Mastermind meets the MS390

Arborist Forum

Help Support Arborist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Mastermind

Work Saw Specialist
Joined
Nov 21, 2009
Messages
36,449
Reaction score
42,855
Location
Tennessee
Here we go men, the saw no one wants to port. The MS390.

Very nice packing job!!!

attachment.php


attachment.php


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

attachment.php


attachment.php


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

attachment.php
 
Here we go men, the saw no one wants to port. The MS390.

Very nice packing job!!!

attachment.php


attachment.php


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

attachment.php


attachment.php


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

attachment.php

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.

attachment.php


Nice size and shape to the ports even stock.

attachment.php


attachment.php


attachment.php


attachment.php
 
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.

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. :(

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.

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

You're a glutton for punishment:)

:msp_biggrin:

Go Randy :msp_thumbup:

:msp_biggrin:

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!

It's easier to take more out than it is to add metal back in. If it needs more...... :)
 
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.


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.
 
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.

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:
 
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:

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.

attachment.php


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]
 

Latest posts

Back
Top