Project Stumpbroke How I do it

Thought a few of ya's might want a lil more in depth look at how I port a saw. I'll be using my current project a Stihl MS460 to illustrate. Feel free to ask ?'s. I'll do my best to answer. I do want to add this is not the only way to do it, just the way I do it.

Just a run of the mill well used MS460 with a couple of new parts to go with it.


Normal grit & grime from being used for it's intended purpose.


The first step is to get everything as clean as possible. I have a parts washer outside the shack that the saws take a bath in.

Stump, you must have one hellva solution in the parts washer...that stuff cleans! mind sharing the mixing ratio and contents.Looks like gloves need to be worn with face shield.....Later Jody

opcorn:

jhutton said:

Stump, you must have one hellva solution in the parts washer...that stuff cleans! mind sharing the mixing ratio and contents.Looks like gloves need to be worn with face shield.....Later Jody

Click to expand...

Yea... How much just to clean the saw??? I got this really nasty thing...
Well...:msp_sneaky:

jhutton said:

Stump, you must have one hellva solution in the parts washer...that stuff cleans! mind sharing the mixing ratio and contents.Looks like gloves need to be worn with face shield.....Later Jody

Click to expand...

It's just parts cleaner from the local hardware store. I think it's just mineral spirits. I just use a brush & some elbow grease to get em clean. I usually wear gloves, but sometimes I don't. It's not all that harsh.

Hedgerow said:

Yea... How much just to clean the saw??? I got this really nasty thing...
Well...:msp_sneaky:

Click to expand...

Some stuff can't be washed away..........:hmm3grin2orange:

Don't mind me just here for the show.

I didn't think about doin a thread like this till after I already machined the cyl :bang:so these pics are a 562xp cyl.

Cuttin the squish band


turning down the base.

Sweet! I love "how to" threads :biggrin:

parrisw said:

Don't mind me just here for the show.

Click to expand...

Hope you got plenty of dollar bills:hmm3grin2orange::hmm3grin2orange:
Poll dancing class is next

Can you show me a pic of your tool?










I mean, your cutter tool.

Stumpys Customs said:

Hope you got plenty of dollar bills:hmm3grin2orange::hmm3grin2orange:
Poll dancing class is next

Click to expand...

Time to break out the Monopoly money!!!!!

parrisw said:

Can you show me a pic of your tool?










I mean, your cutter tool.

Click to expand...

at least buy me lunch first.


I'll be getting to it.

parrisw said:

Time to break out the Monopoly money!!!!!

Click to expand...

Just don't be tryin to stuff the houses & hotels down my thong. The shoe maybe.......

What's that long thing stuck in the bore?

After I get the machining done I install the piston & cyl and set up the degree wheel to start marking out how much I need to take off the ports to get them where I want. I start with the ex, then the upper transfers, and on to the intake. I turn the degree wheel to the number I want then I make a mark on the piston for the intake & exhaust thenmeasure from the edge to the line to give me the amount of material to remove from the port. on the transfers I have to make a mark at where the port is before grinding & then turn the wheel to the desired degree & make another mark. I hope that all makes sence.:msp_confused:

Here's the ex side of the piston with the marks. The top one is how much I need to remove from the roof of the ex port. The middle mark is the Upper transfer mark. It lined up with the top of the second ring groove when the top of the piston was even with the trans port.
The bottom mark is how much of the skirt is below the ex port @ TDC.


The intake side is done the same way as the ex. I set the wheel to the degree I want it at & make a mark on the skirt. The upper mark is just a reference to where top of the intake port is on the piston @ BDC.

mweba said:

What's that long thing stuck in the bore?

Click to expand...

The red thing??

Now I'm ready to lay the cyl out. Are the tools I use for that


Here's the intake side lay'd out. I use the piston as a straight edge for the horizontal marks & the little square for the vertical ones.


On the transfers I use the piston ring for a straight edge on the horizontal marks.




I also use the ring for the top of the ex port


the ex flange just gets a straight edge mark & I eyeball the radius's

For the next step I'll be using these tools, 1/4" die grinder with a 5/16" round nose bur, and a bit of oil to keep the bit lubed from time to time.


I start out on the outside of the ex port to open it up first.



Then I move to the inside of the port


I then move back to the outside to blend it all together. This is what the ex port looks like roughed out.

Thought I'd throw in a pick of my little vise with plastic jaw inserts.


Time to move onto the intake side. I start on it from the inside.


Then on to the outside


All roughed out with the same bur that I used on the ex.


I've learned from experience that you have to be careful with the clutch side on some of the stihls since the port is angled. You can go right through the side where I've got the arrow & line on the base of the boot flange. I've had to weld a couple of holes up before, but it's been a while since I've had to do that. Live & learn.

Excellent clear pictures and a nice job of explaining things.
Thanks