First Attempt Build Old poulan 4000

[Thesandman]

I've got a old 1984/5 saw that is pretty ruff that I would like to restore plus some. Problem is there is so much to these simple little saws, I'm scared of ruining it. Being a 4 stroke guy I thought I could find some easy fast improvements. Not so. Carb has two bars in throat forming a corner on half of Venturi area and semi circle on rest. This is unlike anything I've ever seen. Intake tract is a short tube that dumps into side of a area maybe twice the area or more of tube that bolts to intake port. Perhaps a pressure area(Helmholtz resonator). I don't know what I'm looking at. Do other saws have this? It appears poulan was going for disturbed airflow. Not sure where this post goes. Feel free to move to correct location. Yeah ha ha I'm definitely confused. Thanks

 

[Thesandman]

I got the modded cylinder on and did some cuts with it. It isn't cutting any faster rpm wise but it seems to have mo pwr. It was raining and got dark. I pulled a bonehead move. I did a test start and carb adjust. No bar, chain or side cover. I revved it up and saw bark and dirt fly. That was my clutch coming loose and flying apart. I now have half a clutch. I used one from #1 4000 to run test. I will put tach on tomorrow and check it out. Also I used original rings instead of new so I think there is more to be had there. There is more compression but not sure how much. I can easily take ten more off base.

 

[Thesandman]

Well it was a success. Compression 150psi hot. 9k plus rpm,s in the cut with 20" bar burried in dead ash. I have a .020bg on saw and have a .010 bg made so is it worth it to switch? My intake numbers would be a little better. I reached my goal with what I have right now. Now my new goal is 10k in cut. Is that obtainable? I'm right at 9200 now. Saw has power to set spikes and pull up staying at 9ish. Man saw has really come alive in just 1000rpm,s in cut. Not the best day to make hp either, 40* and very humid.

 

[Thesandman]

I think with new bg and bigger carb it might get there. It sure is well mannered, idling real nice at low rpm. Maybe put new rings in also. I'm looking forward to next winter now.

 

[David Young]

I recently worked on a 3700. I’d pull the gasket if you can and give it a bunch of ignition advance.

 

[David Young]

105 122 74.
Squish at .030 with a .010 gasket

.050 cut from the band.

 

[David Young]

More pics

 

[Wood Doctor]

Here's my 4000 and it runs very well:

I should have used it last Sunday and I promise to use it this spring. Surprising power, it is worth restoring if you can. It was built back when Poulan saws were well-made. It is anything but a Wild Thing toy. Thank heavens for that.

 

[Thesandman]

Thanks Brother David; I've been wanting to talk to someone that has experience on these. My intake looks just like yours. I've taken .040 off base. Cleaned up squish a little @.020 with .020 base gasket, cut .025 off key, settings are ex100 trans 124 int 67 going from memory that isn't good. I can pull bg and cut squish but I don't want a saw I can't start. I'm running rings that are 38yrs old. Man that 3700 runs great. The weather here is going to be better tomorrow and I can get saw in wood to see what's up. It's sweet running a American made saw that's almost all metal. It was heavy carrying it out to log but was lite on way back. I found out how to make a big heavy saw light. Add mo powr.

 

[Thesandman]

Well I just made some cuts with the 4000 2.0. First thing is starting saw it pulls very hard. Maybe too much timing. I don't think compression is that high. I will try pulling with kill switch activated. Saw cuts nice. It's not a rocket by any means but very nice. I think I'm going back to .025 on rakers to smooth things out. I'm going to stay with what I have for time being. Saw isn't as pleasant to start as it was stock but it's got some nadds now. I think 20"bar is plenty for saw. I need to cut some smaller stuff to get a better feel where saw is at.

 

[Thesandman]

Just checked compression is 160 cold and saw pulls thru with kill switch activated(off position). It pulls and locks at tdc with it in on position but doesn't kick back. But stops solid. I think timing is perfect at high speed but starts hard.

 

[Thesandman]

Just cut some small hard ash with both saws and pulan is a lot faster(3sec.) in 9 to 10 inch stuff. 5to6 vs 8to9. This is substantial since the 590 cuts very good. 1/3 faster

 

[Wood Doctor]

Just cut some small hard ash with both saws and pulan is a lot faster(3sec.) in 9 to 10 inch stuff. 5to6 vs 8to9. This is substantial since the 590 cuts very good. 1/3 faster

Gasp! I better not tell that to one of my tree service companies that I service and owns three 590's. You may have convinced me to take the bar off my saw in post #8, sand it down a tad, and then coat the bar with black enamel, just to spuce it up. I might get some raspberries here for doing it, but I have some time.

 

[Thesandman]

I'm amazed at how few parts it took to cut for twenty plus years, couple carb kits, new carb, couple plugs and filters. Original mix was 32 to 1(1/2pint to gal). I'm going to restore #1 this summer. Trying to get new sprocket nose for origional bar. Keep getting nla.

 

[Thesandman]

Well Dyno results show I'm close to 5hp without doing any port timing changes other than setting squish and polishing intake and ex. and muff mod. Power is very broad peaking at 8500rpm. I'm going to work on intake trac and timing along with intake side trans uppers. I might look into a echo cs620 carb as a possible swap.

 

[Dub11]

Well Dyno results show I'm close to 5hp without doing any port timing changes other than setting squish and polishing intake and ex. and muff mod. Power is very broad peaking at 8500rpm. I'm going to work on intake trac and timing along with intake side trans uppers. I might look into a echo cs620 carb as a possible swap.

You got a nice saw there sir. And thanks for sending it to Joe.

I have a ported Craftsman 3.3 with a carb off a 590. Very nice upgrade if I do say so myself. And @Termitebuffet did it for me.

 

[Gullet]

You got a nice saw there sir. And thanks for sending it to Joe.

I have a ported Craftsman 3.3 with a carb off a 590. Very nice upgrade if I do say so myself. And @Termitebuffet did it for me.

Dang I wish I hadn't read that.
I have 2-3.3's & they are my go to camp/firewood saws.
May have to try a 590 carb on one.
Direct bolt on?

 

[Woodslasher]

I'm amazed at how few parts it took to cut for twenty plus years, couple carb kits, new carb, couple plugs and filters. Original mix was 32 to 1(1/2pint to gal). I'm going to restore #1 this summer. Trying to get new sprocket nose for origional bar. Keep getting nla.

What bar is on it? If it's a Windsor finding a tip shouldn't really be an issue at all.

 

[Dub11]

Dang I wish I hadn't read that.
I have 2-3.3's & they are my go to camp/firewood saws.
May have to try a 590 carb on one.
Direct bolt on?

The choke need some work to work. I'll snap some pics of it here later.

 

[Thesandman]

I have a new Oregon on now. Old original is Windsor