Pioneer chainsaws

[fossil]

Since you ruled out the carb and the saw, all I can think of is a leak between the reed block and the carb or your decomp valve is opening or leaking while running. You might try plugging the decomp hole with a bolt to see if that's the issue.

 

[paul hill]

Since you ruled out the carb and the saw, all I can think of is a leak between the reed block and the carb or your decomp valve is opening or leaking while running. You might try plugging the decomp hole with a bolt to see if that's the issue.

I'm hoping I ruled the carb out but not positive. It seems to run well except for the erratic idle. But, I rebuilt and adjusted both carbs and I'm no expert at either. Both carbs are the same though.

I've checked the decomp while its running and replaced a new one with another new one. To be sure, I'll plug it just in case.

The carb to reed block gasket is new and I've swapped out a couple of them to hopefully rule that out but I guess it could be. I'll play with that some and see if I can figure anything out there.

Thank you for your ideas.

 

[PogoInTheWoods]

Any chance there is something weird going on with the choke or maybe the air filter that's prohibiting a proper/constant tune?

Just thinkin' out loud....

 

[Busmech]

Any chance there is something weird going on with the choke or maybe the air filter that's prohibiting a proper/constant tune?

Just thinkin' out loud....

Have you checked the reed block for cracks those are famous for hairline cracks?

 

[fossil]

Did the SDC from your 60 run well on the 60? Not to sound like an ass but, is the metering diaphragm hooked into the metering lever?

 

[fossil]

Any chance there is something weird going on with the choke or maybe the air filter that's prohibiting a proper/constant tune?

Just thinkin' out loud....

Poge,

I think there is always something weird going on with one of our saws at just about any time. I have two 900 series red saws that acted like they were leaking even though they tested fine. It eventually turned out to be bad carbs which had been gone through many times.

 

[paul hill]

The choke seems to work just fine on both carbs that I've tried. It closes all the way and there is no slop in the rod or lever. The air filter is new and looks good.

The reed block is new. I've been blocking off the outside of the reed block when I pressure/vac test and it shows no leaks. I have looked inside and the reeds look good. They are new as well. I have not removed the reed block though because I have it sealed up so well, I hate to have to do it again! But, I might have to.

Thanks very much for the ideas guys. This is a great saw and its driving me nuts that I can't get it running correctly.

 

[Acornhill]

Two different carbs same result leads to something deeper is the issue,

 

[paul hill]

Did the SDC from your 60 run well on the 60? Not to sound like an ass but, is the metering diaphragm hooked into the metering lever?

Yeah, the 60 runs well but I'm fighting a reed block leak on that saw so its not perfect. But it'll run well and doesn't have the idle issues or lean at the end of a cut. Yes on the metering diaphragm. I've done that one before! I now know to double check it now.

I've got a couple other SDC's that I got in a box of parts I bought. Don't know if they're good or not but I guess I could clean them up and try just in case.

I'm off to check some of these ideas and see what I can figure out. Thank you all for the input.

 

[DSS]

It sounds like you've got all the bases covered, but they are notorious for leaking at the reed to case gasket.

 

[DSS]

That 431325 (Pioneer #)or 507431325 (Poulan Pro#) will fit all of the P-series saws from P38 thru P65 except P-40

And it should fit the late P-40 as well. The first ones had a Bendix type recoil like a Farm saw, but they changed over to the pawl type starter part way through production.

 

[hillwilliam]

NEEDING SOME ADVICE

I'm hoping to get a little help/advice from some of the Pioneer experts here.

The saw is a P51 that has mostly been rebuilt recently. Put a ported cylinder on it with new rings. Went through the entire saw at the time except I did not mess with bearings, seals, or case splitting.

Rebuilt the carb (SDC 53) and it ran very well for a while. Then it started to idle erratically. I would set it at about 2700 rpm. After revving it up a little, the idle would sit at 3000-3200 for 15-30 seconds, then it would drop back down to 2500-2700. The saw ran great in the cut but went lean after the cut a couple of times. Most of the time after a cut, the idle will be very high for a while and sometimes the chain would continue to spin.

I have vac/pressure tested the saw at least 6 times. No air leaks at all. I rotated the crank quite a bit and it held pressure/vac. Did the same to the carb, it'll hold 7-10 PSI for 10 min +.

I've rebuilt the carb with a couple of new kits. I bought a US cleaner and ran the carb through that as well. Removed the welsh plugs too. Metering lever is even with the little raised bosses on the carb as per Walbro instructions but the saw will flood easily.

I've replaced the fuel lines, coil, plug, and nothing helped. I've pressure tested the fuel lines (new) and the tank vent on a brand new fuel cap.

Finally I swapped out the carb with the rebuilt SDC 53 off my 60. Got the same results.

I'm starting with 1 1/4 out on both carb screws but no amount of turning makes much difference.

I knew some of the big boys would chime in with some good advice. It just keeps coming back to the same possibilities you and I have talked about over the last month or so. I know you're going to do crank seals next, and I hope that solves it. That or a new carb. You've done about everything else.

What am I missing? Air leak when hot only? Lousy carb tuning (I'm no expert)? Not sure what else to try.

Thanks for reading all this and any help would be greatly appreciated.

 

[hillwilliam]

Dogs and velocity stacks

Does anyone have a pair of dogs like these on my good ol' P51 that they could part with? I don't really need to have the giant fangs on my 655, and I figure I could get by with a 30" bar if I used the shorter dogs like these.

Also, this is a little premature, but I think I'm getting closer to having some more velocity stacks made for P-series Pioneers (and whatever else they might fit). I don't know yet what they will cost me but, based on such scanty information, is anyone interested?

I've used v-stacks and K&N for 30 yrs. and like them a lot. I sure beats the stock Pioneer filters.

Thanks,
Jack

 

[hillwilliam]

NEEDING SOME ADVICE

I'm hoping to get a little help/advice from some of the Pioneer experts here.

The saw is a P51 that has mostly been rebuilt recently. Put a ported cylinder on it with new rings. Went through the entire saw at the time except I did not mess with bearings, seals, or case splitting.

Rebuilt the carb (SDC 53) and it ran very well for a while. Then it started to idle erratically. I would set it at about 2700 rpm. After revving it up a little, the idle would sit at 3000-3200 for 15-30 seconds, then it would drop back down to 2500-2700. The saw ran great in the cut but went lean after the cut a couple of times. Most of the time after a cut, the idle will be very high for a while and sometimes the chain would continue to spin.

I have vac/pressure tested the saw at least 6 times. No air leaks at all. I rotated the crank quite a bit and it held pressure/vac. Did the same to the carb, it'll hold 7-10 PSI for 10 min +.

I've rebuilt the carb with a couple of new kits. I bought a US cleaner and ran the carb through that as well. Removed the welsh plugs too. Metering lever is even with the little raised bosses on the carb as per Walbro instructions but the saw will flood easily.

I've replaced the fuel lines, coil, plug, and nothing helped. I've pressure tested the fuel lines (new) and the tank vent on a brand new fuel cap.

Finally I swapped out the carb with the rebuilt SDC 53 off my 60. Got the same results.

I'm starting with 1 1/4 out on both carb screws but no amount of turning makes much difference.

What am I missing? Air leak when hot only? Lousy carb tuning (I'm no expert)? Not sure what else to try.

Thanks for reading all this and any help would be greatly appreciated.

I don't know what happened a few minutes ago when I tried to reply . . .

I knew some of the big boys would chime in with some good advice. I keeps coming back to the same things you and I have talked about for the last month or so.
Next will probably be new crank seals. I hope that or a new carb takes care of it. You've already done about everything else.

 

[kz1000]

I've got a dealer that had some Pioneer and Partner bars, picked up a few and thought that I would check on interest. The Pioneers are 28" hard nose and the Partners are 22" rollers. If I see an interest I'll list a few on trading post to be safe.

 

[pioneerguy600]

Very nice bars, they last really well also, made back when good steel was relatively cheap.

 

[paul hill]

I've got a dealer that had some Pioneer and Partner bars, picked up a few and thought that I would check on interest. The Pioneers are 28" hard nose and the Partners are 22" rollers. If I see an interest I'll list a few on trading post to be safe.

I may be interested in one or more of the 28" bars. What pitch and guage are they?

Any idea on what the cost might be?

Thanks for sharing, nice find.

 

[kz1000]

The 28" are 3/8 .058 and I think that is what the Partners are.

 

[Lou]

Does pitch matter on a solid nose? With no sprocket I don't think so. Am I correct the chain is run slightly looser?
Lou

 

[kz1000]

Good point, I guess gauge but not pitch.