ms 260 pro muffler mod

[timberrat]

is it safe to open up the muffler outlet hole by 3mm

 

[computeruser]

Yup, I should think so. That's not a huge increase in exit hole size.

 

[Lakeside53]

Take out the screen, drill two 5/16 th holes, one above and one below the existing hole (from the inside), remove all metal particles and burrs, put the screen back in and you are done.

 

[Kneejerk Bombas]

It depends if you can open up your high speed jet to compensate.

 

[mrk585]

High speed jet

How can I open it up I don tknow to much about saw carbs I work on cars not saws

 

[Lakeside53]

First you have to remove the limiter cap on the H screw jet. There is a special (but cheap) tool to do this, or, have your dealer pull it. If you use a screw you will likely mess up the cap and have one heck of a job getting it out. A new cap cost 50c and you need to put one back (slice off the limiting tab first). Note that the L screw on your carb has no limiter cap and a spring holds it in place; the H just has the cap and no screw).


Once your cap is out, turn the screw out about 1 1/8 turn from gently seated and do you tuning from there.

Do a search on AS - this has been discussed many times and you'll get few views and tuning details.

 

[drunkenredneck]

3mm wont hurt the saw as long as you retune it like others have said. I personally would pull the muffler and match it and the gasket to the exhaust port as well. But by the sounds of it you just want to tinker a little. I would reccomend haveing someone retune it for you but show you how to do it as there doing it so you'll get that skill.

 

[timberwolf]

You will have no problems going to three 3/8 holes and joining then together.

On a modified saw with high flow filter, I found gains upto 0.6 in2.

It will require a carb adjustment, don't skip that part. Also it is importaint to debur and wash the parts so no metal filings can make it back into the engine.