576xp air leak?

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Uneven case deck? Check it. Mismatched case halves have caused me issues.

I wish it were that simple but they were even.

The funny thing with this saw is it runs the same nomatter what i do to it.

Its been a fun and annoying project.
 
I had a 576 straight from Sweden that was even till it got warm, it was maddening. The smart guys at husky finally figured it out. Expansion.

Ran perfect until it was fully warm. Took about 10 minutes.
 
I had a 576 straight from Sweden that was even till it got warm, it was maddening. The smart guys at husky finally figured it out. Expansion.

Ran perfect until it was fully warm. Took about 10 minutes.

That is my saw to a T!!!

Hmmmmmmm now you got me thinking.

It runs perfect for about 10 mins then it leans out..

Its been that way with both cases though, I also installed my gasket with motoseal which should bridge the gap..

The top end was glued on very well, i had to tap it with a mallet to unglue it.

I may pull the top end and set up a mic and see whats what. I also dabble in machining at home so I could easily measure it.

If push comes to shove I may pull the saw down and install the matching right side case.

Before i do that though im going to see if i can swapp the intake with the jug still on. That bottom screw is a pain to get at.

Thankyou..
 
After work today I gave the 576 another go.

I replaced the intake manifold, impulse line, fuel line and tank vent (again), spark plug and for fun put another flywheel on..

I also rebuilt one of the spare carbs I have here to try that.

Saw seems to run better but it still seems lean at idle once hot. The chain spins just a bit after a long cut..

The plug looks perfectly golden brown so its not lean.

I may take this saw over to my buddies and cut some wood this weekend to see if maybe the autotune will settle it down after a tank or 2.

At this point the only original parts on this saw are the muffler, top end and right side case.

I'm almost ready to give up.

I may order another set of gaskets and crank seals and build another saw around the other right side case and the left case thats currently on the saw.. I guess if i tear it completely down to bare cases and start ground up thats the only way I can say I've done all I can do.

I hate this saw lol!!!
 
Another update..... Problem fixed!!

So as some of you know this saw has been a thorn in my side since day one. Saw ran fine til it got hot and then would refuse to go back to idle amd idle erratically..

It would pass pressure and vac tests. Been throwing parts at this saw for 6 months, nothing would make it run right. Thank god im sitting on a ton of 576 parts.

So that brings me to this morning.. I worked on a new poulan homeowner saw for a buddy on weds. Saw had a zama carb of some kind, similar to the carb on the 576 just smaller. It had running issues.

The poulan zama had a loose throttle plate which is the part that houses the throttle and air injection butterflys. The screws were backed out.

That gave me an idea....

I checked the screws on the brand new 576 carb off my saw and they werent loose but weren't what I would call tight either.

I pulled off the throttle plate assembly and noticed that theres a plastic plug behind the throttle plate that seals off a hole that goes into the H circuit. That plug isn't on the IPL for that carb and isn't present on the AT carbs I have. Had no clue it was there.

The plug was leaking fuel, there was fuel all over the throttle plate gasket in the area behind where that plug sits. I noticed it right away.

So I cleaned the cavity where that plastic plug seats and sealed it with motoseal. I also put motoseal on the throttle plate gasket and stuck it back on the carb.

I then put the carb back on and tried the saw.

First thing I noticed was that the saw ran different. It was VERY rich at idle and was idling very slow. (Hummmmm almost like someone was tuning around an "air leak" :) )

Had to turn in the L jet 3/4 turn and the idle screw 1 turn to get it to idle.

Just put a tank through the saw and with some tuning it now runs like a top and more importantly doesn't lean out after a big cut!!!!

This saw has been a battle, cost me some time and some money but I got it beat!.

Hopefully this thread will help someone else down the line.
 

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