The Husqvarna 550XP

[David Young]

What do you guys use for block offs for a pressure test?

 

[David Young]

Nasty inside. Does this carb boot look like enough to worry about.

 

[huskyboy]

Nasty inside. Does this carb boot look like enough to worry about.

Personal saw I would try and see if it worked, if I was selling it I’d replace it.

 

[radio]

What do you guys use for block offs for a pressure test?

Bicycle inner tube. Cut pieces to size for the muffler and carb and punch holes for the bolts so the rubber fits like a gasket. Then remount the carb and muffler with these new rubber gaskets. Get an adapter to connect your pressure tester in the spark plug hole.

 

[M2theB]

I got this guy a while a ago from a pretty angry owner. It has the compression of a saw without a piston ring.
The fuel tank smells like rotten skunk.
Before I start pulling it apart I brought it to a shop for diagnostics, hand written above.
Looking for advice on the next step. The shop guys were very confident it was bad fuel that did it in. Air leak is not a crazy thought.
I’m looking forward to pulling the jug to see what it looks like.

 

[chipper1]

View attachment 152577 View attachment 152578 View attachment 152579 I got this guy a while a ago from a pretty angry owner. It has the compression of a saw without a piston ring.
The fuel tank smells like rotten skunk.
Before I start pulling it apart I brought it to a shop for diagnostics, hand written above.
Looking for advice on the next step. The shop guys were very confident it was bad fuel that did it in. Air leak is not a crazy thought.
I’m looking forward to pulling the jug to see what it looks like.

Look at the purge bulb, looks nasty to me, one of the reasons I like them, gives me a quick look at the fuel system without opening them up. If the bulb is nasty looking(that one isn't the worst but the fuel doesn't look good) then I'd replace the lines and filter at minimum.
I had a 562 that I believed was scored because of ethanol/fuel separation, I sold it and the new owner put a new piston in and was off to the races. Hopefully that's all you need too.

 

[M2theB]

Look at the purge bulb, looks nasty to me, one of the reasons I like them, gives me a quick look at the fuel system without opening them up. If the bulb is nasty looking(that one isn't the worst but the fuel doesn't look good) then I'd replace the lines and filter at minimum.
I had a 562 that I believed was scored because of ethanol/fuel separation, I sold it and the new owner put a new piston in and was off to the races. Hopefully that's all you need too.

The inside doesn’t look any better.
Found it was missing a circlip. I’d really be PO’d if I was the guy I got it from.
Fuel still smelled rancid.
Not sure if this is a chicken and egg thing, but I’m thinking the circlip was the first domino if not just a cinder block

 

[chipper1]

View attachment 152752 View attachment 152753 View attachment 152754 View attachment 152755

The inside doesn’t look any better.
Found it was missing a circlip. I’d really be PO’d if I was the guy I got it from.
Fuel still smelled rancid.
Not sure if this is a chicken and egg thing, but I’m thinking the circlip was the first domino if not just a cinder block

That stinks, looks a lot worse than the 562 I had . It only had a light smear on the piston, and wasn't ran after the problem was known.

 

[M2theB]

That stinks, looks a lot worse than the 562 I had . It only had a light smear on the piston, and wasn't ran after the problem was known.

Thanks for the feed back
The circlip was actually where it belongs.
Replacement came with one clip already installed which was nice. And the ring was on the piston too.

 

[smokey7]

I would love to get my dad a 550 or 562. I just rear they are not farmer tough enough to survive my dads extra low rakers(rough on bearings) and 50:1 just got him to agree to 40:1 in i premake the bottles for him. So i buy little 8oz plastic bottles online and fill them for him for 2 g gallons of rec fuel. I just got him to start running that aftee he had to rebuild a bunch of his old john deere D's carns and other carbs ob all sorts kf equipment. Hopefully now witg 40:1 with better oil and 90 octane rec gas i should have less stuff to fix for him now. Hell ive seen him try to use mix thats 6 months to 1 year old damit dad.

 

[chipper1]

Thanks for the feed back
The circlip was actually where it belongs.
Replacement came with one clip already installed which was nice. And the ring was on the piston too.

Sounds good.
What was the total fix on it.
I just snagged up a 545 today as well as a 353.

I would love to get my dad a 550 or 562. I just rear they are not farmer tough enough to survive my dads extra low rakers(rough on bearings) and 50:1 just got him to agree to 40:1 in i premake the bottles for him. So i buy little 8oz plastic bottles online and fill them for him for 2 g gallons of rec fuel. I just got him to start running that aftee he had to rebuild a bunch of his old john deere D's carns and other carbs ob all sorts kf equipment. Hopefully now witg 40:1 with better oil and 90 octane rec gas i should have less stuff to fix for him now. Hell ive seen him try to use mix thats 6 months to 1 year old damit dad.

Sounds like you need to get him a stihl 2 in one sharpener. They put a nice edge on and get the rakers set at the same time, and they are a progressive raker depth so he should be pleased with the way it cuts.
What saw does he currently run.

 

[M2theB]

Sounds good.
What was the total fix on it.
I just snagged up a 545 today as well as a 353.

Sounds like you need to get him a stihl 2 in one sharpener. They put a nice edge on and get the rakers set at the same time, and they are a progressive raker depth so he should be pleased with the way it cuts.
What saw does he currently run.

For the 550xp, I went with a bad gas/straight gas failure. I flushed the tank, lines and flooded the carb with Husqvarna XP fuel.
And replaced the p/c.
I’m not convinced it’s 100% right. I’ve been running for a while when I get home to continue to get the good fuel through it and clean out the passsages.
The diagnosis of a code 13 is too long to return to idle. I have a healthy 550xp to compare it too. I don’t think this repaired unit is snapping back like the healthy one. I need to do a side by each comparison

 

[huskyboy]

Probably needs a good carb clean/kit and reset/update.

 

[chipper1]

For the 550xp, I went with a bad gas/straight gas failure. I flushed the tank, lines and flooded the carb with Husqvarna XP fuel.
And replaced the p/c.
I’m not convinced it’s 100% right. I’ve been running for a while when I get home to continue to get the good fuel through it and clean out the passsages.
The diagnosis of a code 13 is too long to return to idle. I have a healthy 550xp to compare it too. I don’t think this repaired unit is snapping back like the healthy one. I need to do a side by each comparison

May not be 100%, but it's hard to tell as they tune themselves back to so close to where they should be many times you don't know there's a problem even when you have a saw to compare it too.
Code 13 seems to happen on many of these that are running just fine, especially when guys run them low on fuel(per dealers I've talked to).
Get it in a nice long cut and let the computer adjust itself even after an update and they will typically run better. Sharp chain in a log cutting length wise is what I use, or a large round up on end and backbar all the way around it so you never have to let off. The chips will fill the cut and you won't have to stop to put a wedge in, nice trick for flush cutting stumps too.

 

[chipper1]

Probably needs a good carb clean/kit

I shouldn't have assumed he did this.

 

[M2theB]

I shouldn't have assumed he did this.

The saw didn’t need an update or reset according to the diagnostics. A good carb cleaning is probably needed. I hit it pretty it good with air and carb cleaner.
For now I’m going to run some Husqvarna XP fuel through it on idle for a while and a periodic goose. Break in on the new p/c and hopefully blow out what the new fuel scavenges for crap.
Tonight it ran better after 3 night of this process. I’ll get it in the woods this weekend for a tuning cut and some cutting.

 

[1990Husky262]

Does anybody have the part numbers for the intake block off plates

 

[M2theB]

I shouldn't have assumed he did this.

The rest of it
I rebuilt the 7A carb and gave it a good cleaning while in there. I adjusted the air by pass a half dozen times ccw from a 1/8th turn to nearly a full turn and I got it to a point I was optimistic. But then I got it in the woods and it had a hard time getting off idle. Actually was dying, quit, stop.
I verified the coil would work with an AT-12 and pulled the trigger on that.
I built it this weekend. Ran a bunch a noodle cuts to tune it. Got it good and warm. Ran great. Took it out in the afternoon and dropped and processed a 14” maple. Ran great. Went back out today to finish the clean up and then walk the edge of the field to zap the bittersweet. Ran great.
1.5 tanks through it with out a bog or stutter.
I hope it’s the final fix. It really runs nice right now.

 

[chipper1]

The rest of it
I rebuilt the 7A carb and gave it a good cleaning while in there. I adjusted the air by pass a half dozen times ccw from a 1/8th turn to nearly a full turn and I got it to a point I was optimistic. But then I got it in the woods and it had a hard time getting off idle. Actually was dying, quit, stop.
I verified the coil would work with an AT-12 and pulled the trigger on that.
I built it this weekend. Ran a bunch a noodle cuts to tune it. Got it good and warm. Ran great. Took it out in the afternoon and dropped and processed a 14” maple. Ran great. Went back out today to finish the clean up and then walk the edge of the field to zap the bittersweet. Ran great.
1.5 tanks through it with out a bog or stutter.
I hope it’s the final fix. It really runs nice right now.

That's great to hear.

 

[Spike60]

Does anybody have the part numbers for the intake block off plates

Exhaust--578 041 801
Carb--574 711 402
Strato Ports-- 578 021 301 (2 required)