Recently my 1971 underwent rebuilding. After reassembling and first start up it ran well having new rings and pistons installed, but was smoking a little at first but then worsening. We then Removed the spark plugs to find the the plugs and piston heads covered in gasoline. Now after the engine runs for a while oil begins to start poring out of the side just inside the drive sprocket housing spilling out just under the chain, which blocks your view to see where exactly it is coming from. If the motor sits over night, the start is difficult and once the motor is running it puts out white smoke but doesn't leak oil. after it runs for 5 to 10 minutes the oil begins to pore out once again. Any ideas what is going on here?

the oil is coming out of the crank vent which is just in front of the countershaft sprocket,my 68 A65 did the same thing due to it needing a fresh build so I removed the primary assembly and countershaft sprocket and using a light and mirror cleaned the area sealed with JB weld and vented the engine thru the rocker cover per some ideas I got from the britbike.com forum,a rebuild in it's future
your engine may be getting the blow by due to the fresh engine needed to break in,a leak down test will show if there are any problems like incorrect indexing of the ring gaps
the over rich condition sounds like normal amal problems like leaking needle/seat assy
hope this helps

I just stopped by mikes shop where your bike is at which is just down the street from the shop I work for,and let him know what to do to "fix" this,blow by is most likley from the fresh engine not being broken in

Thanks for the info... I was down there today to start prepping for paint. Mike said you just left about 5 minutes before I got there. The fix sounds simple enough. Just wondering how this was never an issue on new bikes that came fresh out of the factory back in the glory days? (not that I doubt your solution, just seems counter intuitive to drill a hole into something you want to STOP oil leaking out of! Ha!) I was hoping to have the bike broken in to ride down to the spring rally this year, but I don't think I would have time to break it in before then. We'll have to pick your brain on some of the finer nuances of clutch adjustments on my 1975 R75/6 the next time you come down. Thanks Again... Matt.

sure,no problem,mike had said this was a bit of a "green" rebuild being kind of new to this stuff so I may hazard to guess if the problem does not clear up the the top end may need to come off and ring orientation checked as the gaps in the 2 compression rings and the oil control ring need the be 120 degrees off each other,I have seen a engine where the owner lined them all up(?) which cause one hell of a cylinder leak,a leak down test and compression test will give you an idea of what the engine condition is before any tear down
one thing I did not ask was does it stop blowing oil after start up?your engine may just be wet sumping and this can be due to the check ball in the pump sticking

I don't think the rings are lined up as we were careful to ensure they where staggered. wet sumping seems more plausible, but it does not clear up after start up, just the opposite actually. It takes at least 5 to 10 minutes for it to start spilling oil which of course is accompanied with the smoking out of the exhaust. Before every engine start the sump is drained and about a quart of oil comes out, then when we restart the engine, which is consistently after one or a few more kicks, the engine runs great until the oil builds up in the case and the smoke returns... always the same 5 to 10 minute time span. I think the venting procedure you came up with will do the trick, but I'll keep you posted.
MATT.