TreeVets New MS661C

[blsnelling]

For those that are interested, I thought I do a thread on Dave's new 661. I won't start on the mods until this weekend, but here's his new saw. @treevet

 

[treevet]

ooo I like this thread better than mine.

 

[JeffGu]

Damn good looking saw.

 

[BeesandTrees]

You have the baby of that saw going also, a little 150. Excited!

 

[blsnelling]

You have the baby of that saw going also, a little 150. Excited!

And your 201. I picked up your 150 on Wednesday.

 

[oldoakman]

Not to rain on anyone's parade, but you would think that with all the guys doing to mods on their saws that Stihl wod wake up and just make them that way.

 

[JeffGu]

I think the EPA would frown on that.

 

[Dblehron]

And leaning out a 2 stroke could have less than desirable consequences.

 

[blsnelling]

Making progress. More to come.

Here is the saw bone stock. It only made one cut before this video was shot. They run mighty nice for a stock saw.

 

[blsnelling]

Pulling the flywheel.

The key is a little over .075" thick.

I file down the portion that sticks out of the crank so that the flywheel can be indexed CCW in order to advance the ignition timing.

 

[blsnelling]

Squish from the factory was .033"-.034".

Once I know the squish, the cylinder comes off and I can do the machine work.

I just touch the bottom of the piston skirts in order to make sure they're square with the crown.

I then turn a popup on the piston crown. I give the edge of the popup a 45° angle.

 

[blsnelling]

This is just one of the rough cuts on both the piston and cylinder.

 

[blsnelling]

Here you can see where I did a little porting on the transfer intake duct.

 

[blsnelling]

Squish after machining was a strong .020", right where I wanted it.

I check the squish on all 4 corners. This is partly to make sure the popup isn't too close to the edge of the combustion chamber.

Setting up the degree wheel.

 

[blsnelling]

I've found through testing that completely removing the baffler is the best way to go.

I will cut a new screen with more open space in it. If this weren't a daily work saw I'd also add gills to both sides of the muffler cover. In this case, I'd rather keep the volume down a little.

 

[blsnelling]

My photo editing software does some weird stuff to cylinder pictures. Please ignore the "dark marks".

 

[treevet]

Genius...like making a Stradivarius.

 

[treevet]

Making progress. More to come.

Here is the saw bone stock. It only made one cut before this video was shot. They run mighty nice for a stock saw.

Pretty ballsy stock. That ash wood is very dry. Takes a strong effort to go thru that easily. Full chisel?

 

[blsnelling]

Pretty ballsy stock. That ash wood is very dry. Takes a strong effort to go thru that easily. Full chisel?

Yes. It's the new RS chain that came with it.

The saw is done. I'm uploading more pics and videos now. It'll be a little while yet.

 

[blsnelling]

She's done and runs fantastic.

I only remove the casting lines here.

All done and back together.