Poulan Pro 4218 muffler mod difference

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My experience so far has been frustrating. It started and ran ok with a being little bit lean yesterday. I thought well it should cut wood. I'll get the splined carb tool later. Tried cutting this morning and it wouldn't run except with the choke on. So gave up on it and used my Echo 400. Called a local poulan dealer to see if he had the tool. He said he might have an extra but bring it by and he would adjust it. He seems like a really good guy. I told him I would stop by this afternoon. I really wanted to cut some wood this morning even if it wouldn't be at it's best (lean and skip chain).
 
My experience so far has been frustrating. It started and ran ok with a being little bit lean yesterday. I thought well it should cut wood. I'll get the splined carb tool later. Tried cutting this morning and it wouldn't run except with the choke on. So gave up on it and used my Echo 400. Called a local poulan dealer to see if he had the tool. He said he might have an extra but bring it by and he would adjust it. He seems like a really good guy. I told him I would stop by this afternoon. I really wanted to cut some wood this morning even if it wouldn't be at it's best (lean and skip chain).

Better to get it tuned up first, not risk running it too lean. Besides, if the dealer is a good guy you might learn a new trick or two, maybe even pick up a bargain while you're there.

Get that tool if you can. It is 10 times easier to adjust the carb with that tool vs. a slotted screwdriver.
 
I got a little lesson on tuning these things yesterday. Found out it dont like it when you turn the L screw in to it drops rpms then out till it drops again and then split the difference. Way too rich, blubbers out of the cut and sometimes dies.

The trick is to screw it in till it about dies then just out far enough to bring the rpms back up. Good clean throttle responce and all is good this way.
 
I went by the dealer. He did some adjusting and it sounded much better. He is ordering the splined screwdriver so I will have one next week. Also got a loop of carlton semi chisel. Will try cutting again tomorrow.
 
Sounds like your on your way. Glad the dealer could help you out. If he did it right you will be much happier with it now.

I'm finding these to be very picky with carb settings. A little is alot when adjusting them. They dont seem to mind so much being a little rich on the high side but there very touchy on the low side.
 
my muffler mod trick to the 4218 and 4620's

The mufflers on the poulan saws today are very restrictive this is how I muffler mod the muffler in quick fashion.

First, the internal baffle is a joke, so just enlarging the outlet is not going to do much, unless you did what Mark did which he was able to get under the baffle but may have compromised the structural integrity of the muffler.

I got around it by drilling out the muffler tubes that mount the muffler to the head. I believe those tubes have more holes than the factory baffle has.
What's nice about this is you can really tune the saw and you can also rotate the holes so the holes are not directly in the path of the exhaust gas as it leaves the engine. The exhaust still has to bounce off the front deflector first then gets dispersed through the holes. Makes for a quieter muffler that still flows. Still looks factory, keeps everything under the spark arrestor....the deflector should be modded as well.

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The mufflers on the poulan saws today are very restrictive this is how I muffler mod the muffler in quick fashion.

I got around it by drilling out the muffler tubes that mount the muffler to the head. [/IMG]

VW,

How did you get those tubes out of the muffler? Do they just slide out, or do you have to pry / cut them out?

We just bought a new house in October 2011 and the previous homeowner was nice enough to leave behind a Poulan 4218 that was in pieces... The saw was maybe used once (twice at best)... It is brand spanking new. Not sure why he had it apart in the first place. My best guess would be to try to fix the leaking bar oil if the saw is left sitting too long. He apparently could not get the chain brake / spring assembly back together. It took the work of two people, but once it was back together, it fired right up. Not thrilled about an 18" bar, but I can't come to replace it with a shorter one because it is brand new. I will wait until that one wears out and then do something.

Till then, I am going to need to get a little more grunt out of the saw as it will become a loaner saw.
 
I helped a friend with one of these 4018, I left everthing in the muffler stock, and just added two small flat washers under the deflector shield mounting post, to space out the deflector from the muffler body. Then ran a bread of Ultra grey rtv around the seam between the deflector and the body and smoothed it with my finger. I did omit the spark screen. Does seem to run free-r and looks stock.
 
VW,

How did you get those tubes out of the muffler? Do they just slide out, or do you have to pry / cut them out?

We just bought a new house in October 2011 and the previous homeowner was nice enough to leave behind a Poulan 4218 that was in pieces... The saw was maybe used once (twice at best)... It is brand spanking new. Not sure why he had it apart in the first place. My best guess would be to try to fix the leaking bar oil if the saw is left sitting too long. He apparently could not get the chain brake / spring assembly back together. It took the work of two people, but once it was back together, it fired right up. Not thrilled about an 18" bar, but I can't come to replace it with a shorter one because it is brand new. I will wait until that one wears out and then do something.

Till then, I am going to need to get a little more grunt out of the saw as it will become a loaner saw.



They just pop out, fall out once you remove the muffler.
 
I helped a friend with one of these 4018, I left everthing in the muffler stock, and just added two small flat washers under the deflector shield mounting post, to space out the deflector from the muffler body. Then ran a bread of Ultra grey rtv around the seam between the deflector and the body and smoothed it with my finger. I did omit the spark screen. Does seem to run free-r and looks stock.

If thats all you did you left alot on the table Those slots coming out from around that diffuser are very restrictive.

I have done a couple of the outer deflectors with a second opening and that seemed to help alot as well.
 
If thats all you did you left alot on the table Those slots coming out from around that diffuser are very restrictive.

I have done a couple of the outer deflectors with a second opening and that seemed to help alot as well.


I agree, you need to open the outlets before the inside baffle, the inner deflector/baffle/diffuser is a joke
 
I helped a friend with one of these 4018, I left everthing in the muffler stock, and just added two small flat washers under the deflector shield mounting post, to space out the deflector from the muffler body. Then ran a bread of Ultra grey rtv around the seam between the deflector and the body and smoothed it with my finger. I did omit the spark screen. Does seem to run free-r and looks stock.
Miles86 how does the Ultra grey rtv hold up to muffler temperatures ?
 
Howdy-

It works well and is fuel resistant unlike the permatex regular rtv. I avoid rtv silicone and use either Hylomar, motoseal, or anaerobic gasket maker.
 
I know this is an old post, but if anyone has some pictures of the mods they did to the mufflers I would love to see them. I have about 6 of these saws to play with and would like a better idea of where to start. Thanks
 
I know this is an old post, but if anyone has some pictures of the mods they did to the mufflers I would love to see them. I have about 6 of these saws to play with and would like a better idea of where to start. Thanks

Almost a year later than you, but I'm in the same boat! I see lots of threads that -used- to have photos, but they're all gone. I'm wondering if I should open up the stock slots, or do the whole "dremel another exhaust port in the side" thing. If opening the stock ports, removing the bolt tubes, and putting a spacer for the stock diffuser works, I'd rather do that and maintain a stock appearance. If the dremel/2nd port thing works better, then I'll just do that.
 
Agree on the missing pictures. Would love to see what these guys are talking about!
Almost a year later than you, but I'm in the same boat! I see lots of threads that -used- to have photos, but they're all gone. I'm wondering if I should open up the stock slots, or do the whole "dremel another exhaust port in the side" thing. If opening the stock ports, removing the bolt tubes, and putting a spacer for the stock diffuser works, I'd rather do that and maintain a stock appearance. If the dremel/2nd port thing works better, then I'll just do that.
 

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