Older Poulan help. Runaway saw

[Novice_65]

Hey everyone,

I am new to this site and I have spent some time reading over a lot of posts here and I know there is a ton of expertise. I found this old Poulan Pro 255 that my dad had owned but it was not run for about 20 years. I just opened it up last week and checked the spark (which is decent) and has okay compression (120 according to my gauge).

The fuel lines cracked as I took a look around and I replaced them and thought no big deal. I cleaned out the carb and reassembled. It starts very quickly now, the problem is what it is doing. I posted a video just to show. The thing races like I have never seen before. Which is the reason I took off the chain. I tried readjusting the high and low screws as well as the idle but it really has no effect at all unfortunately. I also cleaned out the area around them in case it was clogged.

From reading it is possible I could have an air leak? I am going to pull the clutch and check for broken springs but right now I am stumped on this and thought I would reach out for some help or advice on what to do next. I consider myself mechanically inclined with this stuff but I am definitely not real experienced. I also hope this is posted in the correct section. Thank you all for your time.

 

[Goinwheelin]

Welcome to the site.

Not familiar with the 255 but it does sound like an air leak, probably crank seals but best way to verify is with a vacuum/pressure test.

Ton of poulan info here and very knowledgeable folks. Might find your answer here
https://www.arboristsite.com/community/threads/niks-poulan-thread.98495/page-2800

 

[Bobby Kirbos]

+1 on crank seals being the most likely cause of the problem.

 

[ChoppyChoppy]

Video isn't opening for me.

 

[scottr]

Same here , no video .

 

[medalist]

I concur on unmetered air.
I hate to make this suggestion but 60 years ago I had few tools like a pressure/ vacuum tester. I'd fill the crankcase with gasoline and look for seal seepage.
Probably considered dangerous (no seat belts or bicycle helmets then. and gasoline was .20 cents) so this is up to you.
Results are obvious.
Bear in mind there are other places a saw can leak and proper testing can save the hairline and offer definitive results.
Good luck with your project and I applaud your effort. New isn't always better and offers no satisfaction on a successful repair.

 

[medalist]

For the record video worked for me...showed up as download and needed to be opened to play. Typically on any other site I would be wary of this!
I wouldn't recommend running the saw like that... it's painful!

 

[jefflovstrom]

120 compression seems on the low end,
Jeff

 

[Novice_65]

Thanks everyone for all of the replies. Yeah I'm sorry about the video but wanted to show it the best I could. I will pull off the clutch and check out the seals and see what they look like. I just wanted some opinions on whether it is even fixable at this point. When I took it out of the case it was just sitting in old chain oil, not sure if that is indicative of anything.

Vaccuum and/or pressure test is something I have looked into trying as well but I'd have to borrow that equipment from a shop most likely. And just for what it's worth I only turned it on to capture the video, otherwise I wouldn't think of running it. Was afraid to lose my fingers. Thanks again guys

 

[Bobby Kirbos]

Pull the clutch and get the saw started. Spray some carb cleaner at the crank seal. If there is any change to the RPMs, you found your air leak. Doing the same thing on the flywheel side would answer the same question, but will be a bit more tricky to do.