Mastermind meets the MS390

Mastermind · Aug 18, 2011

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

Very nice packing job!!!

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

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

stihlaficionado · Aug 18, 2011

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

Very nice packing job!!!

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

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

ewww...an orange handled Stihl

sefh3 · Aug 18, 2011

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.

roncoinc · Aug 18, 2011

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

Very nice packing job!!!

Thats because nobody cares !! :msp_biggrin:

Mastermind · Aug 18, 2011

Working over the muffler first.

sefh3 · Aug 18, 2011

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.

blsnelling · Aug 18, 2011

You're a glutton for punishment

AUSSIE1 · Aug 18, 2011

Go Randy :msp_thumbup:

Stellarex · Aug 18, 2011

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!

Mastermind · Aug 18, 2011

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.

Nice size and shape to the ports even stock.

Art Vandelay · Aug 18, 2011

Bout time AF got his 390 Mastermoobed. :clap:

nmurph · Aug 18, 2011

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.

Mastermind · Aug 18, 2011

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.

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.

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

blsnelling said:
You're a glutton for punishment

:msp_biggrin:

AUSSIE1 said:
Go Randy :msp_thumbup:

: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!

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

Mastermind · Aug 18, 2011

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.

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 · Aug 18, 2011

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.

Mastermind · Aug 18, 2011

Art Vandelay said:
Bout time AF got his 390 Mastermoobed.

This saw belongs to our off-topic friend Jon1212.

AF would have to pay more.

Mastermind · Aug 18, 2011

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.

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:

audible fart · Aug 18, 2011

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:

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.

Mastermind · Aug 18, 2011

The timing numbers are really good imho.

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

It's mostly cleaned and ready to go.

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]

Sport Faller · Aug 18, 2011

Jee-zusss that is some hard ####, even though, that stock 39 is a bit of a turd

I'm interested in the "after" video :rock:

Mastermind meets the MS390

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