Pioneer chainsaws

[Arrowhead]

Ed, the boost port topic was covered earlier in the thread. I posted pics which explain everything.

Brendon, I searched the thread and can't find any pics of the boost port. Do you know what page? Thanks

 

[propliner]

I got tired of looking for them as well so I'll just repost them. You can see the cutaway in the piston where the mixture would rush up from the crankcase, around the thin part of the piston and along the boost port.

 

[briantutt]

Finally

I finally got my clutch removal tool made for my P25. It's a 1-5/16 socket with two 7mm pieces of drill rod brazed in the corners. One smack with the impact wrench off she came.

Now I can pull this thing all the way apart and reverse course.

 

[pioneerguy600]

I finally got my clutch removal tool made for my P25. It's a 1-5/16 socket with two 7mm pieces of drill rod brazed in the corners. One smack with the impact wrench off she came.

Now I can pull this thing all the way apart and reverse course.

Way to go, I like making all sorts of speciality tools for working my old/vintage saws over. Have a variety of old sockets with bits welded on for clutch removals.
Pioneerguy600

 

[Arrowhead]

Thin or thick rings

I need your opinions. I ordered a nos P60 piston for my rebuild project from Rottmans. I gave them the part # from the ipl. They said the number had changed to 476208j. I noticed this is the same # as the p62 piston on the ipl. I received the piston today, and I noticed it had the thick rings, unlike my other 98cc saws. It also has a cut-out on the side like the pic. Brendon posted for the boost port. I called them today to question them about it. I mentioned it looked like a 655bp piston. They said they would check into it and call me back. A few hours later they called me back and said that it was an upgraded piston that Pioneer had replaced the old style with, and that the 655bp was a different part #. They said it would work fine in the P60. Now this is my question, I have heard a few times the thin ring saws performed better than the thick. Is this true? Do you think I would be better off with this piston or a thin ring? I have a thin ring piston that's in good shape and have a set of nos rings for it. I figured sense I'm doing a 100% restore and plan on using this saw as my #1 work saw to put a brand new piston in it. Am I over thinking this? I also plan on porting this saw and want to get everything out of it I can. For the best results should I use this set-up or the thin ring, or does it really matter?

 

[briantutt]

Thanks

Brazing job isn't that pretty but it seemed to work. Maybe the next one will be better!

 

[pioneerguy600]

Thanks

Brazing job isn't that pretty but it seemed to work. Maybe the next one will be better!

Practice makes perfect, or at least it improves the more we do.
Pioneerguy600

 

[pioneerguy600]

I need your opinions. I ordered a nos P60 piston for my rebuild project from Rottmans. I gave them the part # from the ipl. They said the number had changed to 476208j. I noticed this is the same # as the p62 piston on the ipl. I received the piston today, and I noticed it had the thick rings, unlike my other 98cc saws. It also has a cut-out on the side like the pic. Brendon posted for the boost port. I called them today to question them about it. I mentioned it looked like a 655bp piston. They said they would check into it and call me back. A few hours later they called me back and said that it was an upgraded piston that Pioneer had replaced the old style with, and that the 655bp was a different part #. They said it would work fine in the P60. Now this is my question, I have heard a few times the thin ring saws performed better than the thick. Is this true? Do you think I would be better off with this piston or a thin ring? I have a thin ring piston that's in good shape and have a set of nos rings for it. I figured sense I'm doing a 100% restore and plan on using this saw as my #1 work saw to put a brand new piston in it. Am I over thinking this? I also plan on porting this saw and want to get everything out of it I can. For the best results should I use this set-up or the thin ring, or does it really matter?

My understanding of pistons with 2 rings is that they are better for a work saw, they last longerm make better sealing of the cylinder over a longer time period and transfer heat from the piston to the cylinder better. The cylinder is what dissapates the heat from the combustion and friction in a two stroke engine. The one ring piston was used in saws that revved a little faster,they have less drag than two ring pistons but they wear faster and also do not transfer heat from the piston to the cylinder as well. I would prefer the two ring piston in any work saw that I was building and only consider one ring pistrons for high speed modified chainsaws that I don`t mind doing a re-ring job on more often. IMO
Pioneerguy600

 

[Jacob J.]

Didn't the 655 use a different size wrist pin than the P-60/61?

 

[Arrowhead]

My understanding of pistons with 2 rings is that they are better for a work saw, they last longerm make better sealing of the cylinder over a longer time period and transfer heat from the piston to the cylinder better. The cylinder is what dissapates the heat from the combustion and friction in a two stroke engine. The one ring piston was used in saws that revved a little faster,they have less drag than two ring pistons but they wear faster and also do not transfer heat from the piston to the cylinder as well. I would prefer the two ring piston in any work saw that I was building and only consider one ring pistrons for high speed modified chainsaws that I don`t mind doing a re-ring job on more often. IMO
Pioneerguy600

Thanks Jerry, The thin ring piston I have also has two rings. The rings are approx. 50% thinner as this one.

 

[propliner]

Didn't the 655 use a different size wrist pin than the P-60/61?

I do believe that the 655 wrist pin is a different size than the P60/61/62 saws.

Ed, check that your wrist pin fits into this piston. If it doesn't and you're in a jam and want to do it right, I'll swap you that 655 piston for a P61 piston.

Brendon.

 

[Arrowhead]

I do believe that the 655 wrist pin is a different size than the P60/61/62 saws.

Ed, check that your wrist pin fits into this piston. If it doesn't and you're in a jam and want to do it right, I'll swap you that 655 piston for a P61 piston.

Brendon.

Is the P61 piston new and thin ring? The part # says its a P62, I will check the wrist pin though.

 

[propliner]

Is the P61 piston new and thin ring? The part # says its a P62, I will check the wrist pin though.

Yes, it's new and it's a thin-ringed piston. I just got it in but if you need it, it's yours. I have the boost port cylinder pictured above which will fit any big saw (it's missing the bottom shoulder) and I could always use another boost port piston to go with it.

 

[Arrowhead]

Yes, it's new and it's a thin-ringed piston. I just got it in but if you need it, it's yours. I have the boost port cylinder pictured above which will fit any big saw (it's missing the bottom shoulder) and I could always use another boost port piston to go with it.

I tried to fit the pin in the piston. It would not fit. I measured the pin at .5 inch and the piston at a 1/32" smaller at 15/32". Do these measurements sound right?

 

[propliner]

I tried to fit the pin in the piston. It would not fit. I measured the pin at .5 inch and the piston at a 1/32" smaller at 15/32". Do these measurements sound right?

I'm afraid so, Ed. If you have rings for this thin-ringed piston of mine, I'll ship it off to you. Then you'll know that it's being done with the proper original parts. Are you using a new cylinder?

 

[Arrowhead]

I'm afraid so, Ed. If you have rings for this thin-ringed piston of mine, I'll ship it off to you. Then you'll know that it's being done with the proper original parts. Are you using a new cylinder?

Yes, I have nos thin rings for the piston, no I don't have a new cylinder though.

 

[Jacob J.]

I tried to fit the pin in the piston. It would not fit. I measured the pin at .5 inch and the piston at a 1/32" smaller at 15/32". Do these measurements sound right?

Yeah you can't swap P-655 pistons with P-60/61 cranks. I tried finding a custom wrist pin bearing that would make up the difference too with no luck (and I have an assortment of over 85 different sizes of wrist pin bearings.)

 

[Arrowhead]

Yeah you can't swap P-655 pistons with P-60/61 cranks. I tried finding a custom wrist pin bearing that would make up the difference too with no luck (and I have an assortment of over 85 different sizes of wrist pin bearings.)

Whats crazy is I questioned Rottmans about it being a 655bp, and they said no, totally different part number. Thats after hours of them checking into it.

 

[Arrowhead]

Didn't the 655 use a different size wrist pin than the P-60/61?

Thanks for mentioning this, it is indeed different. I must spread the rep, or I would hit ya with some more. Thanks

 

[Arrowhead]

I'm afraid so, Ed. If you have rings for this thin-ringed piston of mine, I'll ship it off to you. Then you'll know that it's being done with the proper original parts. Are you using a new cylinder?

I will send the piston and rings in trade for the thin piston, sound good to you? I also have the rest of your parts, I will ship them also.