Husqvarna 545 mark II

OK, those are max power and max torque rpms and NOT "redline". Again, these saws turn in excess of 14K, no load. The "rev limiter" on chainsaws is done by keeping them properly tuned. Too lean and they will rev too high. Some have limiting coils which limit the rpms regardless of the state of tune. Google how to tune a chainsaw and "4 stroking". Mine are modified and will hold higher rpm's in the cut than they would stock due to intake/exhaust port timing/duration being changed to help increase torque. Increasing torque helps keep the rpm's higher under load (in the cut), resulting in faster chain speed and therefore faster cutting times. With that increased torque both my 346 and 550 have 8 pin (vs 7 stock) sprockets on them to increase chain speed even more.

I have tachs on mine and I know what no-load RPM's I want them tuned to. The 346XP I want to keep tuned to ~14,400. My 390XP to right around that 14K area.

My 550XP is Autotune, so that I can't self tune. Guaranteed it's in excess of 14K.
I bought an 8 pin sprocket for my 390xp. I have not installed it yet.
 
To keep the thread back to the original owner. 545mark ii for longevity. 550mark ii for absoulte bragging rights and peak speed minus just a touch of longevity due to cranks seals and bearings from the crank stuffers.
 
Oh man..... That is going to be a screamer with the 18in. 325 Guage. You will be blown away at the power.

I am shocked the price is so close now in 2026 between the 545 mark 2 and the 550xp mark 2. It's a no brainer now. Back when I got my 545 mark 2 slightly used they were 100 difference.
 
Oh man..... That is going to be a screamer with the 18in. 325 Guage. You will be blown away at the power.

I am shocked the price is so close now in 2026 between the 545 mark 2 and the 550xp mark 2. It's a no brainer now. Back when I got my 545 mark 2 slightly used they were 100 difference.


$50 difference now.
We will see about the power.
I do have a husky 390xp. So I am used to a strong running saw. I need to order an unlimited coil for the 390xp it so I can properly tune the carb.

Looking at ported mufflers for both saws.
 
Going mix some 32:1 to break it in tomorrow.

I think i have an LGX full chisel chain on the shelf, if so that will go on it.
 
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Saw runs great. It starts really easy. Pulls a full house chain no problem.

First tank is 32:1. Cranked it and let it run a couple of minutes then shut it off to let the heat soak in for 5 minutes. Cranked it up and started cutting, loading it up.

It's way more powerful than the echo cs-450 it replaces. Not quite as fast as the 390xp, but its going to be great as the mid size saw for my use!
 
Your quote "Not quite as fast as the 390xp, but its going to be great as the mid size saw for my use!

I got to thinking.........your 550XP should literally scream with an 18" bar x .325 in comparison to how your 390XP feels with a 32" x 3/8.

Was wondering if your 550XP is running this type of raker below? This makes it cut slow and I have had to set these very low and flat to get equiv performance out of them.

1768421462735.webp
 
IMG_20260117_113320649.webp

Your quote "Not quite as fast as the 390xp, but its going to be great as the mid size saw for my use!

I got to thinking.........your 550XP should literally scream with an 18" bar x .325 in comparison to how your 390XP feels with a 32" x 3/8.

Was wondering if your 550XP is running this type of raker below? This makes it cut slow and I have had to set these very low and flat to get equiv performance out of them.

View attachment 319749

No I usually run LGX full chisel chain.
I think the difference is the 390 has the horsepower to pull the full chisel chain, with the rakers filed down for more bite.

Here are some pics. The 390 chain is going in to the shop to be machine sharpened as it hit a nail some where , too much to bother filing by hand.

550xp chain;
IMG_20260117_113320649.webp


390 chain damaged, rakers filed;
IMG_20260117_113731910.webp

IMG_20260117_113753757.webp
 
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Wow...you ain't kidding that chain took a hit. Good news is, if they sharpen it right and open up the gullet as buckin Billy Ray calls it, that chain will cut awsome.

In terms of the 390xp and 550xp, we both have the opposite issue I think...... My 390xp only has 1.5 gal of fuel thru it, so it is most likely slow, my 545 is broke in fully and is a screamer. On the flipside your 390xp is most likely fully broke in and properly adjusted so it is the screamer, and your 550xp is still tight and new.

Your LGX chain looks almost identical to my new EXL except the laser markings on the cutters. My EXL chains for sure need the rakers lowered slightly.
 
Wow...you ain't kidding that chain took a hit. Good news is, if they sharpen it right and open up the gullet as buckin Billy Ray calls it, that chain will cut awsome.

In terms of the 390xp and 550xp, we both have the opposite issue I think...... My 390xp only has 1.5 gal of fuel thru it, so it is most likely slow, my 545 is broke in fully and is a screamer. On the flipside your 390xp is most likely fully broke in and properly adjusted so it is the screamer, and your 550xp is still tight and new.

Your LGX chain looks almost identical to my new EXL except the laser markings on the cutters. My EXL chains for sure need the rakers lowered slightly.
The Husqvarna 390xp is rated at 6.5 hp. The Husqvarna 550xp is rated at 4hp.
Both are powerful, but 2.5 hp is hard to overcome.
If I put the 20 inch bar on the Husqvarna 390xp it really rips.
I'll see what the 8 pin sprocket does. Probably won't change it until I swap chains.
 
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