550XP Auto Tune Diagnostic Reults

glad its going for you
when i said to pull coil it was because of the coil pulling on flywheel and making it act like it wasnt right inside

 

That was it! They’re pretty strong. Never experienced that before

 

ive rebuilt about 75 saws so far and seen almost everything but the information i gave you came from tree monkey a couple summers ago at kevins gtg
he is a wealth of knowledge

 

That was one of the fun parts about rebuilding this saw, learning that!

In the video the saw is still a little dodgy. The chain got real tight and it had only been running for a few minutes. It actually died on me in idle and wouldn’t start normally. I use a lot of 2 stroke for lube putting them back together so started it WOT like it was flooded. Babied it a bit and made some tuning cuts and then let it idle for 10 minutes and the. A few more tuning cuts.
Right now it’s nice. Starts on first pull, snaps back when goosed and marches right down to nice idle.

Re assembly is like a rubics cube.

Thanks for the help today!

 

You too. Thanks for the help today!
Mike

 

i dont like what the epa says and requirements for saws run a good oil and atleast 40:1 and the bottom end will stay lubed
ive taken saws apart that was ran 50:1 their whole life and the bottom end will be dry

 

Some follow up.
I found that the dodgy ness out of the block wouldn’t go away. In fact, the hotter the saw got, the worse it got. To the point that after a tuning cut I could goose the throttle and stall the machine.
I did some research and found that some 2015 550xp and earlier can suffer from “Off Idle Bog”. A lot the post I found had the saw owners bringing them back to the dealer under warranty with no solution provided. Some posts said the metering diaphragm stretched under temperature and that replacing that could be a fix. The most common though was adjusting this air by pass jet nestled under the brass Welch plug. I think it’s possible that adjustment might be necessary because of the stretched diaphragm.
I decided to turn the screw. 1/4 turn CCW. Took it for a test run and low and behold, it was much better. But not great. So I went back in and went about another 1/4 turn CCW.
Now it is much better! If I wasn’t looking and listening for it, I don’t know if I would even no the difference.

 

And following up.
After the last post I ran it more and the there still was a bog.
Following a thread on another site I:
Plugged the decomp, no change,
I trimmed a couple coils off the metering spring, worse, but my fault.
I ordered a carb rebuild kit, K1-AT Walbro, and a new metering spring ( this kit doesn’t come with a spring, need to order that separate)
And the kit comes with an alternate pump gasket set.
Today I rebuilt the carb, after setting the bleed screw back to the original spot.
Bogged badly!
So went back the bleed screw: 1/4, then 1/2 and finally near one full turn ccw. This is a AT-7A carburetor.

So far, I’m much more encouraged with the results.

 

This is after a good idle and a dozen or so noodle cuts

 

Back to the bench.
I took this one out back to work on some dead fall and it ran like crap off idle.
It was probably 20F colder than when it ran well in the pile, but I expect it to accommodate the delta.
I’m eyeing a new AT-12 and maybe a new coil.
This coil does have a funky little blemish I hadn’t seen before.
More to come.

 

I was able verify the coil would match with an AT-12, so I pulled the trigger. Got it configured for the coil, so it ready to throw in.
Looks the same as the 7A but the fuel nipple points down. And it come with a fuel line I didn’t ask for with some instructions to cut an inch off. I bet I need both.

 

Where did you purchase? Price? Lastly, how did you determine the coil would match?

 

Rodd Simonian,
Without giving the exact price, less the $130 delivered.
Rodd checked the coil number with Huski tech to confirm it and used the same data to set the program

 

I used to watch some of his videos on the yootoub.

 

Are you having the same issue with a 550?

 

Mike, does your 562 act similar?

 

I have experienced off idle bog. Usually when it's hot (above 80*) outside.

Can you please confirm Husqvarna part number for carb?

 

It does NOT

 

So for the fuel line and the instructions, it was confusing at first.
What it’s saying is if you have a fuel line whose part number is 573 99 35 03, you’ll want to cut an inch off of it because fuel nipple on the AT-12 point down. Otherwise, change out the fuel line with the shorter version.

You can see, side by each the difference in length.

Don’t cut the short one if that’s what you have.