# Dangers of muffler mods?



## Pallet Pete (Apr 2, 2012)

I have a poulan pro 4620 that is a decent saw and I have discovered that the mufflers are only 10 bucks online. The tinker in me wanted to modify the muffler and see what happens soooo I drilled a hole in the top left side and wow that baby cuts like a hot knife through butter know ! My question is was that stupid? I could not find any info on how to do this so I just winged it.  

Pete


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## pen (Apr 2, 2012)

Looks to me like you are going to send a lot of exhaust (heat) towards your chain brake and handle.


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## Pallet Pete (Apr 2, 2012)

pen said:


> Looks to me like you are going to send a lot of exhaust (heat) towards your chain brake and handle.


 
I have been trying to figure out a way to put a tube on it then direct it forward with a spark screen. My other idea is to put to 3/8 inch holes on the front with tubes welded on with spark screens ???

Pete


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## lukem (Apr 2, 2012)

Pallet Pete said:


> I have been trying to figure out a way to put a tube on it then direct it forward with a spark screen. My other idea is to put to 3/8 inch holes on the front with tubes welded on with spark screens ???
> 
> Pete



I would do that but skip the tubes and spark screens.


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## surviverguy (Apr 2, 2012)

If you have a mig welder- just weld a tube over the hole to direct the hot gases forward and slightly upward.


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## Pallet Pete (Apr 2, 2012)

surviverguy said:


> If you have a mig welder- just weld a tube over the hole to direct the hot gases forward and slightly upward.


Yes I have a mig welder and that was the original plan to have a tube go off the side and forward. Is there a special type of metal tube I should use or will any old piece work? 

Pete


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## surviverguy (Apr 2, 2012)

Pallet Pete said:


> Yes I have a mig welder and that was the original plan to have a tube go off the side and forward. Is there a special type of metal tube I should use or will any old piece work?
> 
> Pete


If a magnet will stick to it (ferrous) it'll work...even galvanized works, but beware of and avoid the dangerous fumes. Some thin sheet metal would even work...


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## HittinSteel (Apr 2, 2012)

You can probably make the hole a little larger before you add the tube. Did you richen the H screw a little?


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## surviverguy (Apr 2, 2012)

2 cycle engines need some flow resistance (back-pressure) to operate properly. Make the hole too big and it'll run like chit. You said, "it's like a hot knife thru butter now", so just direct the exhaust where you want it to go. sheet metal might even work well in combination with a tube...lots of options there...let creativity and common sense be your guide. Good luck and post the results.


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## wkpoor (Apr 3, 2012)

Not sure where right now but the screw on deflectors and screens can be bought new for muffler mods. The saws I bought modded all have them. They make a mod look factory. Adding a port is good but gutting the muffler is good also in conjunction with an extra port. Seems most saws respond favorably to a muffler mod but to what extent is a case by case basis. And then there is the extra noise some people don't care for.


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## MasterMech (Apr 3, 2012)

Retune the carb before you go cutting again.  You're running lean and need to compensate for the additional airflow.


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## Pallet Pete (Apr 3, 2012)

I richened it a bit on the fuel it smells a bit now but man does it respond to the trigger. I was having a problem with it bogging in the wood no matter what before and now it doesn't bog in the wood all. I am looking online for an air deflector today because that would be perfect for the saw. Thanks guys you all rock ! I will put up the finished pics as well it is in pieces on my work bench at the moment.

Thanks 
Pete


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## ScotO (Apr 4, 2012)

I will venture to say that most every piece of modern  machinery made can be modded to run a lot better and with more power by a simple muffler mod such as the one you performed.  One does have to be careful not to overdo it, though.  Like MM said,  richen your hi mixture screw to compensate for the added airflow.   Keep us posted on your mod.


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## smokinj (Apr 4, 2012)

Looks pretty good. I just blow a muff cover into pieces last week. Factory welds gave out.


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## Pallet Pete (Apr 4, 2012)

Well guys I have a couple of banding crimps from work that I am gonna reshap and weld to the muffler as an air deflector. I will be working on it this weekend so I will let you know how it goes! pics to come tonight I hope.

Thanks guys 
Pete


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