Author Topic: A10 crankcase timing side questions  (Read 1403 times)

Offline scotty

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A10 crankcase timing side questions
« on: 27.02. 2009 00:23 »
Greetings all,

I'm in the middle of replacing all of the bushes on the timing side of my 55 A10 and I've noticed a couple of plugs/screws that I didn't take much notice of before  *conf*

The first one is adjacent to the main crank timing side bush. It has a slotted head and has been staked 3 times(see pic)
I'm wondering what its purpose in life is and if it's something I should remove/clean/service  ????

The second plug/screw is in the inner timing case just below the breather gallery(see pic)
What is this plugs/screws purpose  ????

Any wisdom is greatly appreciated

cheers

Scotty

Scotty
'56 A10 Red Flash
'54 B33
'98 HD FLHTPI
‘74 BMW R75-6

Online bsa-bill

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Re: A10 crankcase timing side questions
« Reply #1 on: 27.02. 2009 09:49 »
HI Scotty
The screw in your crankcase is probably the one that covers the non return valve behind the pump, one of two designed into the engine by BSA.
The one on your inner timing case blanks off the drilling for the breather, you can see the path of the air flow from the breather going up the case at about fortyfive degrees then it goes along a gallery at the rear of the crankcaes and exits through a hole pointing downwards behind the primary case, if you can get a finger down behind the rear of the engine and between the primary case you can feel the exit hole.

All the best - Bill
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Offline olev

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Re: A10 crankcase timing side questions
« Reply #2 on: 27.02. 2009 11:05 »
Gday Scotty,
Looks like I'm not the only one delving into the deep guts.
Behind that screw (the one near your timing bush) is your anti wet sumping valve which appears to be the cause of much grief and smoke.
 http://www.a7a10.net/forum/index.php?topic=848.0
ps. for interest only - its no longer for sale. I think fido ate it along with one of my new sludge trap plugs.
I bought a new spring & ball bearing thingy from the UK. The postage was more expensive than the item which I was disgusted with.
I can get a better quality spring out of a biro. It takes a hell of a lot of effort and money to get to this deep into a motor and I would have been happy to pay 3 times as much to get a decent stainless spring rated for the job. The plug is not easy to get out. I drilled a few 1/16" holes in line with the slot, flogged a screw driver into it and wound her out. Guinness helps.
Scotty, take a mugs advice and change that valve now that you are in there.
and If you find someone who sells a decent spring, please let me know.
cheers

Offline scotty

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Re: A10 crankcase timing side questions
« Reply #3 on: 28.02. 2009 01:34 »
Bill...thanks for that info. I loosely assembled the crank cases and inner timing case and blew compressed air thru breather gallery and felt air coming out on the drive side of the crank case where you indicated.

Olev...I poked around at the backside of that screw and I can see/ feel the ball on the spring...I'll take your advice and get into that non return valve assembly and replace it while it's accessible and i'll keep you posted on the quality of replacement parts.

Thanks to you both for the wisdom  *smiley4*


Cheers

Scotty

Scotty
'56 A10 Red Flash
'54 B33
'98 HD FLHTPI
‘74 BMW R75-6