How to test a used saw?

[t_andersen]

Hi guys,

Suppose that you get a used chain saw power head in your hand and want to make an "acceptance test" to check how good or bad it is. Which are the things that you look at? Compression, clutch, ease of starting, scratches, cracks, rusty muffler, ...? Can we set up a check list?

Thanks

Tom

 

[Lawn Masters]

dirt or lack of is a good indicator of how well a saw is taken care of.
Also, check the crank bearings for any play, make sure spark is strong, fuel and air filters clean/new, that it idles properly, compression should be in the mid 100s range, around 120PSI is normal for a decent used saw. clutch slipping is not a good sign, which brings me to the sprocket, which should be checked for wear and tear.

Most of the time, a rusty muffler is an indication that the saw has been used heavily.

 

[Crofter]

1. Look for mismatched fasteners and washers, indicating possible stripped threads.

2, Ask if you can remove muffler to examine piston and cylinder for scoring.

3. Compression,

4. Good idle and accelleration

5. Examine saw for cracks, be sure to turn upside down, but consider scratches cosmetic.

6. Have a look at the bar mount area for cracks and apparent damage to mounting studs.

 

[Lobo]

1. Look for mismatched fasteners and washers, indicating possible stripped threads.

2, Ask if you can remove muffler to examine piston and cylinder for scoring.

3. Compression,

4. Good idle and accelleration

5. Examine saw for cracks, be sure to turn upside down, but consider scratches cosmetic.

6. Have a look at the bar mount area for cracks and apparent damage to mounting studs.

Ditto

 

[Justin Garrison]

What they said and make sure chain does not spin at idle, chain brake operational, chain tensioner works, if possible look at clutch shoes for excessive wear. How they keep their airfilter is how they keep their saw.

 

[glens]

You might also pull the plug and make sure the engine turns over smoothly and with no mechanical clatter, and maybe try to remember to see if all the flywheel fins are in place, and check the suspension for broken/torn bits.

 

[tony marks]

2 hrs in hard cut ,may not be something u could do.. but that would be my besttest as to what i thought of an saw.. in 2 hrs you will see hints of problems if they are there..
also you know if the saw actuall;y is what you wouyld enjoy using... this from a non mechanic.. i realize most wont let you give an saw for sell, this test.. but we are talking the best way to know.. imo.

 

[Mange]

1. Look for mismatched fasteners and washers, indicating possible stripped threads.

2, Ask if you can remove muffler to examine piston and cylinder for scoring.

3. Compression,

4. Good idle and accelleration

5. Examine saw for cracks, be sure to turn upside down, but consider scratches cosmetic.

6. Have a look at the bar mount area for cracks and apparent damage to mounting studs.

A few simple test if it pass this.
Hold it in the starter handel to test the compression.

When on Idle check the crank seals/bearings, by shifting the saw to left and right side. If it runs higher in RPM's set it down and walk away, Or use it as partssaw.

Test the Chainbrake.

Run it warm, and then stop it and test the comp again, also look for leaking oil, gas.

I think you have enough tips to get by.

 

[t_andersen]

Here's the compiled check list

Based upon the responses, I have tried to compile the check list below. Please comment if something is wrong. Thanks for your help!

GENERAL INSPECTION
A rusty muffler is generally a sign of wear
Check for cracks in housing
Check for damage to bar mounting studs
Is the chain tensioner ok?
Does the sprocket show signs of wear and tear?
Look for mismatched fasterners and washes, indicating possible stripped threads
Are all fly-wheel fins in place?
Any broken or torn bits in suspension?

FILTERS
Check that fuel and air filters are in good shape. Lousy filters are a sign of poor maintenance

IGNITION
Take out the spark plug and check that there is a strong spark

CRANK BEARINGS
Remove the chain and check that the crank bearings do not have excessive play

CYLINDER AND PISTON
Remove muffler to inspect that piston/cylinder do not have scoring

COMPRESSION
If you can measure it, it should be 120 psi or better
If not, hold the saw in the start handle to test compression
Check compression also when warm

TEST RUN
Check that the clutch is not slipping
Check that the chain does not spin at idle
Check that the chain brake functions
Check that the saw idles and accelerates well
On idle, check that the crank seals/bearings are ok by shifting the saw to left and right side. The saw should not change rpm
If possible, use it for two hour's hard cut