DIY 357xp mods.

Well,right or wrong,I did my own "muffler mod" yesterday by boring a 1/2" hole out of my non-etech muffler via the front muffler support.Other than making it louder, it seems to have opened the saw up a bit-ran 2 tanks through it today,it seems a little quicker in the cut than before.My question:is there anything I should be wary of?Are there any specific carb. adjustments I oughta make now or certain gas\oil mixes I should run?It appears to be running as reliably as ever-I just don't want to do any real harm to the engine if possible.The 357 is my only saw right now;'til I figure out why the old 028 super won't start.(a hard lesson learned from lending out your saw!)Any tips or advice on the proper diy mods would be greatly appreciated-Thanks.

YES! Carb adjustments are absolutely necessary, otherwise your saw will be very short lived. You need to remove the limiters and richen the 'H' screw to bring the RPMs back down to spec.
Ian

Thanks for the tip Haywire,how exactly do I access the limiters?Please bear with me-I'm no saw whiz, but a competent handyman.

If you look at the carb screws, you should see what looks like a plastic cap of sorts with "wings" that limit the travel of the screw. You can either remove these caps completely or trim off the "wings" with a sharp knife so you can adjust the carb beyond the factory limits.

Some carbs depend on these limiters to keep the adjustment screws from backing out. I don't know if yours is one of these. I'm sure someone with better knowledge will show up shortly. I wouldn't be surprised if you saw more power gain once you adjust them.

Ian

Good info:I'm gonna mark the carb screws position as they are now, then find the limiters and adjust the "h" screw as necessary.Thanks again.

I'm not trying to be a jerk here, but for the sake of other, you MUST retune your carb after a muffler mod. Not after a couple tanks either. That's more than enough to either damage or burn up a saw if it's lean enough. Most saws seem to be on the lean side already from the factory. To go and make them even leaner is a recipe for disaster. Now after saying all that , Saucydog, you're saw will more than likely be fine. Retune that carb and enjoy. I will note that a correct tune on a muffler modded saw may not yield the same RPMs as a stock saw. It may want to run more RPMs now. You'll have to tune it by ear initially and then fine tune it in the cut. Whatever setting yields you the fastest cut times is where you want to be.

I rebuilt my 359 and added a muffler mod with carb adjustment she runs stronger and louder. 357 and 359 are brothers, almost identical. You'll need a propane torch a needlnose pliars and a utility knife with a new blade.
Take off the air filter cover, locate the high and low screws, you will see that they are recessed in what appears to be a black plastic figure 8 lying on its side. this makes it hard to get at the wings on the sides of the mixture screws. It has to go. Set up the propane torch a few feet away so you won't get burned or tip the torch over or light the fuel in the saw up. Heat up the utility knife blade and quickly split the plastic figure 8 by melting/cutting it in 1/2. use the hot blade to sever it from the carb and pull it out with pliars. Now you will be able to see the red and white limiter caps. make note of ther positions and rotate them till you have access to the wing on each one, use the heated blade to shave off the wings and they will be able to rotate 360'. Rich up the low 1/8 turn, and the high 1/2 turn. start it up and make a few cuts. When your cutting and take pressure off the bar during the cut keeping the saw wide open you should herer the engine warble as its reving. Thats the sweet spot. Remember better rich and slower that lean and seized. corey:greenchainsaw: