Pioneer chainsaws

[jsm0960]

Thanks for the help Brad. The tank actually had pressure in it. I ran the saw a few minutes when it started acting up. I have not had the saw too long, and have not ran it much, so I figured I would rebuild the carb sense I don't know the history of it. When I disconnected the fuel line from the carb, it shot a stream of fuel about 20" and kept it up until I kinked the line and opened the cap. I then reconnected the line and ran the saw five minutes, and it did the same thing. I can blow through the cap, it will let air in the tank, but not out. Any other suggestions would be appreciated.

You definetly have a vapor lock issue. You need to get it so the tank vents out. I have dealt with this problem several times. Run a drill bit down through the cap and recheck it. As soon as you get the tank to vent the saw will run at WOT again.

 

[jsmith40004]

P50

Trying to fix an old P50 that was my dad's. The ignition is the three piece design and was trying to locate something that would work. Thanks.

 

[pioneerguy600]

Yes, I have another ign. I could try. What do make of the tank pressure. Its a lot of pressure, not just a little.

Most of the old magnesium bodied saws with integral gas tanks will heat the fuel and cause it to expand. This is normal, do not run a drill bit through your cover, you will be looking for a replacement if you do. The cover vent is meant to let air in to the tank,not out or let fuel pressure out of the tank. When the P&C`s start to get some wear or scratches / galling then more heat is generated and some of that heat gets passed on to the fuel tank. I have foun that the high test gasoline has an additive that prevents boiling/excessive fuel expansion in the older saws. It takes close to 10 lbs of pressure to cause the carb to pop off if the spring under the metering lever is in good condition so usually a little pressure in the tank does not affect the engine much, it actually acts like a good fuel pump.
Pioneerguy600

 

[Busmech]

Don't drill your cap, it is only a one way valve, lets air in not out. If you drill it you'll have fuel spraying all over when you turn the saw on it's side. been there done that. I don' see how fuel could boil in a few seconds but i know if you shake a pioneer p series saw and pull the fuel line it'll spit quite a while.

 

[Arrowhead]

Thanks for the help guys. Yes, the cap works properly, it lets air in but not out. The fuel is not boiling, you can start it cold and in a few minutes of running, the pressure builds. Must be normal, I checked my other P's and they did the same, just not as bad. I had only about an 1/8 tank on the 51, so there was a lot of air space to compress. Just took me by surprise when it shot fuel like a garden hose when I removed the line off the carb. Thanks Again

 

[Arrowhead]

Trying to fix an old P50 that was my dad's. The ignition is the three piece design and was trying to locate something that would work. Thanks.

Welcome to the site. Do you know which piece you need? I may have it.

 

[jsmith40004]

The pickup on the outside and a flywheel as this one has about four fins missing

 

[WesternSaw]

Bar Length

When measuring bar length do you measure from the front tip of the bar to the end of the bar at the sprocket end?Or do you measure from the front tip to the front end of the bar stud slot
Many Thanks
Lawrence

 

[propliner]

When measuring bar length do you measure from the front tip of the bar to the end of the bar at the sprocket end?Or do you measure from the front tip to the front end of the bar stud slot?

The second option, from the bar tip to the front of the bar stud slot.

 

[Arrowhead]

The pickup on the outside and a flywheel as this one has about four fins missing

The only extra flywheel I have also has a few broke fins, I will check on the pick-up to see if I have a good one. There is a P60 flywheel on e-bay now. This will work on your saw, its the same as your P50. JacobJ mentioned on one of his last few posts that he had nos ignitions for them. You may want to send him a PM.

 

[WesternSaw]

The second option, from the bar tip to the front of the bar stud slot.

Thanks Brendon!
Lawrence

 

[DroppedP51]

Got my P61 running today The rings were stuck/jammed? into the piston,so i removed the jug got the rings off and cleaned it all up,Gave it a light hone and reassembled it,started and runs ok and is getting better and better with use ive put a 24" bar on it Ran 2 tanks of fuel through it and it just roars Im impressed with its power and its sound Will try and get a video of it in action

 

[Arrowhead]

Got my P61 running today The rings were stuck/jammed? into the piston,so i removed the jug got the rings off and cleaned it all up,Gave it a light hone and reassembled it,started and runs ok and is getting better and better with use ive put a 24" bar on it Ran 2 tanks of fuel through it and it just roars Im impressed with its power and its sound Will try and get a video of it in action

Congrats on getting it going.

 

[propliner]

Good work, Ed. Was there much carbon buildup or was something else causing the rings to stick?

 

[DroppedP51]

yes there was a lot of carbon buildup, The rings were sort of pinched in the grooves I cleaned up the piston with some 350 grit emery and feeler gauges, I am led to beleive the saw had been seized at some stage,The cooling fins were caked solid with sawdust 'Overheating? But the rest of the saw was in good cond.So all ive really done was dissasemble and cleand it up .What would cause the carbon build up? The exhaust port was 1/4" thick with carbon as well as top of piston and cylinder? Perhaps it was burning motor oil?

 

[propliner]

Yes, wrong type of oil maybe and definitely too much of it. Too much oil is worse than too little in my opinion. Carbon scratches everything in there and causes other problems like stuck rings.

I like to run 40:1 with Stihl two-stroke oil. It stays nice and clean. I used to burn Avgas which was great, but I recently ran out.

Caked up fins on a hot day is a recipe for disaster. I clean them out religiously. My big Varsol bath sure makes it easy, I just set the whole saw in there and scrub away with a long-bristled brush.

 

[DroppedP51]

yes i run stihl oil aswell but with 91 octane fuel , our 96 octain fuel is crap here since they took the lead away, Avgas is 100 and still leaded I should try some

 

[Arrowhead]

Good work, Ed. Was there much carbon buildup or was something else causing the rings to stick?

Brendon, I think you have use confused, David is DroppedP51.

 

[WesternSaw]

Got my P61 running today The rings were stuck/jammed? into the piston,so i removed the jug got the rings off and cleaned it all up,Gave it a light hone and reassembled it,started and runs ok and is getting better and better with use ive put a 24" bar on it Ran 2 tanks of fuel through it and it just roars Im impressed with its power and its sound Will try and get a video of it in action

Way to Go Dropped P51!
Lawrence

 

[propliner]

Brendon, I think you have use confused, David is DroppedP51.

Oops, sorry about the name mixup, guys.