What is an average compression number on a used Stihl 200T?
200T average used compression psi?
- Thread starter jeffbecky1
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airframefixer
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Make sure your gauge has a schrader valve on the hose end.
Otherwise 160ish for a 200 and 150ish for an 020T.
If you're seeing less than 130, confirm your gauge has the valve on the hose end, if it does, then in order of severity following a pressure vac test.
1)new rings if piston is clean.
2)New rings and piston with cylinder cleaning base gasket. Check intake tract.
3)New rings, piston and cylinder base gasket. Check intake tract.
4)New rings, piston, cylinder, seals, and might as well do bearings, check intake tract
Otherwise 160ish for a 200 and 150ish for an 020T.
If you're seeing less than 130, confirm your gauge has the valve on the hose end, if it does, then in order of severity following a pressure vac test.
1)new rings if piston is clean.
2)New rings and piston with cylinder cleaning base gasket. Check intake tract.
3)New rings, piston and cylinder base gasket. Check intake tract.
4)New rings, piston, cylinder, seals, and might as well do bearings, check intake tract
The post with 150 would be about right.
What reading do you have on yours?
It's at about 120, but, still runs good. I was surprised to see it that low.
Well how do you know the gauge is accurate? Did you keep pulling it over until it stopped rising? Have you tested the gauge in another saw? If its 120 its time for new crank seals, piston and rings. Not very expensive at this point.
Using a tester with a Schrader on the end of the hose, 150 is well used but still working well, 160 on a machine with less hours, 170 is about the best with the base gasket taken out and around 200psi on a ported one with the base gasket removed.
It's a Harbor Freight gauge. I pulled until it stopped rising
At 120 psi, it would be unusual for the engine to run, perhaps a larger bore engine may but an MS200, if it did run would never restart on a warm engine. Try a known good saw with the gauge. The gauge should have a Schrader valve with an extremely low spring rate usually used on gas sniffer devices. On many gauges used in the car industry, they are fitted with higher rated valves and don't read the correct compression on small engines.
Can you adapt it to your compressor line and compare it to that gauge if you have one? Or test another saw?
I have a strong running 200t with 127psi tested on two good gauges. I have new rings on order but it has run strong for two years with that reading. Sure I would like it to be 150-160 but...... It runs good the way it is, actually stronger that my low hr 201t.
When you swap out the rings, make sure you get a good look at the skirt wear...pricing a piston kit and just a set of rings is very close here stateside ( no idea AUS). You are already past the hard part of the rebuild, might as well finish out the top end, heck, seals are easy once it's on the bench too.
Here is a pic of one I ripped down last night. It had 170 lbs of compression and ran pretty good or so it seemed.
Any guesses as to what did this ? I already know for a fact.
man I wanna say "no filter" or FOD ingestion.
Why you think that?
both sides look scored. don't see too much oil/carbon buildup. looks too clean for a "straight gas" job...
bearings give out ?
now you got me thinking seals gave out.
Dont be fooled by the oil you see I put that there . Dirt ingested will get the intake side very heavily. But keep going.
