What am I doing wrong? Compression testing

[rxpx40]

Is this saw now your problem ?

No. I did not buy it. Still in the market for a saw over 50cc. I see you are also in Central Texas- whereabouts?
Chris

 

[angelo c]

I just did one a week ago that still ran but very poorly. Rings were stuck in the piston as well. Free'd them up with the deep fryer and all is well. Was an old 162se thin ring.

Shane, you're gonna have to expand some on the "deep fried" piston rings...I spent many years in kitchens but am only familiar with frying "onion" rings....not piston and "rings" ...

I hear in the "south" they deep fry everything...ring dings, Oreo cookies, ice cream ect..

 

[rxpx40]

I have a feeling you are using an adapter that is increasing the combustion chamber size. The valve for bleeding off pressure is no the Schroeder valve either. A compressor can overcome the added area of the adapter but a saw be tested cannot. Some of the thin ring saws would almost lose all tension on the cylinder walls over time and they still blew higher then 35psi. Over 100psi actually.

There's food for thought...
Let's see if I understand where you are going with this. You claim the gauge used *must* have the shortest hose possible or else it will increase the volume of the tested compression? It seems to me that regardless of the volume, if I keep applying small bursts of the same pressure (ie 50cc @ 150 psi) then a volume of 200cc's will take at least 4 pulls to achieve 150 psi. Hence the reason we pull until the gauge stops rising. Does this make sense?
I'm not trying to start an argument, trying to comprehend why I'm getting a low reading on a saw that could be good. I've seen some pictures here where guys are using fairly long hoses on their saws with a better reading than I am getting. I am starting to wonder if the quick connect adapter may be giving me some grief.
I am looking at another saw tomorrow. I will hear this one run. Then I will put my tester on this one too. I have to figure this out.

 

[Guido Salvage]

I hear in the "south" they deep fry everything...ring dings, Oreo cookies, ice cream ect..

Hog intestines and young bull testes as well...

 

[lone wolf]

There's food for thought...
Let's see if I understand where you are going with this. You claim the gauge used *must* have the shortest hose possible or else it will increase the volume of the tested compression? It seems to me that regardless of the volume, if I keep applying small bursts of the same pressure (ie 50cc @ 150 psi) then a volume of 200cc's will take at least 4 pulls to achieve 150 psi. Hence the reason we pull until the gauge stops rising. Does this make sense?
I'm not trying to start an argument, trying to comprehend why I'm getting a low reading on a saw that could be good. I've seen some pictures here where guys are using fairly long hoses on their saws with a better reading than I am getting. I am starting to wonder if the quick connect adapter may be giving me some grief.
I am looking at another saw tomorrow. I will hear this one run. Then I will put my tester on this one too. I have to figure this out.

Just borrow another gauge from a friend a good one.

 

[cedarshark]

No. I did not buy it. Still in the market for a saw over 50cc. I see you are also in Central Texas- whereabouts?
Chris

Lampasas, about 60 miles northwest of Austin. I have a 261 Stihl that has been started one time but never seen wood if you may be interested. Send me a pm if you need details.

 

[cedarshark]

Shane, you're gonna have to expand some on the "deep fried" piston rings...I spent many years in kitchens but am only familiar with frying "onion" rings....not piston and "rings" ...

I hear in the "south" they deep fry everything...ring dings, Oreo cookies, ice cream ect..

Sounds like you been to the Texas State Fair...last year they deep fried beer. Year before was deep fried butter. Low cholesterol of course.

 

[cedarshark]

RPX. I bought an 044 couple months ago that had a new aftermarket kit in it but would not run. Perfect cyl and piston but would only throw 60psi. Just a sorry a/m kit. Your guage might be fine. That saw may be worn out or has stuck rings.

 

[angelo c]

Sounds like you been to the Texas State Fair...last year they deep fried beer. Year before was deep fried butter. Low cholesterol of course.

Lemme guess....beer batter the beer first, then deep fry it ???

 

[cedarshark]

Lemme guess....beer batter the beer first, then deep fry it ???

No, beer batter is strictly reserved for things run over on the highway to quell the tar and gravel aftertaste. Possums, armadillos and such.

 

[angelo c]

No, beer batter is strictly reserved for things run over on the highway to quell the tar and gravel aftertaste. Possums, armadillos and such.

Heck I thought that's what the Moonshine was fer...disinfecting your mouth so you can get the red dirt road dust out to taste the roadkill, ooops "fresh game"

 

[cedarshark]

Heck I thought that's what the Moonshine was fer...disinfecting your mouth so you can get the red dirt road dust out to taste the roadkill, ooops "fresh game"

I think you and I should hunt up a culinary forum to exploit our mutual sophisticated taste buds. Happy Thankgiving BTW !

 

[GrassGuerilla]

I keep reading that the schrader MUST be in the tip that screws into the plug hole. The comp tester I got from Baileys has it near the gauge end. And it seems to work. Shows my Homelite 450 at 195 psi.

 

[sunfish]

I keep reading that the schrader MUST be in the tip that screws into the plug hole. The comp tester I got from Baileys has it near the gauge end. And it seems to work. Shows my Homelite 450 at 195 psi.

I have the cheapo gauge from Baileys and it works fine.

 

[GrassGuerilla]

I have the cheapo gauge from Baileys and it works fine.

Agreed. And thus debunks the myth that the schrader must be in the tip. It must have an appropriate schrader.

 

[Big_Wood]

There's food for thought...
Let's see if I understand where you are going with this. You claim the gauge used *must* have the shortest hose possible or else it will increase the volume of the tested compression? It seems to me that regardless of the volume, if I keep applying small bursts of the same pressure (ie 50cc @ 150 psi) then a volume of 200cc's will take at least 4 pulls to achieve 150 psi. Hence the reason we pull until the gauge stops rising. Does this make sense?
I'm not trying to start an argument, trying to comprehend why I'm getting a low reading on a saw that could be good. I've seen some pictures here where guys are using fairly long hoses on their saws with a better reading than I am getting. I am starting to wonder if the quick connect adapter may be giving me some grief.
I am looking at another saw tomorrow. I will hear this one run. Then I will put my tester on this one too. I have to figure this out.

The only thing you need is a Schraeder valve in the very end of the hose. If you look at the tip a Schraeder valve is the same valve they use in a valve stem to inflate your vehicle tires. The hose can be any length as long as you have that but will take more pulls to top the gauge out the longer it is.

 

[lone wolf]

The only thing you need is a Schraeder valve in the very end of the hose. The hose can be any length as long as you have that but will take more pulls to top the gauge out the longer it is.

My snap on with a long hose tops out at 12 pulls .

 

[cedarshark]

I have the Craftsman with the 12" hose and adaptor set. I have yet to find a small engine that it would not fit. About 12 pulls is average to max it out.

 

[lone wolf]

I have the Craftsman with the 12" hose and adaptor set. I have yet to find a small engine that it would not fit. About 12 pulls is average to max it out.

Does it fit the small plugs 10 m/m I think on the Stihl 4 mix and if so what numbers you getting from them?

 

[cedarshark]

Does it fit the small plugs 10 m/m I think on the Stihl 4 mix and if so what numbers you getting from them?

I don't own a Stihl 4 mix but the adaptors will fit any saw I have ever owned and all weedeaters and blowers and 4 cycle stuff...tillers, lawn mowers etc. if a saw has less than 120, it gets torn down,although I have an older Echo 702 that runs well at 130.