Poulon Pro Chainsaw Carb Adjustment

Hi Everyone,

I've noticed a lot of carb adjustment threads here, but I'm having no luck. I hope ya'll can help me out. I have a Poulon Pro 4218AVX.

My chainsaw started acting as if it was out of fuel. It would idle, but going full throttle to cut a tree down it would bog down after 30 seconds and then die.

I noticed the in tank fuel filter had seperatred from the gas line. I ended up removing the engine from the case to get access to the fuel line. I ran two new fuel lines (supply and return) to the tank and installed a new fuel filter. Cleaned and reinstalled everything. I also installed a new spark plug and air filter.

So I attempted to start it. It would idle ok, but anymore than half throttle would bog down and die. Using the primer bulb, fuel is getting into the carb and flowing through the return line. So I bought the carb adjustment tool.

Following the directions somewhere else, I backed the Idle and High screws out till they were barely seated. Half turn on the idle till it would start. I screwed the idle all the way in and it never even tried to catch. I even removed the spark plug and grounded it to the head to see if there was spark.

Then I found the directions here. Screwed both idle and high in till lightly seated, back out 1 1/2 turns on the idle, 2 1/2 turns on the high. I've messed with that idle screw screwing out 1/4 turn each time for about 15 minues. I'm tired from cranking that dang chainsaw getting nothing.

What am I missing? I'll apologize now if this was covered somewhere else but I'm out of ideas.

Thanks,
Tim

 

Welcome to the forum.
I have the same brand of saw (not sure model) and noticed the same issue the last time I cut a tree with it.
Thought it was out of fuel and noted that there was a pretty good vacume on the fuel cap when I opened it to check (could hear air rush in).
The last time I used it (to cut some old planks), I had filled the tank and it didn't bog at all. I should note that being planks, I wasn't really running it too long per cut.

Did you notice any sort of vacume or pressure when you opened the fuel cap?
I am thinking the return line in my case is the issue.


As for your carb settings, when you say barely seated, I'm assuming you mean all the way in?
I've only had to really play with one carb (4-stroke snowblower) and the turns you are talking about sounds about right from fully closed.
Turn the idle and high screws all the way in, and back them out the turns you had mentioned. That should be a decent starting point.
These small engines are tough to really tune from what I have seen.

 

Try starting with both mixture screws 1 or 1 1/2 turns out. From there, set the idle speed screw and low speed screw for good idle, then set the high with the engine revved up. Set it to the point where the engine races the highest, then back it out a bit more until the engine gets a flutter to it. If it won't adjust like this, you probably need to clean the carb. It's common to need to clean the carb when a fuel line breaks. It picks up pieces of the crumbled line, dirt from the tank, etc...