After what seemed forever i have got my 66 Spitfire back from having a full engine/gearbox rebuild, this was carried out by SRM Engineering,anyway its back.... so its 1st start up Today and a short ride out seeing its a nice day. A little alarmed that on the start up i noticed it smoking from one of the silencers :-( thinking its maybe a bit of oil in the pipes etc i gave it a short 6 mile run out thinking it may clear, no such luck, should i be alarmed or maybe its just bedding in? Any advice appreciated before i give them a bell Tomorrow.. Thanks Steve
Sounds like the rings are not bedded in correctly and to do this you need to run the bike up a steep hill a few times in second gear with plenty of throttle. Do this within the first few miles of initial startup.
BSA's use cast iron rings which need bedding in against the previously honed cylinder walls. Theres only a small window of opportunity to achieve this before the honing wears down. Ride the bike hard for the first few miles as suggested and the rings should bed in and seal.
1968 A65 Firebird 1967 B44 Shooting Star 1972 Norton Commando
Ive never had a new bike puffing smoke out when everything has been done.
Ride the bike normally up to operating temperature then allow to cool, repeat over several cycles.
SRM sell gpm pistons which I am inclined to assume will be fitted to your bike. Great Pistons but shite rings. They do seal poorly and by the time the bike had done 1000 miles it was blowing more fuel past the rings into the oil than was being burnt. That said, 7.5:1 Pistons and with this trouble and it still did 95 mph! But if thrashing it was giving me about 10mpg.
I would contact SRM before you do anything. They may have some excuse for it. They may say, just run it. But with ever. Only do it with their say so and written word that if you do that and it worsens. They will sort the fault.
If it were me, I'd pull the top and and fit Hastings or total seal rings in their. But if it were me those would already be in their because I built it.
If it doesn't improve the bores will be glazed by 1000 miles. Deep straw colour! Fresh rings and a hone will sort the problem and you won't be taking any more off than 0.5 thou by doing this
First try gunner advice, if you don't have a hill in vicinity, use a normal road with a few hard accelerations and deceleration after. Do not keep steady high revs and before starting to accelerate get an engine to normal working temperature by easy cruising for 10 - 15 min. I have GPM pistons with original rings in my engine, but after above treatment I didn't have any problems with them sealing. Remember to use only cheap 20W50 mineral oil, and change it after 100 km. Next change after approximately 500 km and after 1500 km change to the oil you 'd like to use in this engine.
Ive just rebuilt my a65 , on initial start up there was no smoke , boy was I chuffed with myself ! but , after leaving it for 3 weeks while away , I came back to start it and it smoked on the left hand side for about 20 mile.......its just wet sumping , normal stuff , some are worse than others. you don't know how much oil was left in the sump by srm , they may have been over cautious and put a bit to much in , I,m not so sure about the thrashing up the hill bit , old engines in my opinion need to be run in properly. There were no hills near small heath ! Just ride it for 20 miles or so , don't labour , a bsa engine needs at least 3000 rpm for good pump pressure , this should remove the oil from the sump and go some way to running in your engine. If it smokes after you've done 100 miles when warm......then you can contact SRM
1969 BSA A65 Lightning 1994 moto guzzi California Triumph sprint GT 1971 BSA B50 Victor special 1968 BSA B44 SS