Mastermind Meets The MS461

[Mastermind]

This is a thread I did a couple of years ago for the T-Bone raffle.



I'll be adding to this thread over the course of the day as I take it apart and modify it.

 

[Mastermind]

The HD2 air filter is great......I do wish they would have used the air injection that they used on the 441 on this saw though.



Looks like a 460 here huh?

 

[Mastermind]

Let's tear into this thing.





Please excuse my rough looking appearance, I'm growing my winter beard and am in that grungy looking mid point stage.





Please ask any questions you want, no matter how elementary you may think they are.

 

[Mastermind]

 

[Mastermind]

 

[Mastermind]

Now, we start getting to mods. First thing I do is defeat the carb limiters.



The tool I'm using here is just an old #1 Phillips screwdriver with a drywall screw brazed to the end of it.





Trimming the tab off....



Reinstalling the limiter caps. It's easier to "find" the adjustment screws with the saw running with these in place.

 

[Mastermind]

Now moving on to the the coil and timing mods.





Here I'm popping the wire off using the blade of a screwdriver rather than pulling it off. Many times, the spade connector can be damaged by pulling it off.





I use a double ended, threaded flywheel puller on most Stihl saws. It's just a cheap Moped tool from ebay.



Pop......and she's off.

 

[Mastermind]

I'm removing .020 from the edge of the key.

 

[Mastermind]

Coils.....

The MS461 is rev limited to 13,500. To make the saw unlimited I use either a 460, or 660 coil. On this saw, I have a 660 coil to use.





As you can see in this pic, all three holes don't line up using the 660 coil. On the 460 coil there are only two bolts as well, so I don't worry about this.

 

[Mastermind]

Let me back up just for a second. Here's a shot of the flywheel key.



See how the area I cut is on the right side? That will make the flywheel rotate counter-clockwise further than it was from the factory. I've found that by taking .020 from the key that I get around 6° advance.

Now here I'm holding the flywheel against the rope I'm using as a stop, then I tighten the flywheel nut as tight as I can while holding it like this.



After it's snugged up to hold the flywheel in place, I rotate the engine to catch the stop in a way that allows me to finish tightening the flywheel.

 

[Mastermind]

Moving on.....







Damn that old tattoo gets uglier every year.

 

[Mastermind]

Here's that baffle/stuffer/do-hicky thing that lots of people wonder what is for. It don't bother me, so I don't bother it.

 

[Mastermind]

Now we begin to port it.

 

[Mastermind]

Now to set up for the squish mod.....

I get a lot of questions about how this is done, so I'll spend some time here.

In this pics is a few of the plates I've made to mount various cylinder on.



This is the one that the 461 jug uses. The hole and divot are there to allow the stud and shroud boss to have clearance.



This is all there is to mounting the jug to the plate......simple really.



Then the plate is mounted in an independently adjustable four jaw chuck, on the lathe. That allows me to center the bore with the spindle.

 

[Mastermind]

Another view of the jug mounted.



Here I'm setup with a long reach indicator to check runout.



I made a couple of videos with more detail on the centering process.........if I post them y'all won't make fun of the way I talk will you?

 

[Mastermind]

I make pencil marks on the bed to go back to when I move the carriage. Anything to make it easier.....





Here's a shot of indicating the bottom of the jug....



And how that is adjusted.

 

[Mastermind]

 

[Mastermind]

A video for your enjoyment while I'm cutting this squish band.

 

[Mastermind]

Here's the boring bar setup I use.



Getting some spin on.





And one with flash......



Done. .040 gone from the quench area.....

 

[Mastermind]

Getting ready to check squish. I've got a few rolls of .030" soft solder that I picked up on ebay awhile back, that's why I twist this stuff up like this. That and it's real handy to be able to make it any size I need. I should point out here that if your solder is too large it will give you a false reading.....



This bolt holds that flange/stuffer hicky, and it is higher than the case where the jug bolts down. If you try to delete the base gasket on the 461, you must grind the head of these two bolts down about .020".



We now have .065" squish clearance. We'll want to take .040" off the base to end up at .025.