Priming oil system after rebuild

[Peter A]

I have just completed an engine rebuild on a 1971 A65 FS. It's had a main bearing conversion, crank re-grind and cylinder rebore. Before firing it up I want to prime the oil system using the kick starter. Should this provide enough input to the oil pump so that I can observe oil coming out of the rocker feed pipe and oil return from the sump to the oil tank (in-frame)? Any advice appreciated, thanks.

[rhyatt]

On my rebuild , I used clear oil pipe on the feed side , filled it with oil so as the oil could dribble into the pump gears , then turned the engine over whilst blowing into this clear pipe ,
Initially it wouldn't pump by the pump , so I removed the PRV and this let it get into the pump whilst blowing/kicking.
I then kept the clear pipe to facilitate circulation checks

[Peter A]

Thanks for that Rhyatt, certainly worth a try.

[DAVE BRADY]

Hi,

There are a few threads on this so do a search.
I found that turning the engine by kickstart/hand that oil could be pumped back up to the tank and rockers but first some oil must be put in the sump via the drain hole by the cam followers. About 1/4 to 1/2 pint is usually enough.  A bit more difficult is ensuring that oil getting through to the big ends before initial start up.  Obviously plenty of oil is applied during assembly but it is easy to get a bit of an air lock/bubble in the oil feed from the tank.  As the pump is designed to pump oil it can struggle to suck the air through and it quite possible that oil is not being pumped to the big ends.
Do as suggested by Rhyatt or still use a rubber type feed pipe and a pump type oil can to help get it through but ensure that it is full of oil when connected to the tank.  Once you know that the oil is getting pumped through refit the PRV and the oil light.  Keep turning the engine as before until the oil light goes out. This indicates that the crank is full of oil and that oil is meeting the resistance of the big ends.  The light will go off after a few seconds when you stop turning the engine.  This helps to indicate that oil is getting through the big ends and that there is flow as well as pressure at low revs.

Dave.

[Peter A]

Cheers Dave, more good advice.

[V500]

Just do what they did at BSA-
lube the various rotating etc parts on assembly, fill oil tank, a slop of oil in the tappet covers, tickle and start. All that kick-kick-kick routine or even the daft "take it for a walk" thing isn't necessary.

[limeyrob]

If its all slathered in oil on assembly it should be OK but I play safe and take plugs out, put it in 3rd or 4th and push it until I see oil.  I now have a paddock starter so I use that.  I do it because it means I can be sure the sludge trap is full, the pump is working and the pipes are all connected and flowing.  Also my RR now has a return filter and it takes a while to fill so the engine would be running a while and if I'd made a mistake I wouldn't see it.

[Gup holland]

I had the same problem after a rebuild, didn't get any oil to the oprv. Disconected the oil feed from the tank and pressed oil in with the oilcan through the feed to the pump. Had a massieve airbubble there. When oil came out of the Oprv I put the feed on and kicked the engine, after a few kicks there came a Sissing sound of the bearings of the crank and knew that the sludgepipe was full.

Had I start the engine maybe it have could go wrong, go for safe!

[DAVE BRADY]

Hi,

BSA had to get bikes off the production line in a certain time. We do not have that time constraint so I would say anything that gives our engines the best start in life is worth doing.

Dave.

[scifi]

Well BSA would not have had old blocked oil filters or full sludge traps.   Also new oil pumps could pump air as well.

[DAVE BRADY]

Hi,

Hopefully a rebuilt engine will not have blocked filters and sludge traps but it has been known.

Dave.

[limeyrob]

Or pipes round the wrong way, it happens.