Top 10 Husqvarna , No.455 Rancher, 20" Gas - Powered Chainsaw Questions & Answers

hello sir, chainsaw carb.settings,try adjusting carb this may help, first remove the air filter housing and air filter,turn both screws in all the way, now turn both screws out 1 1/2 turns, if saw is hard to start i use carb cleaner to spray in carb it makes it easer,once you get saw warmed up,start adjusting the high side first a little at a time,than the low side, it is quite hard to adjust when saw is running at top speed,that is why i let saw idle while making adjustments than try again.keep doing this untail it sounds ok low & top speed. now you will have to rejust the top speed when you cut wood to get it right. a clean air filter and a new spark plug would help also. if you still have this same problem than your carb has a fuel restriction,most likely caused by the screen inside the carb.if you take the carb,off make note where the fuel lines go.hope this helps,MrFixIt, oh could you please rate this solution,thank you..

It depends on the chain you have installed on the chainsaw. You can look at the numbers stamped on the drive link side of the cutting chain and it should have a 2 digit number that correlates to the size.

The factory chain supplied with the #455 rancher was a .325" pitch 3/8" chain.

Here's a link to the specs for your saw with some useful info

http://www.husqvarna.com/us/homeowner/products/sawing/chainsaws/455-rancher/#specifications

Hope you found this very helpful and best regards!

Check the air filter and the muffler if either are plugged up it will not run smooth. Carb hi and low screws are very sensitive so if you change them, only move them a little at a time.

Start with "H" and "L" 1 turn CCW from lightly seated. Then tune for performance like this.
Carburetor Adjustment by Madsens.com
http://www.madsens1.com/saw%20carb%20tune.htm
CW is leaner; to lean will destroy the saw. If over tightened closed (CW) the adjustment screw faces are easily marred; marred adjustments are difficult to impossible to set properly.
Clean the air filter; adjusting with a dirty filter can cause a run lean condition once cleaned and the saw run.
There are 2 wav (sound - idle & full – may not be highlighted) files that I find most helpful, I think you will too. HTH
Lou

Try blocking the throttle arm on the carburetor in the wide-open position with a small stick, then deal with the trigger mechanism. In order to remove the cable from the carburetor, you need to remove the carburetor itself, then unhook the cable end at the throttle arm. Keep track of which fuel hose goes where if you do this. Hope this helps!

hi

check the fuel filter,clean the gas tank,the carburator ,check the fuel pump(not to be tired).the fine filter inside the carb under the fuel pumpand the sparkplug.

by for now savumihai71

Make sure the chain break is releasing all the way. When the saw is not running release the chain break and make sure you can move the chain back and forth by hand. If you can there is a small fuel filter in the gas tank that should be replaced. Make sure the fuel lines are not spongy because they could collasp when the engine is running starving the carburetor for fuel.

Hi
Make sure you are getting spark at the spark plug, to do this:
Remove your spark plug and check to be sure you are getting a bright blue spark at the spark plug.
You do this by grounding the plug on the head of the engine and pulling the crank rope while you are watching the plug for spark.
If you are getting a nice blue spark then skip A below and go to B.
A...If you do not get a nice blue spark then you may need to replace the electronic module and or the sparkplug.
Note: If you have to replace the module be sure to measure the position it is in, it is critical to starting.
B...Also take some fine grit sandpaper (not emery) and lightly sand the flywheel where the magnet is located to clean any rust or corrosion from the magnet area.
Then follow the procedure below:
******************************************************************************************************************
Sounds like you have dirt/debris in your caburetor jets,fuel passages or a diaphgram that is becoming non-flexible.
Check/Clean/Replace your Air Filter, a dirty air filter can make your engine run to rich with fuel.
Note: ALWAYS USE COMPRESSED AIR TO CLEAN YOUR JETS AND PASSAGES, VERY IMPORTANT.
Note:Before you disassemble the carburetor:
Write down on a piece of paper or take a picture of how the linkage attaches to your carburetor for later reference when you go to reinstall your carburetor.
Mark each piece with a awl, or some kind of instrument that will make an alignment scratch before you disassemble the carburetor into separate pieces.
That way you will know which way it goes back together when you reassemble it.
Sometimes you can get by with priming the carburetor or by using starting fluid and letting it run a few times like that, and it will flush the gunk out of the jets,but most of the time you will need to rebuild the carburetor.
Be sure to check your fuel tank for water and dirt/debris, if there is water/debris then you need to clean your tank.
Check you fuel line condition after a while they will degrade and need replacment.
Check/Clean/Replace your fuel filter if you have one, normally they are located in the fuel tank of chainsaws and weedeaters.
When you remove your fuel lines from the carburetor be sure to make a drawing to how the lines are connected to the carburetor or take a pictue for later
reference.
Normally the big line will be the line the fuel filter is connected to inside of the tank.The smaller of the two lines is the return to the fuel tank from the carburetor after it is pumped thru the carburetor by the primer bulb.
Make sure you are using fresh fuel...and oil mix if your using a two cycle chainsaw or weedeater with the oil to the right mixture and not too much oil as it can cause hard starting.
If the mower/trimmer is over a couple of years old, then I recommend that you buy and install a new carburetor repair kit,because the diaphragm will get hard and that will cause it to be hard to crank.
The diaphgram may look good and flexible, but it can be deceiving and not act as a fuel pump as it should because it has become too hard and will cause hard starting,start and run and shut off, etc.
When you clean your carburetor, I recommend that you use a laquer thinner type cleaner to clean and dissolve the laquer build-up in the float and needle jet passages.
Be sure to remove all plastic and rubber parts before using the laquer thinner because it can dissolve the plastic parts and render them unuseable.
Be sure to use COMPRESSED AIR to blow out all the fuel and air passages.The higher air pressure is needed to blow some of the trash/debris from the fuel or air passages.
Be careful when blowing out the passages, because there are sometimes small rubber type seats in the bottom of some of the passages.
Keep in mind that the float (if you have one) for the carburetor must be level when you go to reassemble the carburetor or follow the instructions you get with the carburetor kit, or you could also ask the parts man that you get your kit from.
When you clean your carburetor and remove the jet screws, you will first need to lightly seat the jet screws.
But before you lightly seat the jet screws count the number of turns it takes to seat the jet screws from their original position.
Be sure to mark the turns down on a piece of paper.
That way when you put the jets back in, you know to lightly seat them first and then turn them back out to their original position before you started.
Note:
The little spring inside of the carburetor goes under the float arm.
That is where your fuel inlet needle/float valve is located...on the arm at the end.
Normally there is a small indetion in the carburetor base and a small protrusion on the underneath of the float arm where the spring will be in the right postion for installation.
The spring will set in the indention and you will install the float arm with the needle/float valve and float rod into position over top of the spring,you will push down until it is in position and then you can tighten the screw that holds the float arm assembly in position.
Once you have your carburetor cleaned/rebuilt that should solve your problem.
Please take time to rate me thumbs up

The tank vent has been an issue, it can not only vacume the tank it can pressurise the tank and cause flooding, the breather is under the starter cover on the top right hand of the tank, i have replaced the original breather to the early 357xp breather, this is like a small white pellet of vion ( a breathable plastic )

you need too adjust the high jet ccw (making it richer) do do that takes
a little work cause you need a special tool but I can help you around that if you like. let me know