If I have an engine with the following specs, how many PSI should my guage read? or am I not providing enough information?
Displacement: 171.00 ccm (10.43 cubic inches)
Engine type: Single cylinder
Stroke: 2
Power: 15.00 HP (10.9 kW)) @ 7500 RPM
Compression: 6.8:1
Bore x stroke: 66.0 x 50.0 mm (2.6 x 2.0 inches)
If your compression is 6.8:1 - a compression test should read about 100PSI on a 4 stroke. But it's a 2 stroke so I'm not sure.
Grtechguy wrote:If I have an engine with the following specs, how many PSI should my guage read? or am I not providing enough information?
Which gauge?
6.8:1 is the ratio of the volume of the cylinder when the last port closes to the combustion chamber volume.
You're looking for at least 14.7 PSI x 6.8, so 100. You should get somewhat higher numbers if it's a reed or rotary valve engine due to crankcase compression.
What engine is this?
It's a Yamaha 175cc still mounted in the '80 DT175mx
Nashco wrote:Grtechguy wrote:If I have an engine with the following specs, how many PSI should my guage read? or am I not providing enough information?
Which gauge?
The one I use to get compression readings. reads 0-250psi. screws in the spark plug hole
100 PSI.
If you want more, check the crankcase seals and put in some new reeds.
dynamic vs static compression ratio is the curve ball here. This may help: http://www.dirtrider.net/forums3/showthread.php?t=152854
