Nik's Poulan Thread

[hotshot]

Hotshot, I used the skf seals (getting ready to order 2 more to either replace the ones in the craftsman or as spares for my Poulan.

As for leak testing, honestly I dont think it improved any but my blockoff gaskets could be leaking. Saw would drop fro 7psi to 5 psi in 30-40 seconds. In vacuum test results were slightly better, took roughly 40sec to go from 7 to 5 inches of mercury. Dont know if these numbers are good or junk, but it did take several pulls to get saw started.

Thanks banshee1, those SKF 6119 seals are the preferred brand.

Vacuum tests should start at 15 “Hg, not 7 “Hg, and hold that level all day for new seals. That 15 ”Hg vac reading equals 7.4 psi on the positive side.

 

[3000 FPS]

There is only a 3 cc difference between the 3700 and 4000, 61cc vs 64cc. I wonder if anyone could tell tell the difference in performance. Esp. if you run comparable mufflers.

Well the 3700 is 60cc and the 3800 is 61 cc and the 4000 or 395 is 64 cc. I think the 3700 and 4000 which is a 4 cc difference does make a difference. After all we all know the saying. There is no replacement for displacement. If was only 3 cc then I would still believe it would make a difference. I have both saws but I have a tendency to mod them and so have no comparison in stock form.

 

[fossil]

I have all four models. You can feel a noticeable difference between all of them.

No mistake about it when you're running a 4000.

 

[Hoggwood]

I managed to take the 3.6 I picked up last May out today for the first time. It has been fairly sketchy out in the forests around here with the fires and restricted access. It was rescinded yesterday, so I went to check things out. There is a bit of a fuel delivery issue in the system, though. I managed to cut up a truck load, but it deserves a bit more time/supplies than the 20 min. once over I gave it initially.

Can anyone confirm these #'s look right? 5542 06081SM 068091VM

If I can't get the fuel system dialed in better, I will go after those seal numbers above. It appears there is a lot of life left in this saw.

 

[hotshot]

Can anyone confirm these #'s look right? 5542 06081SM 068091VM
If I can't get the fuel system dialed in better, I will go after those seal numbers above.

I’ll check my stock in a while, they were listed in an old “Seal finders here you go” thread. The small oil pump seal number was wrong in the Dichtomatic/TCM literature, but the correction is in the same old thread.

Copied & saved this from Kevin on the CRS thread too...and they do look correct from memory.

” Poulan 245/306

-PTO seal: 530001936. Dichtomatik 068091VM (dist by Rankin Industries). .687"x.937"x.135" (OEM measurements). .688"x.938"x.172"

-FW seal: 530019042. CR 5542 or 5541.

-Oil pump seal: 530019035. Dichtomatik 06081SM.”

 

[hotshot]

Hi Corey,
Those are all good numbers.

If you pressure/vacuum test it, prior to replacing crank seals, don’t forget to check that big bearing carrier/case o-ring 530019004 for leaks, as I’ve found many saws will leak there.

Poulan used an orange/brown plastic material (now old & brittle) for that seal, but it can be replaced with a standard SAE AS568 type buna-N or Viton o-ring. I can dig the McMaster-Carr bag out if you really need the size & dash number.

 

[banshee1]

There is only a 3 cc difference between the 3700 and 4000, 61cc vs 64cc. I wonder if anyone could tell tell the difference in performance. Esp. if you run comparable mufflers.

Maybe, but sometimes those 3cc can make a big difference. I may be reaching to far, but I'm hoping the cylinders wont be exact clones, maybe have better flow. If not I'll probably do a little port work myself.

 

[banshee1]

Thanks banshee1, those SKF 6119 seals are the preferred brand.

Vacuum tests should start at 15 “Hg, not 7 “Hg, and hold that level all day for new seals. That 15 ”Hg vac reading equals 7.4 psi on the positive side.

I didnt know that, though I shouldn't have been lazy and looked in to it myself. Will the higher vacuum pull the seals on to the shaft tighter giving the better numbers? I was hoping for better results on the pressure side though. While the saw is running obviously it wont have to hold crankcase pressure for seconds, more like .01 seconds so it'll never have a chance to lose pressure.
Was your comment about the bearing carrier seals to me? I didnt see any o-ring seals when I split the case and replaced the crank seals. Dont see that p/n on the ipl either.

Is Oregon p/n 32790x the current drum/sprocket for a 3700? My ipl shows 2 different p/n's for the drum/sprocket and I dont know which I should go after. The old 3700 should have a new one.

Thanks.

 

[hotshot]

I didnt know that, though I shouldn't have been lazy and looked in to it myself.
Will the higher vacuum pull the seals on to the shaft tighter giving the better numbers? I was hoping for better results on the pressure side though. While the saw is running obviously it wont have to hold crankcase pressure for seconds, more like .01 seconds so it'll never have a chance to lose pressure.

Was your comment about the bearing carrier seals to me? I didnt see any o-ring seals when I split the case and replaced the crank seals. Dont see that p/n on the ipl either.

Is Oregon p/n 32790x the current drum/sprocket for a 3700? My ipl shows 2 different p/n's for the drum/sprocket and I dont know which I should go after. The old 3700 should have a new one.

Thanks.

It’s not likely that the seal lip pulls tighter to the shaft under vacuum.

No, the last seal/o-ring comment was to Corey, sorry about the thread confusion, I just added/edited his name on it...

Yep, the aftermarket Oregon 32790X is the spur drive type for your 3700. If I remember correctly, the rim drive type is 28187X using a 3/8“-7T rim 68210. I like the rim drives best, but others prefer the spur, both work fine.

 

[redunshee]

Well the 3700 is 60cc and the 3800 is 61 cc and the 4000 or 395 is 64 cc. I think the 3700 and 4000 which is a 4 cc difference does make a difference. After all we all know the saying. There is no replacement for displacement. If was only 3 cc then I would still believe it would make a difference. I have both saws but I have a tendency to mod them and so have no comparison in stock form.

Well, we're almost correct. 3700 is 61cc and 4000 65cc. 4 cc difference per Acres. I guess if u guys can tell the difference in 4 cc's ur better than me.

 

[hotshot]

From an old Fossil post, he actually did the math! For the nitpicks... there’s 16.387 cc in one cu in, so you need to multiply his calcs by that. Also, there’s 10mm in one cm, & I rounded them to nearest 1/2 cc!

I agree w/ Bob, it’s not the bigger cc, but probably the shark gill muffler, larger exhaust port sizes & configuration you feel in the cut.

“Poulan 3400, -4000 saw stroke is 1.319"(33.5mm) and displacement

Volume of a cylinder V=πr2h (volume = pi X (radius squared) X height (stroke)

3400; 3.14159 X (1.81/2 )squared X 1.319 = 55.614 cc (56 cc)

3700 = 59.681 cc (60 cc)

3800 = 59.999 (60 cc)

4000 = 63.562cc“ (64 cc)

 

[OhioGregg]

Well the 3700 is 60cc and the 3800 is 61 cc and the 4000 or 395 is 64 cc. I think the 3700 and 4000 which is a 4 cc difference does make a difference. After all we all know the saying. There is no replacement for displacement. If was only 3 cc then I would still believe it would make a difference. I have both saws but I have a tendency to mod them and so have no comparison in stock form.

Im pretty sure the 3700 is 61cc, according to my Poulan advertising and decal on the saw. Can't speak for the 3800, never had one. I do run a 4000 and a 3700 a lot!! My most used saws. Never made any scientific tests or comparisons, but just seat of the pants feel from experience. They are close, but I will vote 4000 is stronger. None of my saws are ported or modded except for mufflers. I open those up by drilling the baffle holes and adding an outlet. Pretty much factory setups. And I use 20" bars on both. I do have a 4000 with a 24" on it, but havn't used that in ages.

Someone mentioned the air cleaner differences. I personally can't tell a difference. Whether its the wire flocked type or nylon mesh type. I like the 4000 style better, just me. I guess if one wants both worlds, a 61cc 3700 with a 4000 style air cleaner...They made a Poulan Pro 375, which I also have. Has 61cc with 4000 style accoutrements. LOL I think the 4000 is stronger than that one also.

Long time ago, probably 10 years ago, I did informal test of 61cc 3700 and the 60cc PP380. Made 3 cuts with each. The 3700 was slightly faster. Which surprised me,, cause the 380 is a higher reving ( newer style) saw. The differences in all these saws is minute in the real world cutting wood out in the woods. Im as happy as a pig in you know what with any of them.




Gregg,

 

[OhioGregg]

From an old Fossil post, he actually did the math! For the nitpicks... there’s 16.387 cc in one cu in, 10mm in one cm, & I rounded them to nearest 1/2 cc!

I agree w/ Bob, it’s not the bigger cc, but probably the shark gill muffler, larger exhaust port sizes & configuration you feel in the cut.

“Poulan 3400, -4000 saw stroke is 1.319"(33.5mm) and displacement

Volume of a cylinder V=πr2h (volume = pi X (radius squared) X height (stroke)

3400; 3.14159 X (1.81/2 )squared X 1.319 = 55.614 cc (56 cc)

3700 = 59.681 cc (60 cc)

3800 = 59.999 (60 cc)

4000 = 63.562cc“ (64 cc)

LOL Thats to much math for me...I'll take your word.

Gregg

 

[redunshee]

LOL Thats to much math for me...I'll take your word.

Gregg

I was never good at math. I do have a Randy Evans ported 4000. Unfortunately haven't had the chance to use it in Texas. Randy did say it would do better with a larger carb, though.


Sent from my SM-G935V using Tapatalk

 

[fossil]

LOL Thats to much math for me...I'll take your word.

Gregg

Good to see you back around Gregg. Still on the farm?

 

[3000 FPS]

You guys do know that everything in acres is not gospel. They have been wrong before on things.

I will trust the math of fossil. I do not believe that the 3800 is even listed on his site.
I also know that in the past people like MM tried to get him to correct a lot of the errors but he was just ignored.

 

[fossil]

I see he's done some updates recently. Maybe because he's retired form fixing saws. There are errors but still a fantastic resource.

 

[RedneckChainsawRepair]

I trust Tim's info over acres site all day. Acres's site is 50 50 shot most times. I take the info with a grain of salt and better double check everything. Also why I have Tim's info saved to a thread Poulan 4000 page 13 http://chainsawrepair.createaforum.com/poulan/poulan-4000/msg9686/#msg9686

Tim's info again saved.

I do believe the 3700 cylinder and the 3800 cylinders come out of the same die cast mold. The plated bore on the 3700 is 1.875" and the the bore on the bare 3800 cylinder is 1.880". The aluminum alloy would very likely be different as the bare bore requires the use of a high silicon aluminum alloy. I think the Chevy Vega was the first north American car to use this technology.

Poulan 3400, -4000 saw stroke is 1.319"(33.5mm) and displacement


Volume of a cylinder V=πr2h

3400 3.14159 X (1.81/2 )squared X 1.319 = 55.614 cc

(16.3871 cc per cu in)
3400 bore is 1.810"

3700 59.681 cc Bore 1.875"

3800 59.9999 cc Bore 1.880"

4000 63.562cc Bore 1.935"

 

[OhioGregg]

Good to see you back around Gregg. Still on the farm?

Yep, still here Tim. Went to Walmart week ago for first time in 2020. Geeez all the people and masks, was glad to be back home. One good thing about living out in the sticks, so to speak.

Gregg,

 

[s sidewall]

I trust Tim's info over acres site all day. Acres's site is 50 50 shot most times. I take the info with a grain of salt and better double check everything. Also why I have Tim's info saved to a thread Poulan 4000 page 13 http://chainsawrepair.createaforum.com/poulan/poulan-4000/msg9686/#msg9686

Tim's info again saved.

I do believe the 3700 cylinder and the 3800 cylinders come out of the same die cast mold. The plated bore on the 3700 is 1.875" and the the bore on the bare 3800 cylinder is 1.880". The aluminum alloy would very likely be different as the bare bore requires the use of a high silicon aluminum alloy. I think the Chevy Vega was the first north American car to use this technology.

Poulan 3400, -4000 saw stroke is 1.319"(33.5mm) and displacement


Volume of a cylinder V=πr2h

3400 3.14159 X (1.81/2 )squared X 1.319 = 55.614 cc

(16.3871 cc per cu in)
3400 bore is 1.810"

3700 59.681 cc Bore 1.875"

3800 59.9999 cc Bore 1.880"

4000 63.562cc Bore 1.935"

Only problem with the Chevy Vega is that it started burning oil. Then the went to case iron sleeves. A guy I worked with ages ago told me they had to send those plain bore blocks out to have them sleeved to fix the problem.

Steve from my moto g(7) play using Tapatalk