Finally got the Cyclone to fire up for the first time after the engine rebuild. Wow what a sound the open pipes make, but smoking badly. After a few minutes it has black oil dripping from the left exhaust port. Now thinking what went wrong. New pistons and rings on standard bore cylinder, new valves and guides. What do you BSA unit twins people think. The shop (Rabers in San Jose) assembled the lower end. If the timed breather wasn't assembled correctly would that cause oil to push passed the rings? Wanted to get some feedback before pulling the engine apart. Still pretty excited about the fact that it runs.

Thanks,

The possibilities are numerous.

However, you could have "wet sumped" the engine over time, especially if the oil pump gears are worn. Did Raber's cover the oil pump, or did you install it after the fact?

Just drop the crankcase drain plug, empty out the sump, re-check the oil tank level, and go for a LONG ride (like an hour, at highway speed when possible).

Upon your return to your driveway, see if it's still smoking or leaking abnormally. While it's still hot, nip up all the barrel bolts, crankcase bolts, and engine cover screws. You do need to do at least one good head re-torque, IN PROPER SEQUENCE, before too long, like about a tank of gas.

Thanks Grandpa,

Well worth checking wet sumping before doing anything like tearing the engine down. This bike isn't going for any rides for a while. Mainly wanted to fire up the engine to make sure it was assembled properly by Rabers before any recourse expired. Raber's did not assembly the oil pump. Need to find the oil sump drain plug. Needless to say this is my first BSA twin - many, many Nortons of single and twin persuation. Similar, but not quite the same.
It's a bit farther along than in this photo:

DANG!!!

I need to get my A65 put together and find a set of those scrambler pipes. That's exaclty the look I'm aiming for.

Just fish around the bottom side of the engine, it will be obvious where the drain facilities are.

Hey Grandpaul,

Fired up the Cyclone last night and not much oil smoke. Hopeful wet sumping was all that's wrong. Still not certain I got the rings in right side up. Nice sound with open pipes.

illf8ed wrote:Hey Grandpaul,

Fired up the Cyclone last night and not much oil smoke. Hopeful wet sumping was all that's wrong. Still not certain I got the rings in right side up. Nice sound with open pipes.

The neighbors can't like those open pipes.

I don't think those pipes could be all that loud. My neighbors haven't complained about the pipes on my BSA.

Hey Rob,

You live within 70 miles of me. Give me some warning before firing up those open pipes.

Aaaah, I think mine is quieter... How can I be the judge, I ride a Harley.
I don't have the required "Thunder" header but the Vance & Hines pro-pipe loves car alarms

Opened up the engine today to see if I can identify rings installed correctly. Also have a wall chart for assembling A65/A50 of the 1964-65 persuation. Still can't see any marks to indicate which way is up, but had another ring set with one per piston having a "T". The wall chart says only the middle ring (only) is tapered and has the T. Now I'm certain the rings are correct. Noted the head gasket looks like the oil leak culprit and the pistons had oil puddles in the cut out area for the valves. I'll give Raber's a try for new cylinder base and head gaskets. At least I got the timing to where the engine fires.

Dave do you have a repair manual? I could help you with one.

Rob94010 wrote:Dave do you have a repair manual? I could help you with one.

I have a Haynes repair manual and several of Roy Bacon's books such as BSA Twins Restoration.

Thanks,