Blower compression rating?

[kikori]

I am looking at a 3 year old lightly used stihl back pack blower tomorrow. I will compression test it.

If a good used saw would test 150 psi, should I be looking for something similar with a Stihl BR 420?

Anyone?

Thanks,

Eric

 

[sawinredneck]

Any two stroke, 125psi, is close to worn out, 150psi is a decent used machine, 175psi is a good running machine. Anything less than 125 on a two stroke, it's toast and hard to start. Walk away!
Four stroke, 50psi, it starts, but is worn out, 75psi, it starts good and is usable, anything above that, run it like you stole it!
There is NO comparison between two and four stroke, two stroke is ALL about compression, it doesn't work without it!

 

[kikori]

Excellent! Thanks for the response.

Now I will know what to look for!

Eric

 

[sawinredneck]

I try, you are welcome!

 

[MasterBlaster]

Yes, it's true

<see how I'm doing this?>

​

 

[Al Smith]

Blowers almost never wear out although they do get carb problems ,seals etc .Unlike a chainsaw though they almost never run hot,aren't subjected to the saw chips etc . They do get stepped on ,ran over by trucks ,fall off the back of same etc .

 

[Ax-Man]

Blowers almost never wear out although they do get carb problems ,seals etc .Unlike a chainsaw though they almost never run hot,aren't subjected to the saw chips etc . They do get stepped on ,ran over by trucks ,fall off the back of same etc .

Oh so true. I have lost two good blowers to trucks running over them.

 

[Ax-Man]

Any two stroke, 125psi, is close to worn out, 150psi is a decent used machine, 175psi is a good running machine. Anything less than 125 on a two stroke, it's toast and hard to start. Walk away!
Four stroke, 50psi, it starts, but is worn out, 75psi, it starts good and is usable, anything above that, run it like you stole it!
There is NO comparison between two and four stroke, two stroke is ALL about compression, it doesn't work without it!

Good post Andy. The compression numbers for four stroke small engines is right on. Funny how the numbers double when it comes to two strokes.

 

[Al Smith]

Oh so true. I have lost two good blowers to trucks running over them.

Yep,that wears them out in a hurry .