New To Compression Testing

[pyromaniac guy]

ok, i'm pretty much new to everything. now, long story short, i need help. i got a stihl 031av off of ebay and want to use this saw as my guinea pig.

i want to clean it up and get it running again. it looks like whoever had it took relatively good care of it. i am just trying various things with this saw. i bought it to tinker with.

so, i bought a compression tester from baileys. i understand all the directions and procedures on the back of the box, but i do have one question:

do i have to run the saw for 15 minutes before it test compression? i have not tried to start this saw yet, and as of now it is dry on fluids. can't i just hook up the tester and try it? or will that ruin something i am unaware of?

thank you for your guidance...

 

[Lakeside53]

Just hook it up... make sure your ignition switch is off. Test it cold, test it hot, but just test it... You'll figure it out.

 

[2000ssm6]

pull it until it reaches max psi

 

[Cam501]

pull it until it reaches max psi

031's are EVIL!! ...our tech's cringe when they see one cause usually they end up calling the customer having to tell them them they can't get the parts they need, and then they hand the phone to me so i can get yelled at when i offer them a mail order company that deals in obsolete stihl parts. and by the way, I'm totally not tryin to discourage ya from using the 031 as a guinnea pig....just ranting

 

[Lakeside53]

I fix about 5 per week... every week... fuel, carb, ignitions... There is a stack of 031/32 out here... Almost all of them run just great when done. Average bill is around $100 - $125...

 

[pyromaniac guy]

i was originally looking for something that i knew i could still get parts for, like an 026 or something. but then this one came up and it was too good an offer to pass up.

i'll give the tester a rip this weekend and let you guys know how i make out...

 

[Cam501]

I fix about 5 per week... every week... fuel, carb, ignitions... There is a stack of 031/32 out here... Almost all of them run just great when done. Average bill is around $100 - $125...

where are you finding ignition parts? cause we can't get em through stihl anymore.

 

[Lakeside53]

We can buy points (rarely needed), and condensors (often - but only once in a typical lifetime). If the electronic module fails in that version, we just snip the wires and mount a Nova module. Coils rarely fail, and if they do, we get them from our own carcasses (we trade in a LOT of saws, dead or alive) or from cheapstihlsawparts (just up the road from us).

Rewinders are more problematic to find, but we just buy used widers in advance of needing them (just got 5 in).


I'd guess about 1/3 of our service work is old saws (pre-1990). We do a lot of old 015, 011, 028WB, 031, 032, 041, 056 (less now) etc... and occassionally some real gems... like 90 etc. Luckily we have a complete library of all the old service manuals and tech notes. Old saws keep old minds nimble.

 

[RiverRat2]

sweet saws!!!!!

i was originally looking for something that i knew i could still get parts for, like an 026 or something. but then this one came up and it was too good an offer to pass up.

i'll give the tester a rip this weekend and let you guys know how i make out...

fixed one a few weeks ago was brought in and had been torn down over a year ago was sitting @ the local lawnmower guys shop,,, He told th customer it was shot. we presssure/vac. tested the crankcase compression was 150 on 4 pulls,, had no spark,,,,checked igniton points found not to be opening, set gap correctly,,,,,fired on the second pull!!!!!!! change out leaky fuel cap replace air filter retuned carb I think it was around 100. repair ticket...mostly labor piecin it all bac together????????????????? Go figure