Chraftsman/poulan gas tank vent issues

[Matt018888]

Hello to all... new here, first post, all though I have snooped here for a while now. I have a chraftsman 42cc 18 inch chainsaw, I know it's a throw away! I also own many stihl chainsaws aswell. Tore the saw apart put new fuel lines and a carb on it, I tuned it and it runs great for a while then fuel leans out and starves the carb I notice it will idle down and not bog WOT when I pull the fuel cap off. The cap is the duck bill style of venting. It appears to be in good shape. They seem to be problematic. So I was thinking, I have left over fuel vents from other stihl builds. Do you think its possible to drill a hole through the top of the gas tank and vent it like a stihl? Than just screw a machine screw into the cap vent to delete it? Has anyone tried this? Hoping to have this cheap saw as a lender when my brother in laws ask! Lol.

 

[ammoaddict]

I have one of those saws too and the duck bill leaks. That is a great idea you have. I hope someone will reply that knows if it will work. I will do mine if it does.

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[Clifford NC]

If you make your own vent, check out the poulan gas caps from China on ebay. A lot of them do not have a vent - solid caps.

 

[s sidewall]

If it's not venting, the brass sintered vent in the cap is clogged. Carefully remove the duck bill valve retainer and valve and flush out the vent. It's pressed into the cap and will become clogged over the years. It's a quick and easy fix that should last a couple of years like any other saw. If it's leaking fuel, install a new duck bill valve.

Steve Sidwell

 

[Matt018888]

If it's not venting, the brass sintered vent in the cap is clogged. Carefully remove the duck bill valve retainer and valve and flush out the vent. It's pressed into the cap and will become clogged over the years. It's a quick and easy fix that should last a couple of years like any other saw. If it's leaking fuel, install a new duck bill valve.

Steve Sidwell

I actually punched out the brass filter thing. Didn't help. If the fuel level is below the duck bill it will pull air through it and work fine. If the fuel level is above duck bill it wont pull air and the vacuum will starve the carb of fuel.

 

[Matt018888]

I have one of those saws too and the duck bill leaks. That is a great idea you have. I hope someone will reply that knows if it will work. I will do mine if it does.

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Well in the name of science I'll try it. I'll report back with pics and let you know how it works.

 

[s sidewall]

If the valve is good, something else is causing the problem. Valve should be able to open real easy and not stick together. Good luck.

Steve Sidwell

 

[Matt018888]

If the valve is good, something else is causing the problem. Valve should be able to open real easy and not stick together. Good luck.

Steve Sidwell

Well leak test check out good. Compression good. Maybe the new Chinese carb

If the valve is good, something else is causing the problem. Valve should be able to open real easy and not stick together. Good luck.

Steve Sidwell

Ok thanks. It seems to open fairly easy, but I have nothing to compare it to. I did throw a new piston and rings in, bearings and seals, as well as a Chinese carb. Maybe have 40.00 into. Saw passed the leak down test. I wonder if maybe the Chinese carb doesn't have the draw of the OEM? I'll try the auxiliary vent just to see if that fixes it. I didn't want to put a lot of money into to the saw, it was just appealing because it was free and had a new B & C.

 

[s sidewall]

New factory fuel caps are cheap. When mine got hard to removed, I ordered a new set off the Bay. Works good, kept the old set for a backup plus my other Poulans use a different style.
I was thinking carb issue if it won't open that valve. What was wrong with old carb?
Steve Sidwell

 

[Matt018888]

New factory fuel caps are cheap. When mine got hard to removed, I ordered a new set off the Bay. Works good, kept the old set for a backup plus my other Poulans use a different style.
I was thinking carb issue if it won't open that valve. What was wrong with old carb?
Steve Sidwell

Nothing but the carb rebuild kit was the same cost of the Chinese carb. Thought I save a step and just buy new.

 

[ammoaddict]

Nothing but the carb rebuild kit was the same cost of the Chinese carb. Thought I save a step and just buy new.

The Chinese carbs are hit and miss. I got one on my 365 and it is good. I've got one on my 660 kit and it is hard to start but runs great once you get it fired up.

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[Matt018888]

Aux vent did the trick so duckbill must have stuck.

 

[Matt018888]

Drilled a hole on the side closest to the vent on cap.

 

[Matt018888]

Sacrificed one vent to use the nipple, so that the line could not be pulled through the top of the gas tank.

 

[Matt018888]

 

[Matt018888]

Now there is a standard stihl vent. I screwed a machine screw into the cap vent hole to delete it. All works well, and no more dealing with leakey caps or clogged vents. Thanks to all for your responses hopefully this will be useful to someone as I have used lots of information from here, and just wish to contribute.

 

[ammoaddict]

Now there is a standard stihl vent. I screwed a machine screw into the cap vent hole to delete it. All works well, and no more dealing with leakey caps or clogged vents. Thanks to all for your responses hopefully this will be useful to someone as I have used lots of information from here, and just wish to contribute.
View attachment 806225

Awesome. Thanks for sharing. I thought I had an extra vent but I don't.

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[TRTermite]

I hammered/pounded/drove a small finish nail from outside inward. It pushes the sintered brass out and the swaged head does the one two seal. Then a snip with the dikes, I could have shortened it before putting it in..... I had a connecting nipple to stop the line from pulling out.
Anyone try the grub screw concept like the Stihl 025? Has to be pudhed not screwed in but takes up less space ..