The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => A7 1946-1950 => Topic started by: pdg on 10.12. 2016 20:35
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Hello everyone,
For the first time, I'm attempting to undo the feeler gauge access plugs in the rocker boxes of my A7 Star Twin. As you will all know, these have a 3/4" long slot, for a very large flat blade "screw driver". Despite using my largest screw driver (with a wrench), I can't budge them.
I've found a TIPCO 3/4" WIDE DZUS SOCKET 3/8" DRIVE online. Is this the right thing to use to undo the plugs?
Many thanks, Peter.
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G'day Peter.
That would do the job. Also for the tool box lid screw.
Cheers
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Many thanks.
Regards, Peter.
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Hey mechanics, most of you probably already know this, but here goes anhyoo, (for those who may not know)... In the U S where I am, my Impact driver nose piece , that holds the type driver you are going to use, pulls right off, and then is a 3/8 ratchet drive, for far more leverage. Now for you U K and metric folks, I do not know if this translates over to metric, or Whitworth, or any European tools, when you take off the driver piece, and use your ratchet handle. The beauty of this is, (if it translates for you) there is no heavy pounding, as in a Impact driver, that can damage AL - U - MINIUM, Heh, Heh, Heh However the leverage you can get is phenominal compared to a screw driver handle. You still must use due dilligence care to stay in the slot though, to avoid falling out of same, and gouging the metal.
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Gees bill, is everything in the USA made cheaper.
My old impact driver has a 1/2 square drive head
And like you it gets used as a ratchet screwdriver quite regularly.
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Peter, these plugs have been known to grow together with the rocker box and too much force can take the plug along with the rocker box thread.
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Ah, that sounds very bad. I assume penetrating fluid may be a good idea? If not, leave them and assume the valve clearances are acceptable?
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I would be inclined to do the job on the bench with a bit of heat and penetrating oil. That means removing the bloody things and stripping them.
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Many thanks. I've got the tank off already, so will probably be able heat them with the engine in place. I'll use a gas torch on a low setting.
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After struggling with the old / original plugs for a long time, I got some new ones with a HEX head on them. Now I can use a spanner (think it is 5/16W if memory serves me correctly - maybe one bigger) which makes life so much easier.
They are available here on the Draganfly website - http://www.draganfly.co.uk/index.php/accessories-a-misc/product/14657-
Part# 67-66 Feeler gauge access plug, alloy - A7/ST 1947-49.
Not that cheap when you have to replace all 4 in 1 go, but have solved all the old problems that everyone suffers from.
I fitted them with a copper washer and have not had a problem or oil leak since. Image attached as they sit on the rockers.
Hope that is useful to some of you.
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Hi Craig,
Yes, I saw those and had the same thought. Where did you get the copper washers from?
Regards, Peter.
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Copper washers - you can get assortment box just off amazon.
of if you only want to buy singles then try - http://www.custom-fasteners.co.uk/
http://www.custom-fasteners.co.uk/washers-c102x2384235
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Copper washers - you can get assortment box just off amazon.
of if you only want to buy singles then try - http://www.custom-fasteners.co.uk/
http://www.custom-fasteners.co.uk/washers-c102x2384235
Useful link. I've copied your text to the forum 'Suppliers' pages *smile*
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Just curious, and slightly off, but are these caps/plugs/whatzits the same thread as the oil tank cap, primary cover inspection cap/ *eek* pre-unit triumph 650 valve cover cap *whistle*... *????*
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Butyl O rings will work better then copper washers.
They will seal better , prevent the bolts from vibrating loose and require far less pressure so it will be easier to remove them in future.