then in regard to fuel it is not anything like way back then, even different in different countries. So all I can say is in my own case when I had my 1957 Gold Flash here in the UK I set it at 11/32" and had no problems I had the bike from 1996 till 2012 so it was used with leaded and unleaded fuels with no apparent problems I did however use an additive Castrol Valvoline for the effects of unleaded but if it did any good or not I do not know I still use it on my A65 but mainly for peace of mind as I have read a number of articles on the subject of unleaded fuels and am not convinced either way about valve seat recession caused by unleaded fuel.