Gas line routing.

[humphrey1989]

I have a Poulan 2450 chainsaw and need to know what the gas line setup is. What I have now is (If you're looking at the chainsaw from above and standing behind it) the hole at the top right, which has a large line in it- goes to the bulb and then a small line goes from the bulb to the bottom left of the carburetor. The hole at the bottom left has a small line that that runs to the top right of the carburetor. The small line running from inside the tank to the carburetor directly has the fuel filter on it.

Is this correct?

 

[ILENGINE]

Sounds about right. Poulan has a wierd fuel line routing scheme. Small line from fuel cap side of tank, under carb, to fuel pump side of carb. Metering diaphragm side of carb to short plug on primer. Long plug on primer back under carb to tank on side opposite fuel cap.

 

[humphrey1989]

Will not idle

I am almost certain I have it correct. I watched a youtube video to make sure. Anyways, it not starting was a problem with the carburetor, I forgot I had taken the diaphragm out of that one. So I put on another complete carburetor and started pulling. I was able to get it to start but will not stay running unless I have the throttle on full and there is a lot of white smoke that pours our the exhaust.

Heads up to anyone putting together their chainsaw. Make sure to tighten the best you can the clutch cause trying to get this one to start, it flew off and separated- gone for ever it is in the grass.

 

[humphrey1989]

So on this other carburetor I have installed. Should a small amount of gas be coming from the high/low adjust screw holes? Screws are in but gas is coming out when primer bulb is pressed.

Metering diaphragm side of carb to short plug on primer.

Should the metering gas line be in the gas or just at the roof of the tank?

 

[ILENGINE]

If the primer is pushing fuel into the carb instead of pulling fuel through the carb, and back into the tank, reverse the lines on the primer. The return line from the primer can be either at the top or down inside the tank a little ways.

 

[humphrey1989]

Hey thanks buddy!

I got to messing around to make sure everything was still here on the carburetor and found that it is missing some seals/o-rings on the high/low needles.

Parts 4,5,52,53

Rebuild kits do not include the parts, where could I get these?


~ED~

I changed the lines around. Now the primer bulb pulls gas from the tank thru the carb and then pushes it into the tank.

 

[ILENGINE]

The easiest way to get those parts would be to rob them off another carb. Are you sure that the carb that you have uses those parts. With the price of the carb on most poulan chainsaws, it isn't worth spending much money or time on the carb. The carb for most of the poulan saws runs around $28.

 

[humphrey1989]

No I am not entirely sure. I have two carbs though, I know for sure one does cause when pulling its high/low screws I had seen them which made my look at the other. I am trying to figure out why this will not start- It is just frustrating.

 

[ILENGINE]

It could be the case where you are dealing with low compression (under 90 psi) or a scored cylinder. Remove the spark plug, and take a light and shine into the hole, and look at the cylinder walls and make sure it is smooth with no deep scratches, or gall marks.

 

[humphrey1989]

Pulled the spark plug and check the inside. So smooth looking. I tried starting it some more and noticed that its getting harder to pull the rope.

~ED~
As I mentioned, pulling the cord was getting harder. Only way to release pressure was to remove the spark plug which allowed for free pull of cord. Anyways, here are some pictures.

Gallery: Poulan Chainsaw - Imgur

I hooked up some test lines and bulb for the carburetor and attempted to simulate normal primer action (as seen in this video: https://www.youtube.com/watch?v=uCC1qO75zDk ) It wasn't pulling gas through that carburetor. Attempted to push fuel through the pump side and wasn't able to.