Engine done about 1800 miles since rebuild

[Topdad]

I can see it now , Daily Mail headline .... wonder cure for arthritis ...use straight 40 motor oil as recommended by the BSAA7 and A10 forum  members

[chaterlea25]

Hi Bikerboy,
If the rotating breather cork washer is not "compressed" enough it may be possible that crankcase pressure is building at higher speeds ???
I have found that the corks can compress and loosen over time,
If you remove the outer timing cover see if you can rotate the breather sleeve (a little within the confines of the fit of the driving peg) with your fingers
If you can its too loose 

John

[trevinoz]

I would be inclined towards the ball in the pick-up having stuck closed.
Another possibility is the oil draining from the scavenge pipe and the pump losing its priming.

[bikerboy]

Charterlee

Its not the cork for sure if anything I would suspect that of being marginally tight.

I have got an external anti sump valve on it temporarily just for test purposes and whenever I check it I take the lid off kick it over and as soon as it starts the oil is returning. I have also checked it virtually every time I have got home (barring that night as I said) and there has been a healthy return every time.

There is a guy in havant thats rebuilding oil pumps at a reasonable price includign using an alloy body so I am going to get one of them anyway as a matter of course and I am definitely changing the oil pipes. Once thats done I will try to hold it at a higher soeed for 25 or 30 miles to see if I have a repeat of the problem.

Its a bit bizarre cos in my foolish youth when we had no money and parts were cheap I bodged many an A10 engine, one I remember I left a compression ring out cos I could not get one and was going away, yet I never got anywhere near the trouble I have had with this one and I have lavished £1000's on it lol

Somewhere there is a lesson to be learned there no doubt

[bikerboy]

Well for those interested so far this bike has behaved immaculately. Starts fine, runs great, smoking problems gone and still no oil blown out again.

Baffles me

[Klaus]

Well for those interested so far this bike has behaved immaculately. Starts fine, runs great, smoking problems gone and still no oil blown out again.

Baffles me

Sometimes bike will be baffling, the same way as woman.

Everything with wheels and tits can cause problems

cheers Klaus

[muskrat]

Fingers crossed for you bikerboy.
Klaus, good to see that expression is universal. Down here it's " if it's got wheels or tits it'll give you trouble and cost you money).
Cheers

[bikerboy]

Just to totally end this thread I can safely say now that all problems are cured.

Its been well over a year since the last comment on here and the bike has done 8000 miles since without any problems as such.

Yes a few nuts and bolts have vibrated off but it runs like a dream.

Thanks everybody for your suggestions on the problems and without a doubt the problem was the pistons. The oil problems after were of my own making. It had wet sumped and I never realised it. I topped the oil up and of course when the oil was dragged out of the sump it was over filled and all flew out of the turret in the oil tank.

The bike is a total joy and goes like the clappers 

Just one thing, anybody that suggested I was running in too slow really does not know me at all 

Had you have said "ease up you idiot you are running in" you might have got it right 

[cableguide]

Hi Bikerboy,

Just wondering what ur final thghts are re the oil. Does it now look like it was the oil pump after all..or is it still to difficult a problem to put ur finger on.
My A7SS still puffs a bit after new guides, valves, a resleeve and NOS Hepolites...so frustrating.