Mastermind meets the MS390

[Jon1212]

Jeeze Randy, You actually DO know what your're doing

Sheesh! That's a relief......

 

[stihlaficionado]

Sheesh! That's a relief......

Now I can mail him my 1973 B & S 3 1/2 hp mower . It needs a tune up

 

[Mastermind]

Again, here's the stock numbers on this saw. They really aren't bad for a stock saw. The problem these saws have IMHO is the restricted muffler. With just a modest muffler mod this saw came alive before I widened the ports.

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

After I put it back together:

Intake Duration: 165°
Exhaust Duration: 164°
Blowdown: 25°

I lowered the intake port to gain 10°, and as a result of just cleaning up the casting I gained 2° on the exhaust. The transfers are untouched so I got an extra degree of blowdown.

The finished exhaust port. I just carried the width all the way out to the flange, the top and bottom are in the stock location.

Finished intake. I don't get the intake quite as smooth as the exhaust in hopes that it really matters.

Ready to go back together. Notice the ring is tagged, this is to be sure I don't swap the rings around. It should go back together and not need to seal the rings this way, at least that's the plan.

Note the grease on the crank. I always use a bit on the seals. When reusing the old seals I put a dab of threebond around them. This isn't necessary when new seals are used.

 

[Jon1212]

Thanks again Randy, I can't wait to get it back, and run it. Let the haters hate, the world they live in is flat.

 

[audible fart]

Thanks again Randy, I can't wait to get it back, and run it. Let the haters hate, the world they live in is flat.

+1. This thread has clearly proved once and for all that the MS390 is an ultra powerful, moddable work saw. And for the last time Sawtroll, stop sending me PMs. My MS390 is not for sale.

 

[tbone75]

Great job as always Randy

 

[Currently]

Subscribing ....

Wondering if it will match a 362 in power?

 

[Art Vandelay]

Hows about i mod your MS211 with a steamroller.

It will hurt the steamroller. :biggrinbounce2:

 

[Mastermind]

More pics...

Starting the bolts in the bottom first. They go thru the tanks/case into the engine. I get them started but don't tighten them just yet.

Next, run the rear bar stud in. then tighten the case bolts.

Here's some more pics of the saw. I'll get it finished tomorrow and hopefully get to post an "after" Video.

 

[wendell]

Does that mean we got to git married now that we have entered each other???:biggrin:

You southerners do have your own unique way of living. I think I may be reconsidering my trip to the TAMOK GTG. :msp_scared:

Randy, how is your career as a hand model working out?

 

[Mastermind]

You southerners do have your own unique way of living. I think I may be reconsidering my trip to the TAMOK GTG. :msp_scared:

Randy, how is your career as a hand model working out?

Welp Wendell my friend. Things were fine till I cut that thumb off with a skil saw. See that scar on it??? :hmm3grin2orange:

It don't bend anymore either, but that comes in handy for poking some smart mouth in the eye.

 

[WoodChuck'r]

Subscribing ....

Wondering if it will match a 362 in power?

Not a chance.

 

[MechanicMatt]

Welp Wendell my friend. Things were fine till I cut that thumb off with a skil saw. See that scar on it??? :hmm3grin2orange:

It don't bend anymore either, but that comes in handy for poking some smart mouth in the eye.

You should be happy they re-attached it. I have a friend that I watched cut his thumb off at the first joint with a table saw. Idiot was to lazy to swap the rack over and the board kicked out and in went his thumb. Well any way they didn't re-attach it and now he has this ugly nub. Ill always remember picking up his thumb and putting it in a zip lock bag before driving off to the ER.

 

[audible fart]

Not a chance.

Mastermind put you up to this "lowering expectations" crap, and frankly i'm disappointed in you.
So mastermind, is this the first perfectly good MS390 you've transformed into a time bomb, or is there a trail of grenaded MS390s that led you to this one hoping this time would be different?

 

[WoodChuck'r]

Mastermind put you up to this "lowering expectations" crap, and frankly i'm disappointed in you.
So mastermind, is this the first perfectly good MS390 you've transformed into a time bomb, or is there a trail of grenaded MS390s that led you to this one hoping this time would be different?

I just announced in the 441 thread that I have to poop.

I'll be back shortly. Hopefully the roids don't bug me too much when I push. Nothing like wiping up a bunch of ketchup when yer done.....

 

[Mastermind]

You should be happy they re-attached it. I have a friend that I watched cut his thumb off at the first joint with a table saw. Idiot was to lazy to swap the rack over and the board kicked out and in went his thumb. Well any way they didn't re-attach it and now he has this ugly nub. Ill always remember picking up his thumb and putting it in a zip lock bag before driving off to the ER.

They put it back on and I have complete feeling in it. It will not bend at all though, I sawed diagonally through the joint. It may have been better had they left it off, it gets in the way and ends up getting stubbed a lot.

Mastermind put you up to this "lowering expectations" crap, and frankly i'm disappointed in you.
So mastermind, is this the first perfectly good MS390 you've transformed into a time bomb, or is there a trail of grenaded MS390s that led you to this one hoping this time would be different?

I just hope it still runs......

 

[Mastermind]

I just announced in the 441 thread that I have to poop.

I'll be back shortly. Hopefully the roids don't bug me too much when I push. Nothing like wiping up a bunch of ketchup when yer done.....

Need em packed back in???

 

[WoodChuck'r]

Oh my goodness that's funny.

 

[Mastermind]

Oh my goodness that's funny.

Marvel of mechanical engineering. :msp_sleep:

 

[Warped5]

Marvel of mechanical engineering. :msp_sleep:

Looks like a 'Steely Dan!'