Author Topic: A10 Small journal sludge trap thread size?  (Read 2098 times)

Offline cosmikdebriis

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A10 Small journal sludge trap thread size?
« on: 03.04. 2012 18:58 »
I've just spent many a happy hour drilling and generally destroying the sludge trap screws so that I could clean the trap out.

Couldn't believe the amount of gunk in there, it was almost solid with crap. god knows how any oil got through to the big ends *eek*

Anyway, I want to clean up the threads in the crank before replacing the screws but can't quite make up my mind what thread they are. Looks like it could be BSP or possibly BSCY?

Anybody know for sure?

By the way. If anyone is thinking of rebuilding their engine but not bothering to clean out the sludge trap then THINK AGAIN... ;)

Online bikerbob

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Re: A10 Small journal sludge trap thread size?
« Reply #1 on: 06.04. 2012 09:18 »
Hi there. I was hoping some one else would have replied to your query by now as I do not have any accurate measuring equipment  but I have infront of me a plug from a small journal crank and it measures 5/8" outside dia which rules out 1/4 or 3/8 BSP and counting the threads it would appear that there would 20 threads to the inch which makes it a 5/8 cycle thread  but I would hope someone else could possilbly confirm my thinking. Good luck.

Online duTch

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Re: A10 Small journal sludge trap thread size?
« Reply #2 on: 06.04. 2012 10:08 »
I have a Large Journal, and it has(by my calculating) 11 threads@ 7/8"dia. which makes it BSF, but that's pointless in this case, but in your case 20 TPI according to the chart I have makes it BSC, as from 1/2" to 3/4" BSC had dual pitch 20/26. 7/8" has 20/24 TPI and 24 for 1"
 Don't ask me why, that's what the chart says- cheers duTch
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
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Offline cosmikdebriis

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Re: A10 Small journal sludge trap thread size?
« Reply #3 on: 07.04. 2012 18:04 »
Thanks guys, cycle thread (bscy) seemed the most likely.

I was going to make up my own so that I could improve on the design but ended up just buying some.

Offline BSA_54A10

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Re: A10 Small journal sludge trap thread size?
« Reply #4 on: 08.04. 2012 12:47 »
You should be able to find allen headed sludge trap bolts.
These are a better idea as they are a lot easier to remove.
Bike Beesa
Trevor

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Re: A10 Small journal sludge trap thread size?
« Reply #5 on: 08.04. 2012 17:26 »
Oh yeah I forgot to say that I'm pretty sure SRM have them, cheap as buggry(ish)http://www.srmclassicbikes.com/catalogue/index.php?target=categories&category_id=63

 There you have it gbp4.11 each x2 (I don't have the gbp button) too easy
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Offline Gasket4450

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Re: A10 Small journal sludge trap thread size?
« Reply #6 on: 04.06. 2012 17:58 »
Hmm...... this sounds like something I may have to do as well. I am trying to build an A7 Shooting Star virtually from scratch, having done the same thing with an A10 a couple of years ago ( can I put a picture up ? how do I do that, someone ? . Anyway, I have acquired a decent crankshaft, which apears to need only its first re-grind, but I was wondering how to remove the sludge trap plugs, which have been well and truly popped in ( 4 or 5 punch marks around each ). I am not worried about originality, so am quite happy to buy the new type, with allen heads, but have I got to destroy the old ones to get them out ?
Any advice from some of you Oracles out there would be most welcome.
Norman
1960 A10, alive and thriving. 1959 A7 living on borrowed time !

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Re: A10 Small journal sludge trap thread size?
« Reply #7 on: 04.06. 2012 21:05 »
 G'day Norm,
                 you may find they have been out before with that many punch marks. Using a 1/8 - 3/16" drill clean up each punch mark (doesn't take much) then use an impact driver to unscrew. Hold crank by flywheel in vice (soft jaws) and don't be frightened to give it a good belt.
 Pictures - When you start a new post or reply to one, under the main box see Attach box Browse (more att). Click browse find the pic and click on it. For more click (more att) then same again.
Cheers
'51 A7 plunger, '57 A7SS now A10CR, '76 XT500, '77 AG175 '83 CB1100F, '81 CB900F project.
Australia
Muskys Plunger A7

Offline Gasket4450

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Re: A10 Small journal sludge trap thread size?
« Reply #8 on: 07.06. 2012 15:39 »
Thanks for that, Musky. I have a well-used impact driver which has never let me down yet, and, as you say, I always believe in giving it one good, straight clout, instead of fannying around with it and tapping it gently. I'll let you know how I get on ( and keep you posted on what comes out of the trap ! ). I have the small journal six-bolt A7 crank, so I guess from this thread there will be no tube inside ?
               Thanks also for pic advice - however, I was meaning the pic that comes up with your details in the left margin on each post. I'm sure I read somewhere in the newbie joining instructions that I can put a picture on my profile somehow, but can't find my way back to the ' Welcome Letter ' !!! ( This is the bloke who's gonna put an A7 engine together, by the way.........ha ha ha!  *smile*)
Cheers mate, Norman
1960 A10, alive and thriving. 1959 A7 living on borrowed time !

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Re: A10 Small journal sludge trap thread size?
« Reply #9 on: 07.06. 2012 21:11 »
G'day Norm,
                click profile then forum profile info. Browse to select pic.
Cheers
'51 A7 plunger, '57 A7SS now A10CR, '76 XT500, '77 AG175 '83 CB1100F, '81 CB900F project.
Australia
Muskys Plunger A7

Online Greybeard

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Re: A10 Small journal sludge trap thread size?
« Reply #10 on: 26.05. 2018 21:21 »
You should be able to find allen headed sludge trap bolts.
These are a better idea as they are a lot easier to remove.
Ordered, from SRM

Online Rex

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Re: A10 Small journal sludge trap thread size?
« Reply #11 on: 27.05. 2018 16:49 »
I've got a feeling (after going through the same pain last year) that the small crank journal plugs are slotted head only, unlike the larger ones which are available in either slotted or hex'd.

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Re: A10 Small journal sludge trap thread size?
« Reply #12 on: 27.05. 2018 17:03 »
I've got a feeling (after going through the same pain last year) that the small crank journal plugs are slotted head only, unlike the larger ones which are available in either slotted or hex'd.
I've just ordered some hex, (small journal) ones from SRM. I needed to take out a mortgage!

Online Rex

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Re: A10 Small journal sludge trap thread size?
« Reply #13 on: 27.05. 2018 20:51 »
Wish I'd known this a few months back!