Compression Test

Information relating to the Matchless G3 or AJS Model 16 350cc Heavyweight
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Paul350
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Joined: Thu Mar 25, 2021 3:23 pm
Location: Warwickshire UK

Compression Test

Post by Paul350 »

For no particular reason I used a compression tester on my 1961 Model 16 and was surprised! The result was 120psi. I expected less with a 7.5:1 compression ratio. Pressure rose to this after three kicks, throttle open. Any thoughts?
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Tommy RE
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Location: WEST MIDLANDS UK

Re: Compression Test

Post by Tommy RE »

Paul350 wrote: Thu Sep 30, 2021 4:11 pm For no particular reason I used a compression tester on my 1961 Model 16 and was surprised! The result was 120psi. I expected less with a 7.5:1 compression ratio. Pressure rose to this after three kicks, throttle open. Any thoughts?
You have a goodun?
Paul350
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Joined: Thu Mar 25, 2021 3:23 pm
Location: Warwickshire UK

Re: Compression Test

Post by Paul350 »

That's what I thought. Unless there is lots of carbon build up? Maybe I will check.
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clive
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Re: Compression Test

Post by clive »

Paul350 wrote: Mon Oct 04, 2021 5:45 pm That's what I thought. Unless there is lots of carbon build up? Maybe I will check.
If it is starting and running well, and you know you have good compression why on earth would you start fiddling with it?
clive
if it ain't broke don't fix
Paul350
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Posts: 26
Joined: Thu Mar 25, 2021 3:23 pm
Location: Warwickshire UK

Re: Compression Test

Post by Paul350 »

I agree , not going to fiddle, just get a new battery for my boroscope and stare down the plug hole!
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