Pioneer P25 fuel line/filter

[aljewett]

Good day all. I picked up a honey of a P25, barely used, but the carb needed a rebuild. Job completed, saw runs great. So then, I thought I would take a quick peek in the fuel tank. The filter looked like it has been breathing sawdust for the last 45 years. While trying to hook it, the line broke. No big deal I thought, it has to be replaced anyway. But the routing is interesting. The filter line connects to a male connector inside the tank, then the carb line attaches to the male connect opposite the other one. At first glance, it appears that I might have to break the tank open in order to attach a new line, but I don't want to do that. Too many related problems (broken gasket, throttle spring doing a disappearing act, removing the flywheel, etc.)
Has anyone tried replacing a fuel line on a P25 and been successful? I'd really like to get it back to near new, and that shouldn't be too difficult.
Thanks,
AJ
P.S. Just to confirm, RH thread on the flywheel? LH on the clutch?

 

[aljewett]

Good day all. I picked up a honey of a P25, barely used, but the carb needed a rebuild. Job completed, saw runs great. So then, I thought I would take a quick peek in the fuel tank. The filter looked like it has been breathing sawdust for the last 45 years. While trying to hook it, the line broke. No big deal I thought, it has to be replaced anyway. But the routing is interesting. The filter line connects to a male connector inside the tank, then the carb line attaches to the male connect opposite the other one. At first glance, it appears that I might have to break the tank open in order to attach a new line, but I don't want to do that. Too many related problems (broken gasket, throttle spring doing a disappearing act, removing the flywheel, etc.)
Has anyone tried replacing a fuel line on a P25 and been successful? I'd really like to get it back to near new, and that shouldn't be too difficult.
Thanks,
AJ
P.S. Just to confirm, RH thread on the flywheel? LH on the clutch?

Looking at the male connector in the air box, it looks like it might unscrew from the housing, but it also looks like it's glued on there pretty good. Just sayin.

 

[Joab]

The flywheel nut and sprocket are both left hand threaded -- a small P-series oddity. (The large P-series used a splined clutch drive and both sides were right hand threaded -- another oddity.)

I've done the fuel line repair before and I don´t recall that I had to crack the case -- I´ll take a look at my p-25 parts saw and try to remember how I did it.

 

[Joab]

The flywheel nut and sprocket are both left hand threaded -- a small P-series oddity. (The large P-series used a splined clutch drive and both sides were right hand threaded -- another oddity.)

I've done the fuel line repair before and I don´t recall that I had to crack the case -- I´ll take a look at my p-25 parts saw and try to remember how I did it.

Take the filter and any clips off the end of the fuel line, unscrew the tank feed, and pull the tank line through. Replace the fuel line (tygon works well) and feed it back through.

 

[Joab]

I guess my parts saw is a P-26 and not a P-25; but I'm pretty certain it's the same. Some light heat might help get the fitting out if it's gummed up with some kinda sealant.

If the fuel line is shot there's a good chance the fuel vent valve is too and, if so, it'll leak fuel out through the vent hose if tipped the right way. There's a duck bill valve behind the freeze plug that you can replace and I've done that before too -- I'd strongly recommend not doing it that way. (I couldn´t find the original part and I found it hard to track down a freeze plug that fits -- and hard to get the old one out without damaging anthing.) It's much easier to put an aftermarket echo-type fuel vent one-way valve on the end of the hose inside the airbox. There was a discussion on this a while ago: https://www.arboristsite.com/threads/pioneer-chainsaws.70698/post-6501058

 

[aljewett]

The flywheel nut and sprocket are both left hand threaded -- a small P-series oddity. (The large P-series used a splined clutch drive and both sides were right hand threaded -- another oddity.)

I've done the fuel line repair before and I don´t recall that I had to crack the case -- I´ll take a look at my p-25 parts saw and try to remember how I did it.

The more I look at the fitting in the airbox, the more I think it comes off to accommodate work on the fuel line.

 

[aljewett]

The flywheel nut and sprocket are both left hand threaded -- a small P-series oddity. (The large P-series used a splined clutch drive and both sides were right hand threaded -- another oddity.)

I've done the fuel line repair before and I don´t recall that I had to crack the case -- I´ll take a look at my p-25 parts saw and try to remember how I did it.

How do I know, small p or big P?

 

[aljewett]

Take the filter and any clips off the end of the fuel line, unscrew the tank feed, and pull the tank line through. Replace the fuel line (tygon works well) and feed it back through.

View attachment 952722

Ahhh. That's what I figured. My tank feed fitting is knurled....shouldn't be a problem. Much thanks!

 

[Joab]

How do I know, small p or big P?

If the fuel and oil caps are on the side, it's the small series and if they're on the top it's the large. There are, of course a lot of other differences but that's a really obvious one. The small P series are the saws in the 50cc range based and mostly all used P2x model numbers -- P25, P26, P28, etc. The large P series were in 65cc+ range and had model numbers P4x, P5x, and P6x -- P40, P41, P50, P52, P60, etc.

 

[litefoot]

Good day all. I picked up a honey of a P25, barely used, but the carb needed a rebuild. Job completed, saw runs great. So then, I thought I would take a quick peek in the fuel tank. The filter looked like it has been breathing sawdust for the last 45 years. While trying to hook it, the line broke. No big deal I thought, it has to be replaced anyway. But the routing is interesting. The filter line connects to a male connector inside the tank, then the carb line attaches to the male connect opposite the other one. At first glance, it appears that I might have to break the tank open in order to attach a new line, but I don't want to do that. Too many related problems (broken gasket, throttle spring doing a disappearing act, removing the flywheel, etc.)
Has anyone tried replacing a fuel line on a P25 and been successful? I'd really like to get it back to near new, and that shouldn't be too difficult.
Thanks,
AJ
P.S. Just to confirm, RH thread on the flywheel? LH on the clutch?

I don’t have an answer, but I wanted to congratulate you on your find. Years ago, when I was actively collecting/restoring saws, I acquired a lot of Pioneer saws and they became my favorite “old” saws. Love the design, color , the logo, the sound, and the torque of the P saws.

 

[aljewett]

Latest update;
Joab was bang on, thanks. I’ve posted a before and after shot. Now I just need a fuel filter and she’s good to go!