Husqvarna 450 Rancher carb help needed

[zwoehr]

Hello everyone, I'm a new member with a problem Husqvarna 45o. I recently bought a refurbished 45o "Rancher" with a 20" bar. My problem is that it seems to have no power, it limbs well but bogs quickly when trying to cut anything bigger than about 6". My first thought is that it has an air leak. But my second thought is that the 20" bar is too much for the saw. It starts and idles fine and revs OK (it seems to have a rev limiter it's really hard fro me to tell if it's four stroking. Even adjusted all the way lean it sounds like it is)

To make a long story short I'm looking for advice on initial carb setup and any common problems with these saws. Also wondering if I should bother buying a 16" bar and chains for it or if I should just sell it. I'd like to at least know that it is running right before I pawn it off on a new owner though.

PS my other saw is a 562XP so if I do get rid of the 450 I'm taking suggestions for a second smaller lighter loaner saw. Right now I feel like I should have kept my MS290 and never bothered with the Husky.

Thanks reading and any help.

 

[Landmark]

Hello everyone, I'm a new member with a problem Husqvarna 45o. I recently bought a refurbished 45o "Rancher" with a 20" bar. My problem is that it seems to have no power, it limbs well but bogs quickly when trying to cut anything bigger than about 6". My first thought is that it has an air leak. But my second thought is that the 20" bar is too much for the saw. It starts and idles fine and revs OK (it seems to have a rev limiter it's really hard fro me to tell if it's four stroking. Even adjusted all the way lean it sounds like it is)

To make a long story short I'm looking for advice on initial carb setup and any common problems with these saws. Also wondering if I should bother buying a 16" bar and chains for it or if I should just sell it. I'd like to at least know that it is running right before I pawn it off on a new owner though.

PS my other saw is a 562XP so if I do get rid of the 450 I'm taking suggestions for a second smaller lighter loaner saw. Right now I feel like I should have kept my MS290 and never bothered with the Husky.

Thanks reading and any help.

Would def try resetting carb and starting again. It should cut fine with 20 bar or at least fine for what a 450 will do. I wouldnt sink money in new bar and chain. Tune carb and possible rebuild. If that doesnt fix it cut loss and sell.
A good small saw is 346xp. Good luck

 

[cus_deluxe]

compression check? how many hours since purchasing the refurb? air leak would cause it to scream and idle high generally. what color is ignition coil(i think blue is rev limited, black is unlimited correct if im wrong??) by most accounts 450 is a good and reliable saw. check the easy stuff before throwing in the towel on the orange.

 

[HuskStihl]

Ya something's wrong. I have an old 445 which has no problem with 12" wood. Could be lack of gas, but if it revs and runs well, I'd be concerned about a scored piston

 

[Terry Syd]

The coil is rev limited to 13,000 rpm. The 450 is a bored out 445, as HuskStihl mentioned, the 445 works well in 12" wood, so something is amiss.

I went crazy modding my 450 and turned it into a screaming little powerhouse, I forget how light and strong it is until I pick it up to do some work. It was my only saw for a couple of years and did everything, often times with the 18" bar buried in Ozzie hardwood. It is presently using a 15" NK bar with an 8-pin. I run the Narrow Kerf bar and chain and it makes a nice lightweight saw with the 10.8 lb powerhead. A 2o" NK bar would be about as much as you would want to run on a stock 450. If you're running standard .325 or 3/8s, then IMO you have too much bar on the saw, at least for the wood in my area.

As I recall the stock settings on the carb were 1 1/2 out on each screw.

 

[LegDeLimber]

I'm assuming folks are referring to a 450 rancher here.
Terry Syd, *If* and when I get back to fiddling with stuff, I'd be grateful to pester you about the 450 tweaks. Swapping for unlimited coil would be my first thing to pursue.
Then it's air and fuel delivery time.
Those mini drills and pin vices I posted about in the 7900 carb thread were intended to meet up with my 450, when I'm feeling froggy again!

 

[Terry Syd]

The limited coil on the modded 450 isn't a problem, unless my chain starts getting dull. Then it works like an audible 'dull chain indicator' to let me know to swap chains. It likes to cut in the 10,000 - 12,500 range, so there isn't much leeway to keeping it off the limiter.

I wrote up the mods I did in another thread. Like I said I went crazy, I had to completely rebuild the transfer tunnels to get the engine to breath. I also put on a bigger carb, so with the strato butterfly open, the engine thinks it has a 19mm carb. Way too much work, but I was learning about modding chainsaws - and at that time the general consensus was you couldn't modify 'stratos' - how times have changed.

The carb I used was for a 570. I never measured it, but I expect the low speed jet is bigger than on the stock carb. The engine has lots of low end torque for being such a fast cutting little thing.

 

[LegDeLimber]

Been a while but Seems like that may have been some of my first readings of your efforts.
As for the limited coil, ahhh, I'm just stubborn about wanting to beable to find that portion of the fuel to air curve that's on the graph you posted somewhere a while back.
I'm pretty firm in thinking that "tunning to the tach" number only, is good way to leave the mix overly rich. Stock saws are one thing , but once we alter something, that's a bit misguided I feel.
( insert routine debate about too lean screamers and not being able to tell the diference, etc..)
Tunning by ear and and "4-stroking" still applies, in my estimation.

Now pardon me for posting a bit contrary thoughts and bailing, But I gotta go get ready for a two separate Doctors day today. fun fun fun!

 

[Terry Syd]

I'm pretty firm in thinking that "tunning to the tach" number only, is good way to leave the mix overly rich. Stock saws are one thing , but once we alter something, that's a bit misguided I feel.
( insert routine debate about too lean screamers and not being able to tell the diference, etc..)
Tunning by ear and and "4-stroking" still applies, in my estimation.

I have a tach mounted on the saw. I tune in the wood using the tach. Maybe some people can pick up a 200 rpm increase at 10,000 rpm, but that is only 2% difference and I can't hear it.

 

[zwoehr]

Thanks for all the replys. The saw has a black coil with a blue wire. From what I can see from the exhaust port the piston and bore look fine (looks like the cylinder is not removable? The spark arrestor had soot around it, but I didn't pull the spark plug yet. I'll try setting everything at 1 1/2 turns out and starting over with the tuning.

 

[cus_deluxe]

cylinder bolts probably come in from the bottom.

 

[zwoehr]

I just reset the adjustment screws to 1 1/2 out from closed and retuned it. It works great now! I Ended up around 1 to 1 1/4 on the L screw and about the same on the H screw. It's around 55-60 degrees here at sea level with high humidity. I think I will probably keep the saw now. It is light and it cuts pretty well. Thanks for the tips everyone. I still would like to try a 16 inch bar and chain on it though. Any recommendations for lightest/best balue?

Terry Syd, do you have a link the mods you did to your 450? I searched but didn't find it.

On a different subject, does anyone know the difference between the Husky Rancher and non Rancher models. The only thing I could find in the specs was half a pound heavier for the Rancher model.

 

[Terry Syd]

You might want to try a Narrow Kerf bar on the saw. It will be lighter and cut faster. The side links and cutters are only 1mm thick versus 1.25mm thick for the standard .325, but the chain is just as strong as a standard .325 chain (they pull apart at the rivet hole in the drive links and the drive links is the same for both chains). Not only does the reduced width of the cutter reduce the width of the cut in the wood, but it is easier for the thinner cutter to enter the wood. It is worth about 15% or so in cutting speed at the same time it makes the saw lighter.

Here's a link to that old thread, there is a lot of blather in the thread as I worked through the mods and tried to find what worked and what didn't - http://www.arboristsite.com/community/threads/help-building-tuning-a-strato-husqvarna-445.107976/

 

[Fishmax2]

my rancher 450 has a 24" bar and have cut logs up to 30" in diameter. Serious problem with yours.

 

[zwoehr]

my rancher 450 has a 24" bar and have cut logs up to 30" in diameter. Serious problem with yours.

This is from a year ago. I got the carb adjusted and used the saw for a while then sold it. I thought it was funny that a saw that the manufacturer did not want users to tune needed so much adjustment to get it to work right.
You have a very powerful 450.

Sent from my VS985 4G using Tapatalk

 

[Fishmax2]

Guess so, I have been really happy with mine