Poulan Pro 405

[Willie2331]

I have a Poulan Pro 405 1990 vintage. Has a Walbro WJ20a carburetor and I put in a Walbro repair kit. Saw runs well and cuts really good, but the exhaust is a little smoky and I can’t get it to clear up. Is it normal for an older saw of this type ?

 

[Gullet]

@Mastermind has or had a 455 so he might know something.

 

[Lnk]

I have a Poulan Pro 405 1990 vintage. Has a Walbro WJ20a carburetor and I put in a Walbro repair kit. Saw runs well and cuts really good, but the exhaust is a little smoky and I can’t get it to clear up. Is it normal for an older saw of this type ?

Would think that it would clear up. What mix are you running? Do you have the high jet too rich? Could be burning up some old buildup also. Is there a screen in the exhaust, and does it look clear? If it had old fuel in it, the oil might have settled and gummed inside the tank. New fuel could be cleaning that out also.

 

[Mastermind]

I have a Poulan Pro 405 1990 vintage. Has a Walbro WJ20a carburetor and I put in a Walbro repair kit. Saw runs well and cuts really good, but the exhaust is a little smoky and I can’t get it to clear up. Is it normal for an older saw of this type ?

What oil, and what ratio?

 

[Willie2331]

Using Stihl HP Ultra 2 cycle oil, 50:1 mix. Non ethanol 90. Same as in my other saws, Poulan 295 and Poulan 4218 with no smoke issues. Exhaust screen clear. Can adjust and minimize exhaust smoke but no acceleration or power.

 

[Mastermind]

Using Stihl HP Ultra 2 cycle oil, 50:1 mix. Non ethanol 90. Same as in my other saws, Poulan 295 and Poulan 4218 with no smoke issues. Exhaust screen clear. Can adjust and minimize exhaust smoke but no acceleration or power.

Some of these Poulans don't use a case gasket....and sometimes the sealer fails allowing bar oil to be drawn into the crankcase and burned.

 

[fossil]

The 405 case is like the mid size P series Pioneers (P40, P41 etc) and they have a small plate which separates the oil and fuel tanks which is held in by some type of epoxy.
It's not unusual for the plate to fall out or leak which will allow the bar oil to mix with the fuel with the fuel in the tank.

Dump the fuel and fill the oil tank and watch for bar oil getting into the fuel tank.

 

[Willie2331]

Just an up date. Found putty gone from around metal plate in the picture. Disassembled and resealed everything. Fired up saw and adjusted carburetor. Smoke problem solved. Thanks for the information as I would have thought of this solution.

 

[Willie2331]

As a side issue. I am looking for a 507026383 umbrella valve for the fuel cap Poulan Pro 405. Mine is shot and squirts fuel out the vent. Would be interested in a complete fuel cap if available.

 

[fossil]

As a side issue. I am looking for a 507026383 umbrella valve for the fuel cap Poulan Pro 405. Mine is shot and squirts fuel out the vent. Would be interested in a complete fuel cap if available.

Holley Carb Carburetor Accelerator Pump Check Valves Umbrella 20 Pack A51
Here are the umbrella valve that are used on the fuel cap pioneer P40 and up check
e bay
I believe this Stihl unit works as well
Stihl's orange umbrella valve that was used in the tank vent of many older saws ( 036, 064, 066, others ) is the same size (or very close) and is still readily available through a Stihl dealer. Part number 1110-353-1600.

 

[Mastermind]

Holley Carb Carburetor Accelerator Pump Check Valves Umbrella 20 Pack A51
Here are the umbrella valve that are used on the fuel cap pioneer P40 and up check
e bay
I believe this Stihl unit works as well
Stihl's orange umbrella valve that was used in the tank vent of many older saws ( 036, 064, 066, others ) is the same size (or very close) and is still readily available through a Stihl dealer. Part number 1110-353-1600.

Good stuff right there.

 

[Willie2331]

Thank you for the umbrella seal info. This group has been a very good resource.

 

[Jtbayless1]

I have a Poulan Pro 405 1990 vintage. Has a Walbro WJ20a carburetor and I put in a Walbro repair kit. Saw runs well and cuts really good, but the exhaust is a little smoky and I can’t get it to clear up. Is it normal for an older saw of this type ?

I've got same carb I swapped on a p42 saw won't pull fuel, is it a bad check valve? I put rebuild kit in it diaphrams, metering lever needle screen on pump side. Fires with a squirt of fuel but line isn't pulling fuel from tank? Any help would be great.

 

[Mastermind]

I've got same carb I swapped on a p42 saw won't pull fuel, is it a bad check valve? I put rebuild kit in it diaphrams, metering lever needle screen on pump side. Fires with a squirt of fuel but line isn't pulling fuel from tank? Any help would be great.

Are you sure the impulse passage lines up?