Tech said chainsaw is junk Scored Piston and Cylinder PoulanPro pr5020

[Blake_Otto]

There is a lot of information on how to fix scored piston and cylinder on the forum, that is not my question. Problem: saw all the sudden died when trying to warm up and died again when I actually put it in a log. So I looked at the piston and it is scored pretty severely (pictures below), I took the chainsaw to a tech and they said it would be pointless to put a new cylinder in and that I should simply buy a new saw and sell the old one for parts. Its fairly new and I take good care of my equipment, looking online a new cylinder is 40$ why cant I just pop a new cylinder in it? I am running a firewood business and will then need a new backup saw likely echo timberwolf 20in for around 400$. Obviously 40$ + time is cheaper then a brand new saw, what's the move?

 

[cookies]

your pictures are not working
if its that inexpensive then replace the jug/piston yourself and figure out why the scoring happened. ran lean? debris sucked in?

 

[ammoaddict]

You can replace it, but you need to determine the reason it scored in the first place or the same thing will happen again.

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[Blake_Otto]

your pictures are not working
if its that inexpensive then replace the jug/piston yourself and figure out why the scoring happened. ran lean? debris sucked in?

Alright I think I fixed the pictures, I also realize I posted in the wrong section of the forum so sorry for that. I've always used 89 octane gas with stihl oil 50-1 mix so I guess the problem would be debris getting into the cylinder or overheating. So if that is the case can't I just take the time to put in a new cylinder and the saw will do fine? Before the compression issue from the scoring there haven't been any other problems. Thank you for the help.

 

[Yukon Stihl]

Do you know how to tune your chainsaw?
Did you tune your chainsaw?
The Poulans are tuned right at the edge of burning down to meet emissions. That and 50:1 mix dosnt leave a margin for anything to go wrong.

 

[Blake_Otto]

Do you know how to tune your chainsaw?
Did you tune your chainsaw?
The Poulans are tuned right at the edge of burning down to meet emissions. That and 50:1 mix dosnt leave a margin for anything to go wrong.

No, I have never tuned the carb on the saw, from looking at the saw my thoughts are the problem with the cylinder comes from debris getting past the air filter into the engine (last picture) so if I replace the entire cylinder head and the filter there might still be dust in saw which will lead to the same problem happening again. I have little knowledge of small engines and haven't been able to find a way to avoid the issue happening again or how to clean out a saw that had a bad filter and now has debris in the saw.

 

[Yukon Stihl]

If you have never tuned it then my guess is that it was run to lean, plus marginal oil means goodby piston Unless you are pulling sand past the air filter ingestion of sawdust doesn’t take out pistons very fast.

 

[Yukon Stihl]

I have an old PM Canadien that was run for a long time without an air filter. There was sawdust and oil mixture baked on to the inside of the crankcase. The piston was wore but not scored

 

[cookies]

That air filter looks nasty...ever change it ? ever change the fuel filter? plug? ever adjust the carb after buying it? they are set very lean out of the box! I say rebuild it, replace the filters/plug, properly adjust the carb and giver hell. oh and run it at 40-1 not 50-1.

 

[Blake_Otto]

That air filter looks nasty...ever change it ? ever change the fuel filter? plug? ever adjust the carb after buying it? they are set very lean out of the box! I say rebuild it, replace the filters/plug, properly adjust the carb and giver hell. oh and run it at 40-1 not 50-1.

Awesome thank you for the help.

 

[ammoaddict]

Awesome thank you for the help.

The nikisil coating in the cylinders is pretty tough. You can probably clean it up and just replace the piston and ring. You will probably have to get the splined carb tool to tune it. You can wash your air filter in hot soapy water and let it air dry. I use 40:1 full synthetic and non ethanol fuel in every 2 stroke I own.

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[Blake_Otto]

The nikisil coating in the cylinders is pretty tough. You can probably clean it up and just replace the piston and ring. You will probably have to get the splined carb tool to tune it. You can wash your air filter in hot soapy water and let it air dry. I use 40:1 full synthetic and non ethanol fuel in every 2 stroke I own.

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I would love to use ethonol free however the closest place is 45 minutes away or I have to spend 15 for a gallon at home stores or my lawncare store its a problem.

 

[ammoaddict]

I would love to use ethonol free however the closest place is 45 minutes away or I have to spend 15 for a gallon at home stores or my lawncare store its a problem.

I have to drive 20 minutes to get it. I buy enough to last a few months and put stabil in it. It's all I use in my outdoor equipment.

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[Woodslasher]

@madhatte could you please move this?

 

[madhatte]

Moved to Chainsaws

 

[Jasent]

You may want to check your seals while your in it. It is cheaper to buy new saw if your paying the tech to rebuild it. If your capable of working on it rebuild it your self.

 

[sean donato]

No offense, but running a wood business with a homeowner grade saw is asking for disaster. Go grab up that echo you were talking about and toss the Poulan in the back of your bench and save it for a rainy day. Been down this road with a husqy 435. Just wasnt up to the task of firewood duty. Constant issues, till I got smart and bought a pro saw. Gave the 435 away to a friend that doesn't cut much and he's been very happy with it.

 

[RED-85-Z51]

Cudtomer brought me a poulan pro 42cc 18" saw that lasted a tank or 2 and scored the cylinder and piston. Whole top end was like 35 bucks but i figured 2 hours labor to clean it, disassemble, build and tune...and make a few bucks on parts, that's about 150 dollars which is what a new saw runs.

She said she would just buy another new one. So i said screw it ill just rebuild it for the experience. Its not easy, its a pain in the butt saw to work on, but it did run fine once tuned...ill never build another one

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[GeorgiaVol]

Cudtomer brought me a poulan pro 42cc 18" saw that lasted a tank or 2 and scored the cylinder and piston. Whole top end was like 35 bucks but i figured 2 hours labor to clean it, disassemble, build and tune...and make a few bucks on parts, that's about 150 dollars which is what a new saw runs.

She said she would just buy another new one. So i said screw it ill just rebuild it for the experience. Its not easy, its a pain in the butt saw to work on, but it did run fine once tuned...ill never build another one

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Yeah, the new strato poulans are a pain.
The older ones are quite simple though.

 

[Vintage Engine Repairs]

OP, just being frank with you - unless you’re going to pressure and vac test the saw before repairing it to confirm exactly what caused the engine seizure (I can’t see any pictures, but it’s not sawdust that caused a seizure I can promise you that) you’re wasting your time and money.

Us guessing at the issue isn’t going to help you either.

The reality of what you’ll quite possibly need (all prices are AM and using AM parts is asking for more trouble and problems)

Piston, cylinder, rings & C clips $40
Oil seals $10
Rubber lines $10
Carb kit $15
Fuel filter $5
Gasket maker $20
Pressure / vac tester $30-80
Patients $$$
Hours of your time $$$
Tune the saw correctly $$$

Depending if the ally has galled the crank shaft bearings you may need new ones of them too and possibly the small end bearing as well. - you won’t get much change from $200 and even some of those parts may have issues.

Rebuilding any saw is rarely worth it financially, it’s a labour of love. If you go into it knowing that it’s likly to cost more than a new saw is worth, then that’s a good place to start.

Then even after all this time and $200 or so, your saw may still have problems you’ll need to troubleshoot afterwards.

Now you can see that a new saw, with warranty isn’t that bad of an option after all.

As someone else said, buy a new one and save this for a rainy day. Either way, we’ll all be behind you to help you with the rebuild!