Mastermind meets the MS390

Treestuff
Rugged made
Wesspur
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Mastermind

Mastermind

Work Saw Specialist
Joined
Nov 21, 2009
Messages
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Location
Tennessee
Here we go men, the saw no one wants to port. The MS390.

Very nice packing job!!!

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Good looking saw. In great condition, good compression, perfect candidate for a woods port.

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I can see why these saws are so weak in stock form. This muffler opening is very restrictive.

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Mastermind said:
Here we go men, the saw no one wants to port. The MS390.

Very nice packing job!!!

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attachment.php


Good looking saw. In great condition, good compression, perfect candidate for a woods port.

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I can see why these saws are so weak in stock form. This muffler opening is very restrictive.

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Click to expand...

ewww...an orange handled Stihl
 
I was one that was not sure about muffler mods. I didn't think there was that much improvement. The I came across an MS310. Similiar to a MS290. I didn't impress me. I like the MS290 and the 310 was just too close. Then I decided, let's try it. Open up the muffler and see what happens. Now I'm all for modding a muffler. I have not tried a port job yet, gathering the tools to start this next step. It woke that saw up a ton. I can't wait to see the gains with a woods port here. I'm on the fence. Keep us posted.
 
ummm didn't the 390 have a decompression on it? I don't see it on that one? I would measure the bore and make sure that is what you have. The tag on the flywheel can easily be replaced.
 
Open that muffler more! I did the same thing to my 029S but drilled similar holes in the deflector as well and it woke my saw up even more!
 
Stripped to the bones. That's the only way to get to the ports. It's definitely harder to work on than a pro series.

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Nice size and shape to the ports even stock.

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sefh3 said:
I was one that was not sure about muffler mods. I didn't think there was that much improvement. The I came across an MS310. Similiar to a MS290. I didn't impress me. I like the MS290 and the 310 was just too close. Then I decided, let's try it. Open up the muffler and see what happens. Now I'm all for modding a muffler. I have not tried a port job yet, gathering the tools to start this next step. It woke that saw up a ton. I can't wait to see the gains with a woods port here. I'm on the fence. Keep us posted.
Click to expand...

I ran it after the muffler mod and can tell you this saw likes to breathe. The muffler is really stopped up stock. I'll get a pic of the deflector, noticed I missed it. :(

sefh3 said:
ummm didn't the 390 have a decompression on it? I don't see it on that one? I would measure the bore and make sure that is what you have. The tag on the flywheel can easily be replaced.
Click to expand...

It's a 390 the bore is 49mm. The owner bought it new as well.

blsnelling said:
You're a glutton for punishment:)
Click to expand...

:msp_biggrin:

AUSSIE1 said:
Go Randy :msp_thumbup:
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:msp_biggrin:

Stellarex said:
Open that muffler more! I did the same thing to my 029S but drilled similar holes in the deflector as well and it woke my saw up even more!
Click to expand...

It's easier to take more out than it is to add metal back in. If it needs more...... :)
 
nmurph said:
what happened to the 401????? That's the one I want to see.

BTW, open that muffler some more. I would double the size of the lower slots.
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The 401 is still on the shelf, it's my own saw so I never get time to work on it. :cry:

The lower slot are outside the baffle so I'm just ignoring them for now.
 
audible fart said:
Just throw that piece of #### in the trash can. Unless you buy a 660 instead all the "loggers" around here that are actually aging homeowners with B cups will think poorly of your social standing.
Click to expand...

I will tell you this my flatulent friend.

This saw is an overweight pig stock. When I'm done with it it will be a different animal though. :hmm3grin2orange:
 
Mastermind said:
I will tell you this my flatulent friend.

This saw is an overweight pig stock. When I'm done with it it will be a different animal though. :hmm3grin2orange:
Click to expand...

Jon1212 is going to sue you. Because the MS390 is a well known useless piece of #### that nobody will ever be satisfied with. It's going to respond initially to these mods and burn up within a day or two.
 
The timing numbers are really good imho.

Intake Duration: 155°
Exhaust Duration: 162°
Blowdown: 24°

It's mostly cleaned and ready to go.

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Here's a couple of videos of the saw bone stock. The wood is 20" hickory that's as hard as woodpecker lips. The chain is Oregon full chisel, freshly sharpened with the rakers at .030.

[video=youtube;fBPaFkDF2mA]http://www.youtube.com/watch?v=fBPaFkDF2mA[/video]

[video=youtube;wyTn8avl-Os]http://www.youtube.com/watch?v=wyTn8avl-Os[/video]

This is my ms460 in the same piece of wood. Yeah it's some hard stuff.

[video=youtube;stYkw90VCp4]http://www.youtube.com/watch?v=stYkw90VCp4[/video]
 

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