The BSA A7-A10 Forum

Technical => A7 & A10 Engine => Topic started by: Hubie on 02.08. 2012 07:28

Title: Failure! Oil pump I think...
Post by: Hubie on 02.08. 2012 07:28
G'day chaps,

Been a while since I posted, probably because everything has been going so well since the rebuild of my flash.  Today however was a different story and I need help with a diagnosis;

About half way home I noticed smoke coming from the back of the bike.  I kept an eye on it and it got progressively worse until I stopped on my drive (the trip is only about four and a half miles) and there was oil everywhere!

I drained the sump (srm after market job) and much more than there should be poured out.  I topped the oil tank up, checked and cleaned the oil pressure relief valve.  Started her up again and after a while the pipes (especially the right one) began to smoke again and there was oil positively pissing out of the breather. 

My guess is the oil pump has failed, at least on the scavenge side has failed and I really hope I haven't done anything terrible to the bottom end.  It doesn't feel any different at least  *sad2*

Any help would be great.
Title: Re: Failure! Oil pump I think...
Post by: Brian on 02.08. 2012 07:38
I would start with the pick up in the sump Hubie, make sure it is not obstructed and the ball moves freely. It would be most unusual for just the return side of the pump to fail.

Do you have an inline filter fitted ? If you do check that, basically anything that can stop the oil returning to the tank. I am assuming when the motor is running there is no return to the tank ?
Title: Re: Failure! Oil pump I think...
Post by: Hubie on 02.08. 2012 07:45
Thanks Brian,

I will have to take the sump drain back off again.  I bought one of those new SRM ones and fitted it a few weeks ago.  That is the only thing that has changed.  I'll check that though and see what happens.  There was a small stuttering amount of oil returning to the tank until the sump filled up.

Cheers,
Dave.
Title: Re: Failure! Oil pump I think...
Post by: duTch on 02.08. 2012 09:22
Hubie,
        maybe the oil pump base has come a bit loose,or not sealed well and sucking air, I would think there shouldn't be that amount of oil in the bottom?
 If that be the case, then the feed also isn't doing it's job. Also check your Oil tank breather as discussed a while back, at least as a matter of course!
good luck.
 Cheers duTch
Title: Re: Failure! Oil pump I think...
Post by: Topdad on 02.08. 2012 11:01
Good morning Hubie, had the same problem 'bout 4 mths ago ,have you by any chance got any anti wet sumping valves fitted in the lines ? mine had jammed not a drop getting past it ! oil everywhere. Other than that check the pump I've also had one split at the drive end or has Dutch mentioned poss even loose .I'd start there Best of luck BobH
Title: Re: Failure! Oil pump I think...
Post by: alanp on 02.08. 2012 11:17
I know this sounds stupid but make sure that the gauze filter plate is in the correct orientation so that the suction pipe fits through the hole and is not pressing against the gauze. If it isn't right bits of muck/sealant/fluff etc, especially after a engine rebuild, can build up on the gauze at that point and restrict suction. Guess how I know this!
Title: Re: Failure! Oil pump I think...
Post by: Black Flash on 02.08. 2012 12:45
Hi;
I think alanp is on the money! I did the same exact same thing with the same indications as you have. I don't think you will have hurt the motor if you didn't run it until the oil tank was empty. Mine took a couple of hundred miles to block the pipe and has now been fine for several hundred more. Gary


EDIT: I had installed the SRM screen upside down but in the correct orientation but it still partially blocked the pipe. Gary
Title: Re: Failure! Oil pump I think...
Post by: Hubie on 02.08. 2012 13:12
I was going to leave it and go to bed but I couldn't help myself!  I removed the sump plate and sure enough I had the strainer upside down so that the pickup was about 3/8 away from the hole and there was a tiny bit of gasket sealer right where the pickup was pressing against but enough to almost totally block it  *angry*  I cleaned the strainer and sump plate down with petrol, blew it all out with the airline and have run the bike for 20 minutes with fresh oil in there.

Oil coming back perfectly to the tank and not a dribble from the breather.  All is well again, that is after some of the oil that got past the rings gets cleared out of the pipes  *smile* and the motor feels fine.

Thanks to all for the help!
Title: Re: Failure! Oil pump I think...
Post by: duTch on 02.08. 2012 14:07
Too easy,- live 'n learn hey?
 Hope it stays good hubes, happy trekkin', cheers duTch
Title: Re: Failure! Oil pump I think...
Post by: chaterlea25 on 02.08. 2012 21:34
Hi Hubie and All,
Well done on getting it sorted  *smile*
A couple of years ago I fitted a SRM sump plate to a B32 single,
After a few hundred miles it started to wetsump badly  *sad2*
The magnet on the sump plug was strong enough to keep the ball in the pickup pipe firmly closed  ???? ???? ????
Also on the single cyl BSA's mount the plate with the plug farthest away from the pickup
I replaced the magnet with a less strong one, and all is well
HTH
John
Title: Re: Failure! Oil pump I think...
Post by: bikerboy on 03.08. 2012 02:59
I will add that I have never known an A10 oil pump to fail personally
Title: Re: Failure! Oil pump I think...
Post by: chaterlea25 on 03.08. 2012 21:25
Hi All,
Bikerboy, I have *sad2*
My brothers SR went terminal due to the degridation of the poxmetal alloy of the pump
 *ex* *ex* *ex*
John
Title: Re: Failure! Oil pump I think...
Post by: Stephen Foster on 04.08. 2012 08:53
Hi Hubie and All,
Well done on getting it sorted  *smile*
A couple of years ago I fitted a SRM sump plate to a B32 single,
After a few hundred miles it started to wetsump badly  *sad2*
The magnet on the sump plug was strong enough to keep the ball in the pickup pipe firmly closed  ???? ???? ????
Also on the single cyl BSA's mount the plate with the plug farthest away from the pickup
I replaced the magnet with a less strong one, and all is well
HTH
John


Some sort of genius to suss that out John !!
My word ..id never in a million years have twigged about the magnet !

Steve ..
Title: Re: Failure! Oil pump I think...
Post by: Topdad on 06.08. 2012 10:24
Hi Hubie, glad you sorted it. Re Bikerboy I have had a pump fall apart as per Johns post and have kept the remnants to remind me ,I'll post a picture ,not a pretty sight, regards Bob.
Title: Re: Failure! Oil pump I think...
Post by: Hubie on 09.09. 2012 21:38
Back again chaps,

It seems that I did do some damage when I had this recent little problem.  I have detected a big end knock at low idle so shall have to pull the motor down and see what damage there is.  Not happy about it but it happens I guess  *problem*

Cheers,
Hubie
Title: Re: Failure! Oil pump I think...
Post by: A10Boy on 02.10. 2012 17:22
Have you stripped the motor yet?

If not I would suggest you check the cushdrive nut is tight and the splines are good. I had a similar rattle and it was worn splines. Rebuilt it with a better crank and all was good.

Regards
Title: Re: Failure! Oil pump I think...
Post by: BSA500 on 05.10. 2012 08:45
Just to say as well my pump failed on the A7 just after a full rebuild. Luck would have it I was just slowing for a junction and she locked up. Only damage was the timing side bush and of course a knackered pump.
Title: Re: Failure! Oil pump I think...
Post by: Hubie on 06.10. 2012 07:54
Hi Chaps,

The bike has one of those bob newby racing clutches in it.  Turns out there was alot of play in the drive side main bearing.  Everything else was fine.  I am wondering if I originally had too much tension on the clutch belt and it pulled too hard on the bearing or the bearing was no good to start with.  Either way, new parts are on the way and she'll be back on the road soon. 

I am going to see if a piston specialist can reduce the compression on my pistons (8.5:1) to 7.25:1 as well.  Should be smoother and less vibratey!

Cheers,
Hubie.