Echo 620p muffler mod and tuning

[Austin Cantillon]

Hey I just bought a 620 and it's pretty much perfectly tuned right out of the box 4 strokes out of the cut 2 strokes in obviously I'm guessing it might change as it gets broken in but if it doesn't change to far my question is is it even worth pulling the limiters when opening the muffler mod would it throw the tune off that much pr should I try it first and see how it responds?

 

[EchovsStihl63]

Me personally I would want to set the tune myself as I do not trust how it is set from the factory. My 620 that I just bought was pretty lean on the L side of things. It would struggle to idle at times especially when it was cold and was really boggy when hitting the throttle from a stand still. Clipping the tabs off of the adjusters and re tuning it really made a difference in how it starts, runs and idles. It is pretty hard to get these too lean on the H side from what I understand as they have the bypass jet on the high side, but I was able to set mine yesterday how I always do, which is set it so rich that it 4 strokes in the wood and then dial it back a little at a time to where it just cleans up as soon as it is in the wood.

Any time you increase exhaust or intake flow you are going to be changing the tune of the saw, for max gain of your mods and the longevity of the saw I would recommend retuning when you do the mod. I am going to put the red beard air filter on mine as it is already trying to suck fines in by the intake tube after 2 tanks of fuel, so after I do that and get about 8-10 tanks through it I am going to pop the muffler off and open it up a bit.

 

[EchovsStihl63]

Also if you do not want to cut the tabs on the limiters, you can pop the caps out, set the H/L where you want, and then just simply put them back over the screws when you re done. I am sure that is how the dealer does it.

 

[Cliff R]

I wouldn't even test a saw with limiter caps installed as I want to make sure it has PLENTY of fuel to it over the entire load/speed range. The CS-620P's are closer than most others right out of the box, but there are still a LOT of variables in the equation which make custom tuning a LOT better option that leaving it the way Echo set it up to please the EPA.......FWIW......