How do you measure a saws bore without taking the piston out

[Stihl 041 super]

How do you measure a saws bore without taking the piston out? Also the saw doesnot have a head ontop of the cylinder.

 

[fishhuntcutwood]

The only way I'd rely on measuring a bore accurately is to take it off and use a micrometer. And the piston wouldn't give you and accurate measure of the cylinder's bore-you'd need to measure the bore itself, so the piston can stay attached to the saw. Just pull jug off. Four bolts amigo. 7 ft lbs, or just good and tight puttin' back on.

And were you looking for a head on top of the cylinder? Your bio says that you're a small engine mechanic as your occupation. Are you new to saws?

Jeff

 

[timberwolf]

Another way to get close is to use calipers, take the muffler off, use the depth gauge on the end of the calipers.

Put the piston to bdc check the distance from the face of the exaust port muffler side to the back of the cylinder (farthet point in the middle), then move the piston to tdc and measure the distance between the the same point and the piston face (closest point).

The diference between the two is bore diamiter +- some error.

Or even faster, take a piece of fine diameter soft solder, straighten it, put it in the center of the exaust port and push it to the back wall of the cylinder, move the piston up and shear it off, back the piston off and drop the piece out, chech the length with calipers or a ruler. it should get you to the down to the mm anyway.

 

[fishhuntcutwood]

Or even faster, take a piece of fine diameter soft solder, straighten it, put it in the center of the exaust port and push it to the back wall of the cylinder, move the piston up and shear it off, back the piston off and drop the piece out, chech the length with calipers or a ruler. it should get you to the down to the mm anyway.

That's a good idea, and a good point about getting the mm measurement.

Jeff