Pioneer chainsaws

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That's exactly how it works now and would be fine if the stem end of the valve faced the tank instead of the top of the cap. (See post 14084 again.) Don't know how many more ways I can say "it vents in the wrong direction". LOL



I'm pretty sure my fuel cap has all the parts except the retainer and chain. But if you happen to have a valve assembly like the one in my cap I'd be most interested in how yours goes together!
I took apart two fuel caps, and they were both the same. I will dig in the rafters to see if I got any spares. The one spare I found the orange part was no good.IMG_20190806_144228.jpg
 
'Preciate the effort. That's Lou's style of vent. Much simpler design and actually vents inward! And those umbrella valves are still readily available if that's what you mean by 'orange part'. Wonder if that valve housing is the same size as mine? Problem solved if I could find one o' those and it fits.

My cap is one of these and it looks like someone else has already gone the sealant route on it somewhere along the line.

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Thank you p61 western;
Just like mine with the exception that mine never had a retainer and has a gasket between the piece that holds the umbrella and the cap.
Your camera is better than mine, you're a better photographer or both.
Order of assembly:
1. Cap
2. foam (complete with a dimple)
3. gasket (it might still be in your cap)
4. plastic piece that holds the umbrella valve with the high side to the tank.
5. umbrella valve, in 4 with the stem down and the large part toward the tank.
6. metal retainer
I'd like to see something similar for the cap Pogo has, complete with assembly instructions. I'll wager he'd like to see one too.

The only problem I've had with my fuel cap was swelling after we moved to Washington State (my saw was in storage from 1986 through 1991) and I started using pump gas containing ethanol. Storing it with no fuel onboard and using 100LL solved that problem too.

My saw was purchased at a saw shop in Alamogordo, NM (can you say Holloman AFB?) late 1979 or early 1980. For 6 years except for cleaning after every use, it was maintained by that shop. They even sharpened the chain. She did most of her cutting in the National forest near Cloudcraft, NM (8,000+ feet of elevation). We eventually purchased 10 acres in Cox Canyon (Cloudcroft area), NM and she did a fair amount there too. Anyone looking for 10 acres of mountain top in NM?

@ Pogo;
That 16:1 made me drag out my manual, that's what it says too. I had a Lawnboy 2 cycle lawn mower that wanted 28:1. I ran 24:1 in both.
 
'Preciate the effort. That's Lou's style of vent. Much simpler design and actually vents inward! And those umbrella valves are still readily available if that's what you mean by 'orange part'. Wonder if that valve housing is the same size as mine? Problem solved if I could find one o' those and it fits.

My cap is one of these and it looks like someone else has already gone the sealant route on it somewhere along the line.

Heck no wonder why that's a style cap that fits the older saws like the 1110 and such.
 
Those old fuel caps sure are fun now that the ethanol is swelling them up and eating out the innards, Pioneer went through a good many different designs from 1957 to 1985 and they differentiated again between models and production runs.
I always have one or 2 in the freezer lol. Just can't win with the **** fuels.
 
California has some very strict laws. Have you tried or looked for a bulk plant anywhere near you? That might be worth a try.
I go to a small local airport (Auburn WA) and dodge the private airplanes, while on foot, carrying my 5-gallon can. I usually get 3 gallons at a time.
If my Governor has his way I may be in real trouble. A carbon tax on everything that is trucked, flown, or travels by train. He wants to be President; Trump will get my vote before he does (I lied! but I'd have trouble voting for the Gov)!
 
Yours would appear to have a standard pink umbrella valve situated in there somehow. (I included one in the pic purely for illustration purposes.) Mine is a plastic mechanical valve with an 'O' ring and a spring to seal it and can only fit in the cap one way..., which has it venting outward allowing air (and fuel) to also vent/leak out unless outside air pressure is significantly higher than tank pressure. It allows no air back in to account for fuel volume loss and the associated vacuum created like a normal tank vent does. Makes no sense whatsoever. And we're actually talking about tank pressure equalization here anyway, not actual venting, per se.


Hi Poge.

Trying to decipher how that valve might work without having it...FWIW.

BTW, the pen tube/duckbill fix is still going strong. I noticed that if a fellow could drive out the sintered plug in the oil cap, it sure looks like a stub of pen tube would fit in there with the duckbill setup.

On a side note, I had a spare cap with the umbrella valve. It was never sealing worth a darn. I pulled the assembly apart and noticed that paper gasket is really all that seals the assembly between the bore of the cap. Leaking through there like a sieve even though the umbrella worked. I cut a new gasket from cork and dropped it in there. Drove the retainer in enthusiastically to seat the assembly firmly. Works like a champ now. Those paper-type gaskets clearly lost their function.
 
Most places in my neighborhood sell non ethanol 91 octane at around $3.35 a gallon as well as offroad diesel. I buy the non ethanol, well worth the cost. I felt like I was changing out the manifolds on everything once a year when I ran the new stuff and thats even with me running it dry every time. Thanks for all the details on the caps guys. I didn't contribute but I definitely benefited.:cheers:
 
Nothing like Canadian prices at the pump. 4 L of 94 ethanol-free runs about $6.60 on a good day. The lower mainland (Vancouver) runs higher.

That works out to $6.25 for the US sized jugs. No complaints from me though. Big place up here and not so many folks to fund it all.
 
Nothing like Canadian prices at the pump. 4 L of 94 ethanol-free runs about $6.60 on a good day. The lower mainland (Vancouver) runs higher.

That works out to $6.25 for the US sized jugs. No complaints from me though. Big place up here and not so many folks to fund it all.
I was going to say something similar, in Vancouver I can get 94, e-free, at some stations (Chevron), but it costs $1.66CAD/L or ~$4.75USD/gal. And that's a good price, earlier in the spring it was closer to $2/L.

Most of my chainsawing these days is milling, so it pays to use good fresh gas and mix. 090 top ends are expensive.
 
93 octane e-free generally runs a dollar a gallon more than 87 octane ethanol at a station near me. Puts it at around $3.65/gal. currently. Seasonal availability as marine fuel from April till November and replaced by K-1 for heating fuel during the winter. Available year round at another location 20 miles away if I run dry over the winter. Same deal at a buck/gal. more than 87 octane ethanol. I feel fortunate to have it available at all, let alone so reasonably priced.
 
I'm restoring a P40 for a family member and it has no spark. I've replaced the plug, filed the points and even removed the wire trimmed a little to give it fresh wire at the contact but while I had it apart I noticed the coil is separating from the plastic. I found this old thread which states the Homelite SXL coil will work. My question is will the solid state coil work eliminating the points all togethear and will the existing flywheel work? In the meantime I have the old one baking.
https://www.arboristsite.com/community/threads/pioneer-farmsaw-ignition-coil-swap.185371/

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