1st port job - MS460

[JeremyFXDWG]

I have an MS460 with about 10 hours on it that I want to do a mild port job on. The saw currently has 175lbs of compression and .032 squish. I have not measured port timings as I don't plan to change any of that as it is my first port job. I still have the jug bolted to the saw till I get some advise here.

My Plan:

1 - Widen the intake and exhaust port to within .03" of the piston skirt or 65%-70% of the boar width (do you measure this along the cylinder wall or "strait" across the boar).

2- Clean up and open up the windows on the piston

3- taper the lower transfers to the base of the cylinder

4- Remove base gasket to attain .02"+ squish. (will I be to low starting with .032" squish)

5- port match muffler / gasket / heatshield

6- open up my duel port cover to 125%-150% of the area of the exhaust port at the cylinder wall

7 - should I taper the upper transfers back toward the intake???

I just want this to be a real strong work saw it will mostly have a 25 or 20 inch bar on it. Sometimes it will have a 28 but I am currently looking for a 660 that the 28 will end up on.

THANKS!!
Jeremy

 

[mdavlee]

It sounds like a good plan. I tore a 372xpw and 390xp apart with less than 5 tanks in both of them. It is a good learning experience. Grind a little measure, grind more, measure. Just take your time. You might have to make a gasket out of something to get the squish just right.

 

[JeremyFXDWG]

Good God man leave that new 460 alone except for the duel port muffler cover and shaving the high needle stops.



Start on something less valuable.

I hear ya though my next saw will be a 660...