Nik's Poulan Thread

[James Miller]

I picked up this 3.7 for $20 last weekend. Someone dropped a tree on the rear handle. Put a rear handle on from a 3400 parts saw and new fuel lines and filter. Saws runs perfectly but I'm considering a few mods. MM, bg delete. I have a question about the intake block between carb and intake port. It's offset towards the recoil side of the intake port can this be sanded to give a more direct shot from the carb to the intake port? Just looking at it there has to be gains to be had from a little work. Just wondering if it's worth the time?

 

[Todd Loosli]

You can get it a little smoother and blended with whatever you have to cut with
This needs sanding to finish

 

[James Miller]

Thank you sir. Figure I have the one off the parts saw if I mess this one up so might as well see what I can do.

 

[3000 FPS]

Yep you can smooth up that intake. There are usually some areas inside that are rough from casting process. It is all the mods together that add up to make a better running saw.

When you take that cylinder off for the gasket delete take a burr and grind the tops of the transfers to point toward the intake. Not a lot just a little so the fuel mixture will flow better in that direction.

 

[Todd Loosli]

I wish I understood a little better what part of the port you are talking about, a picture or a drawing would help. If you grind the top you raise the port and if the upper side then how much. Need help but I like the idea.

 

[James Miller]

I wish I understood a little better what part of the port you are talking about, a picture or a drawing would help. If you grind the top you raise the port and if the upper side then how much. Need help but I like the idea.

I agree. I was just going to leave the jug alone as I have not tried port work on a saw before.

 

[James Miller]

Short video of first time out today.

 

[Jethro 2t sniffer]

Short video of first time out today.

Sounds good

 

[3000 FPS]

I wish I understood a little better what part of the port you are talking about, a picture or a drawing would help. If you grind the top you raise the port and if the upper side then how much. Need help but I like the idea.

Here is a picture. Not my cylinder or my work but from someone else who did some nice work. This is a nice example of what I was referencing to. Do not raise the ports, but point them toward the intake.

 

[Jethro 2t sniffer]

Here is a picture. Not my cylinder or my work but from someone else who did some nice work. This is a nice example of what I was referencing to. Do not raise the ports, but point them toward the intake.

View attachment 770566

How much better did it run?

 

[Todd Loosli]

Thanks that makes it very clear to understand.
I haven't seen very much port work so this is great information, nothing like a good picture.

 

[James Miller]

Sounds good

Thank you. Seems to be a big difference between it and a 3400. More then I expected.

 

[Jethro 2t sniffer]

Thank you. Seems to be a big difference between it and a 3400. More then I expected.

Aww well that's good I'd like to try those models I have a 4000 and probably 1day will need a 3700 top end on it so good to see how they run. Only a couple cc difference but this porting talk sounds good for getting those couple cc power back

 

[James Miller]

Aww well that's good I'd like to try those models I have a 4000 and probably 1day will need a 3700 top end on it so good to see how they run. Only a couple cc difference but this porting talk sounds good for getting those couple cc power back

I've read a few times on the forums that a 3700 with the muffler opened up will run with a stock 4000.

 

[Jethro 2t sniffer]

I've read a few times on the forums that a 3700 with the muffler opened up will run with a stock 4000.

Yeah not alot in it. Ya wonder why they bothered really

 

[Maintenance supervisor]

My version of "Going Green "
Bonus 4200 bow , package deal

 

[Big Dan]

I've read a few times on the forums that a 3700 with the muffler opened up will run with a stock 4000.

I've got a stock 4000 and a mildly ported 3700 with a muffler mod and running them back to back there is still a difference,the 4000 has more torque and will cut a little faster.

 

[3000 FPS]

How much better did it run?

Well it is hard to say. I dropped the cylinder, opened the muffler, port matched the exhaust port on cylinder to the muffler, cleaned up the intake, did the work on the transfer ports similar to the picture, opened the intake port some and did not lower or raise it, and did the same to the exhaust port. Then advanced the timing.
Was on a 3700 and when done I used a tach and got 13000 rpm with bar and chain. Still have the saw and it still runs great. I did not use a timing wheel on it and did not go crazy with the porting. I used a piece of sand paper on all the edges of the ports to make sure they were a little rounded with no sharp edges for rings to hang up on.

 

[Jethro 2t sniffer]

Well it is hard to say. I dropped the cylinder, opened the muffler, port matched the exhaust port on cylinder to the muffler, cleaned up the intake, did the work on the transfer ports similar to the picture, opened the intake port some and did not lower or raise it, and did the same to the exhaust port. Then advanced the timing.
Was on a 3700 and when done I used a tach and got 13000 rpm with bar and chain. Still have the saw and it still runs great. I did not use a timing wheel on it and did not go crazy with the porting. I used a piece of sand paper on all the edges of the ports to make sure they were a little rounded with no sharp edges for rings to hang up on.

Cool man sounds like you did good. Thanks for writing that up I guess we'd need to get into the port mapping and the real nitty gritty to do much else

 

[3000 FPS]

Cool man sounds like you did good. Thanks for writing that up I guess we'd need to get into the port mapping and the real nitty gritty to do much else

The main thing is to have some fun with it. I did not want to get all technical with all the mods and I still keep it that way. The Countervibe series of saws are sure great.