Poulan S25 fuel line replacement

[Modifiedmark]

Here is another how to on the fuel line for a Poulan 25, 25D S25DA or S25CVA, since this question comes up alot, and I mean a lot.

Most think that this is like figuring Chinese arithmetic but it's really pretty straight forward and actually pretty easy for a top handle saw.

Here is my S25DA that needs the line replaced due to Ethanol damage to it.

First thing to do is to remove the air filter/carb cover and the recoil housing.

Here you can see where the line runs through the loop in the case to guide it around behind the flywheel to secure it from contacting the flywheel.

To make it easier I remove the flywheel to allow access to run the fuel line.

The way the combustion chamber is shaped its hard to use a regular piston stop on these, plus the way the plug is recessed there hard to get in as well.

I use some nylon starter rope to stop the piston from turning over. Get the piston close to TDC then just stuff some rope in the plug hole to stop the piston from turning.

Once the rope is in you can remove the flywheel nut with a 1/2" socket. Make note of the direction that the washer under the nut is positioned as it is a beveled washer and the center has to point up when reinstalled.

To remove the flywheel I use the method listed in the Poulan service manual. Grasp the flywheel with one hand from the face of it and lift the saw up. Then take a small hammer and tap the side of the flywheel opposite the magnets. Be carefull to hit flat and don't hit any fins on the flywheel.

They useally come right off with a couple taps.

Here is the flywheel removed where you can see how the line has to be run behind it.

 

[Modifiedmark]

You can now remove the fuel line from the carb inlet fitting, pull the old line out from underneath, then remove the filter from the line in the tank and pull the line from the hole in the tank.

You then want to take a piece of 1/8"ID X 3/16" OD fuel line about 15" long and cut a angle on each end.

I start by threading the line through the loop in the case and pulling it though with a pair of hemostats. Pull approximately enough to reach the carb. Don't worry if it's not exact, you can adjust later.

You then can thread a piece of stove pipe wire down through the hole in the carb box down and hook it through the angle cut in the new fuel line.

Now you can pull the wire and fuel line up through the hole into the carb box area.

Cut the angled end of the fuel line flush and install the line on the fuel inlet on the carb. You can pull the line up or down to get the right length at this time.

 

[Modifiedmark]

While your in the carb box make sure that the foam seal around the throttle linkage is still there and in good condition. Lots of folks don't realize this is needed here as a lot of these old saws have there's missing from age and deteriation. If this seal is not in place it will allow dirt and such to bypass the air filter and allow debris into the engine.

Here is a picture of the seal.

Now you want to fish the other end of the line in through the hole in the tank. I run a wire through the hole and out the filler hole then tie the wire into the line through the angled end.

Pull the line up through the fille hole and cut the line flush at approx 2 1/8" above the top of the tank.

Install the fuel filter on the line, drop it back in the tank and reassemble in the reverse order that you took it apart.

Make sure you get the flywheel lined up on the crankshaft keyway and get the flywhell nut tight.

 

[stubnail67]

very nice!!!!

even better write up!!!!! Itried to rep ya but it would not let me!!!! said i had to spread the love around first...... think ya could add the duckbill in the cap to it i keep bending the lil mteal sproket thing all to heck when i pry it out????cant beleive no one has saw this one!!!!

 

[HittinSteel]

Very nice write up Mark. Certainly will be nice to have in the archives when the question comes up.

 

[tmessenger]

Thanks Mark I've been thinking about building one of these up for myself so this kind of tutorial is very valuable to all of us wrenchers.

tm

 

[Ganz]

Awesome job Mark, rep sent

 

[Sprintcar]

Super Job!

Once again an excellent tutorial by one of the most knowledgeable and senior members of AS. I would Rep you if I could, keeps telling me I've got to spread it around.

The pictures are great Mark, especially for dummies like me.

 

[Modifiedmark]

Very nice write up Mark. Certainly will be nice to have in the archives when the question comes up.

That was my motivation! Thanks fellas!

 

[OhioGregg]

Mark, Thanks for that tip on the foam gasket around the throttle linkage. I'm not sure if mine have it or not now. Will have to check that out. Learn something new or usefull most everyday here.

Gregg,

 

[joe25DA]

Great write up Mark
Is that the 25 I sent you? I cant remember if it had a vinyl coated handle or not. Either way that saw is in nice shape.

 

[ring bing bing]

Great walk-through! Did mine last night and it only took about 15 minutes thanks to your help. Previous owner shelved the saw because he thought the job just looked too difficult. Thanks again.

 

[Modifiedmark]

Great walk-through! Did mine last night and it only took about 15 minutes thanks to your help. Previous owner shelved the saw because he thought the job just looked too difficult. Thanks again.

Thanks for the post.

Glad to see that somebody new used the search, found this and it helped them. That was the reason for me doing it, and makes it worth the time it took to do it.

Oh and welcome to the site!

 

[Eccentric]

Bumpin' a great old thread to the top!

 

[cfischer]

Remove Flywheel from Poulan S25

Modifiedmark,

I am reading your instructions on replacing the fuel line for this chainsaw. Your instructions and the photos are excellent. Thank You. However, is there a "Plan B" for removing the flywheel. I am working on a Craftsman Model #358-350871, which is (so far) identical to the photos you posted. The problem right now is that the flywheel does not come off when I suspend the chainsaw by holding the flywheel and tap it with a hammer. Was there a modification for the Craftsman that requires a different procedure to remove the flywheel? I'm baffled. Any suggestions?

Thanks for your help

 

[cfischer]

While your in the carb box make sure that the foam seal around the throttle linkage is still there and in good condition. Lots of folks don't realize this is needed here as a lot of these old saws have there's missing from age and deteriation. If this seal is not in place it will allow dirt and such to bypass the air filter and allow debris into the engine.

Here is a picture of the seal.


Mark,

I forgot to mention in my last post that I don't see the foam seal in my saw. Can I fashion a new one with air filter foam?

Thanks again

 

[cfischer]

Remove Flywheel from Poulan S25

Never mind on removing the flywheel. On about the twentieth try it fell off just like you described.

Thanks again for your post.

 

[a. palmer jr.]

Nice job on the write-up, Mark. Usually, by the time I get these saws the fuel line has already been replaced once and they generally don't put the line through the hole where you did. A couple of mine had the line routed behind the coil and one just had it hanging there with the flywheel rubbing it in two.

 

[7hpjim]

Great thread, I have a CV model that needs a line, and also does anybody know where to get the duckbill valve for the fuel cap as both of my top handle poulans need replaced.

 

[nelson727]

mowers4u.com - Duck Bill Valve #530026119

Great thread, I have a CV model that needs a line, and also does anybody know where to get the duckbill valve for the fuel cap as both of my top handle poulans need replaced.

mowers4u.com Duck Bill Valve # 530026119. $1.50 or so for the part $3 or so for shipping. If ever will use more It's cheaper to get a few extra.