Project Stumpbroke How I do it

[wendell]

you dirty old man you

I despise every post you make because on every post, the girl in your avatar still hasn't moved her arm. :msp_angry:

 

[Stihlofadeal64]

I despise every post you make because on every post, the girl in your avatar still hasn't moved her arm. :msp_angry:

while I've never been accused of being "politically correct" that's got to be the "homeliest" girl I've ever seen. Pardon me for being too frank...:msp_scared:

 

[Stumpys Customs]

Now that I've got the ports roughed out & they are where I want them i bevel the edge of the ports with this critter. It's just a stone that I've profiled to have a bevel on both sides.

Ex port bevel

Trans bevel

On the intake I just barely bevel the top edge since the ring does peak out when it's @BDC.
The rest of the intake doesn't really need a whole lot of beveling since all it does is seal up against the skirt.

 

[WKEND LUMBERJAK]

This thread rocks

 

[Stumpys Customs]

Once I get all the ports beveled the way I want I move on to the finish work on the intake & exhaust ports. For that I use a drill & a piece of sandpaper wrapped around a piece of chain file.

I start out with 220 on the IN & EX ports. Then I continue wit 400 & 800 on the ex port to get it nice & smooth. While I'm sanding I spray some WD40 on it to keep the paper from loading up.

Ex after 220 grit

Finished with 800 grit

 

[Stumpys Customs]

Now the cyl is done except for a final trip through the ultra sonic cleaner. Time to move on to the piston. I don't do a bunch to the windowed pistons just open up the windows & profile the bars to help flow. It also lightens it up a bit. This Meteor piston started out 5 grams heavier than the stock one. I weighed both of them with the pins since the Meteor pin is heavier also. I removed enough material to get it to the same weight as the OEM 93 grams with pin.

 

[Adirondackstihl]

Whats used to clean the flash from the piston and clean the windows?
My hat is off to ya......:cowboy:

 

[wendell]

Whats used to clean the flash from the piston and clean the windows?
My hat is off to ya......:cowboy:

I believe he said he tosses it in the USC.

 

[Jwalker1911]

Pretty cool thread Stump

 

[garyischofield]

very impressive

Impressive work,impressive thread.I appreciate the effort to show us your work.

 

[Stumpys Customs]

I almost forgot to add one of the most important parts of a build. Making sure the piston will fit in the hole.:hmm3grin2orange:
I've got a dial bore gauge that I use to check the diameter of the bore and I use an outside micrometer to check the dia of the piston skirt. I like to have around .002" skirt clearance. I also measure the piston just above the top ring and I look for .008"-.010" there.

I also check the ring end gap. These are @.010"

I slide the ring down in the bore just about half way between the top & the ex port to take my measurement.

 

[Stumpys Customs]

Another thing I usually do to a saw is advance the timing a bit. This saw has a removable key that I clamp in a pair of vise grips & use a cutoff wheel to remove about half of the key that stick up above the crank. This gets me +10* over stock timing which seems to help.

 

[Stumpys Customs]

Whats used to clean the flash from the piston and clean the windows?
My hat is off to ya......:cowboy:

I use a small double cut tree burr for the pistons.

 

[Stumpys Customs]

Last but not least is the muffler. Unfortunately I don't make shrouds for most of the Stihls. I open up the existing outlet (if you wanna call it that). awfully small hole to breath out of.:bang:

A before pic of the baffle.

Here I've cut away most of the baffle & port matching it to the ex port.

I open the side up as far as I can & also open up the hole that holds the screen.

 

[Stumpys Customs]

And when I put all that together I get something like this.
[video=youtube_share;tn1fu_fduqo]http://youtu.be/tn1fu_fduqo[/video]

 

[DavdH]

Alls' I need now is a chicken coop and several hundred dollars worth of tools I don't have a clue about and I can make you rich fixxin' my mistakes, on second thought maybe I'll just let you do then to start with. Great info, interesting but you are safe from me ever trying to compete, not much consolation I know, great info thanks.

 

[Nardoo]

Great stuff sir, it is a pleasure to see an artist talk about his work! And rep sent.

Al.

 

[splitpost]

outstanding thread ,thanks for sharing

 

[benp]

outstanding thread ,thanks for sharing

I agree 150%

Thank you for sharing this Stumpy!!!!

 

[garyischofield]

don't judge a book

Stumpy,I see you in a different light.What's next for you a beret and ear surgery?I think that snipe by Randy was most unfortunate,"Strumpet?":msp_wink: