Compression pressures?

[Ceebl]

Hi, Does anyone know what pressure you should read on a compression Gauge on a sv650sk1? Many thanks guys (it's one of the testers that fits over the spark plug hole, not very knowledgable about compression testing il admit but the guy doin it is and needs the figures :D )

[5hort5]

According to the Haynes bible it is:

Standard .......................................... 213 psi(15.0 Bar)
Service Limit ..................................... 156 psi (11.0 Bar)
Max. Difference between cylinders ........ 28 psi (2.0 Bar)

[5hort5]

Out of curiosity what does this tell you when you know the figures?

[Ceebl]

Aparently from what I remember of that convo if it's low u put some oil in the cylinder, if it's still low it's the rings and if its normal after that then it's the valves! Might b wrong way round but that's the gist of how to problem solve!! Sounds logical cuz if the pressure still low then the oil has escaped past knackered rings and if it's fixed then the pressures escapin past the valves...

[yorkie_chris]

How healthy the engine is with regards how well the rings are sealing.

You can get misleadingly low numbers with CV carbs. What problem are you having?

[5hort5]

ok - so if it wasn't very good what could you do it fix it? New rings or something more drastic?

[Ceebl]

Small lack of power n some smoke whn throttling, don't kno if it's burning oil or rich petrol tho as I hav a weepy clutch cover which accounts for oil and I hav recently discovered my choke is sticky ( it got progressivly worse over last few days from spitting on idle to now having what sounds like 1 plunger on full all the time) however my tappets sound noisey and god knows when this wee engine had a clearance check last so I'm going to do a test while I'm in there changin the plugs and sortin the choke anyway, no harm done and is costin me nothin!!

[flymo]

you need three important things for an engine to run, fuel at the correct mixture, a good spark at the correct moment and compression.

low compression can indicate worn rings, leaking valves, blown cylinder head gasket etc. The 'oil' test can be used if you have low compression readings, oil can temporarily help worn piston rings seal and increase the compression readings. The oil wont fix anything but simply confirm that worn rings might be the issue.

[Ceebl]

you need three important things for an engine to run, fuel at the correct mixture, a good spark at the correct moment and compression.

low compression can indicate worn rings, leaking valves, blown cylinder head gasket etc. The 'oil' test can be used if you have low compression readings, oil can temporarily help worn piston rings seal and increase the compression readings. The oil wont fix anything but simply confirm that worn rings might be the issue.


That's the one! I got it the wrong way round jus cuz I was thinkin if u put oil in n rings wer knackered then the oil wud dissapear!