Author Topic: Compression test on a A10  (Read 1849 times)

Offline joecr

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Compression test on a A10
« on: 18.03. 2008 15:02 »
I'm about to do a compression test on my A10 plunger, can anyone give me  a round about figure for what the reading should be on a healthy engine? I've only had the bike a short time and the last owner put new pistons and rings in and it hasn't been run in yet. I would like to check periodicly to see how the rings are bedding in.
Thanks, Joe.

Online RichardL

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Re: Compression test on a A10
« Reply #1 on: 18.03. 2008 15:34 »
Joe,

Go to  topic "Measuring Compression" (pg. 4 under "Tech Topics") and you will get a whole lot of discussion on the topic.

Richard
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Offline joecr

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Re: Compression test on a A10
« Reply #2 on: 18.03. 2008 16:57 »
Oops, should have looked before I leaped, everything is there that I wanted to know.
Thanks, Joe.

Offline Big Nick

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Re: Compression test on a A10
« Reply #3 on: 18.07. 2013 16:51 »
after checking mine , its been standing for some time compression down to 80 or so to it's head a barrel off tomorrow and have a look
1932 500cc rudge
1936 500cc cotton pyton
1952 M20 with B31 motor
1952 Plunger A10
1954 New Hudson Autocycle
1962 A10
1982 BMW R100

Offline Big Nick

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Re: Compression test on a A10
« Reply #4 on: 19.07. 2013 12:40 »
ring gap on compression ring 25
1932 500cc rudge
1936 500cc cotton pyton
1952 M20 with B31 motor
1952 Plunger A10
1954 New Hudson Autocycle
1962 A10
1982 BMW R100

Online muskrat

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Re: Compression test on a A10
« Reply #5 on: 19.07. 2013 14:55 »
That's not too bad Nick. I've seen them running well with gaps bigger than that. Were you holding the throttle wide open when kicking over and at least 6 kicks?
My low comp '51 A7 shows 130 Lb sq in, the high comp A10 shows 175.
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7

Offline Big Nick

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Re: Compression test on a A10
« Reply #6 on: 19.07. 2013 18:43 »
thanks , i also check it out with my friend gary at srm but when i pour petrol down the exhaust port it is seaping past  so grid the valves in again the next stop. the only fun i had was getting the 2 bolts out at the front holding the head down . i did not replace them last time and the head are getting a bit round and all that heat a bit firmly fixed in place but with a bit of penetrating oil they came out
1932 500cc rudge
1936 500cc cotton pyton
1952 M20 with B31 motor
1952 Plunger A10
1954 New Hudson Autocycle
1962 A10
1982 BMW R100