562xp warm start trouble, air purge stops working for a while

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I'd be making up some sort of heat shield to reflect heat and protect affected areas out of foil stuck to card or something. I know with the price you pay for these saws one should expect them to run right out of the box but....
 
What data does it give you? Just a max temp?

Anyway, if it shows temps at the carb of that value, then there is the evidence. A carb cannot pump vapor so it can't work at such temperatures. How could the carb get that hot while running with air flowing through it? Seems like those must be hot soak temps.

It gives you a max temperature (since its last reset) and also a min/max/avg of the starting temperature, with a run time over over 1 min. So pointless in this regard.

The incoming air/fuel mix charge cools the motor. On any chainsaw, the carb is the coldest part of the saw, the temperature values in this aspect are very close to the ambient temperature in warm climates.
 
I remember mine saying max carb temp somewhere around 70 degrees celsius , 394 and 3120's were always bad for the same problem in summer all the boys would refill them with fuel while they were still running because you'd be to scared to shut them off
 
How about the routing of the fuel line, any chance that it's in a hot spot?
You guys have gotten me curious now.
 
Took my trusty 346 up the mountain today and got another load really nice birch, maple and fir. Great little saw but I sure miss the angry 562 beast in anything over 12 inches wide. Even with several tweaks to keep a razar sharp chain, I found I was leaning on my 346 pretty hard to try to pick up the pace - giddyup little doggie :D

I suspect I won't hear more from my dealer about my 562 until next week. They will be hard pressed to repeat my problem, unless they have two 30' logs out back of the shop (which they don't) to get her breaking a good sweat. I envisage huddling over a computer screen with phone calls to Husqvarna to try to fix the problem. While it may not solve all the problems, it would sure be fun for us computer hacks to be able to plug our own saws into a PC on a regular basis.

I'll post when I hear back.
 
I remember mine saying max carb temp somewhere around 70 degrees celsius , 394 and 3120's were always bad for the same problem in summer all the boys would refill them with fuel while they were still running because you'd be to scared to shut them off

The carb would have stopped working along time before it hit 70C.

The accolade of the hot refueling has only to do with inability of knowing how to re-start a warm saw, for vent issues and refuelling would have prevented the hot refueling from taking place. A saw cant be vapour locked if you have vented it by opening the fuel cap, nor can it be over-pressurized after opening the fuel cap.
 
A saw cant be vapour locked if you have vented it by opening the fuel cap
I disagree based on experience. The carb is only the coolest part of the saw when the saw is running, but that is not when this problem occurs. Once the saw is off then the carb is a small chunk of cool aluminum next to a much larger, much hotter chunk of aluminum/mag. The temperature of the engine will begin to drop, and the temperature of the carb will begin to heat, and the temperature rise of the carb will be much faster since the mass is much less. Once it gets to the boiling point of the fuel it can no longer pump or operate.

The fuel pump is in the carb, and both the pump and the venturi operate by drawing fuel from the tank - that is to say they reduce the pressure of the fuel at the carb end of the line so that fuel will flow from the tank to the carb. And reducing the pressure reduces the boiling temperature. Actually any positive pressure in the tank will be a help, and opening the tank and venting it only makes the problem worse. Still, the function of the metering diaphragm is to hold the fuel in the metering chamber at a fixed amount below atmospheric pressure - if it's close to boiling the carb simply can't work.
 
Ive been through all the same crap with mine and theres no fix they just run too hot , dunno if its from been strato , the angled back head been to close to the carb , massive muffler acting as a heat soak or the engine cover been to tight around the cylinder to allow good airflow or all of the above but they just get vapor lock and refuse to go.

That's depressing!

Their new saw cover might offer some better cooling - This new cover clearly shows Husqvarna is well aware of an overheating problem and is trying to cool the saw down with more ventilation -I'm hoping they also have some other fixes I may find out about.

Any thoughts about just ripping the guts out of the muffler as an unofficial start to reducing heat, along with drilling a large ventilation hole similar to the new cover, if all else fails from the dealer?
 
I disagree based on experience. The carb is only the coolest part of the saw when the saw is running, but that is not when this problem occurs. Once the saw is off then the carb is a small chunk of cool aluminum next to a much larger, much hotter chunk of aluminum/mag. The temperature of the engine will begin to drop, and the temperature of the carb will begin to heat, and the temperature rise of the carb will be much faster since the mass is much less. Once it gets to the boiling point of the fuel it can no longer pump or operate.

The fuel pump is in the carb, and both the pump and the venturi operate by drawing fuel from the tank - that is to say they reduce the pressure of the fuel at the carb end of the line so that fuel will flow from the tank to the carb. And reducing the pressure reduces the boiling temperature. Actually any positive pressure in the tank will be a help, and opening the tank and venting it only makes the problem worse. Still, the function of the metering diaphragm is to hold the fuel in the metering chamber at a fixed amount below atmospheric pressure - if it's close to boiling the carb simply can't work.

With the initial boiling point of mix fuel being just under 100F.............every saw would experience this. So back to the drawing board. But yes agree 100% with everything else.
 
With the initial boiling point of mix fuel being just under 100F.............every saw would experience this. So back to the drawing board. But yes agree 100% with everything else.
Winter fuel blend & E10 increase the vapor pressure. Many of my saw do it. I promise you it's real.
 
To repeat what I wrote up thread, many parts of a carb function by reducing the pressure on the fuel relative to atmospheric, and reducing the pressure also reduces the vaporization temperature.
 
WTF ! Dealer called - they tell me cylinder is scored and saw is toast!!! :surprised3:
No other word from them on anything that was on my laundry list.

They started out saying warranty will not cover this even though I have extended warranty. NO WAY! I told them I run same 91 octane 40 to 1 or 50 to 1 mix in both saws and my ancient 346 runs like a top! They tell me Husky usually says its the customers fault for running bad gas.

Looks like I'll be speaking with Husky on Monday! Correction - Husky Rep on Thursday.

Only thing I can think of is carb was running way too lean / air leak - or maybe dust creeping past filter?
I'm not even sure they put this saw on the diagnostic software! Edit - I just called back and they haven't run diagnostic software. :eek:

The fun begins :omg:
 
WTF ! Dealer called - they tell me cylinder is scored and saw is toast!!! :surprised3:
No other word from them on anything that was on my laundry list.

They started out saying warranty will not cover this even though I have extended warranty. NO WAY! I told them I run same 91 octane 40 to 1 or 50 to 1 mix in both saws and my ancient 346 runs like a top! They tell me Husky usually says its the customers fault for running bad gas.

Looks like I'll be speaking with Husky on Monday! Correction - Husky Rep on Thursday.

Only thing I can think of is carb was running way too lean or maybe dust creeping past filter?
I'm not even sure they put this saw on the diagnostic software! Edit - I just called back and they haven't run diagnostic software. :eek:

The fun begins :omg:
If there was an air leak that was beyond what the AT system could compensate for, it could have caused the damage as well as excess engine heat, which would have made heat soak/vapor loch worse. Kind of fits - but there's no need to guess since the data from the AT system should show it if that's what happened.

Maybe they need to add a check engine light to the AT system? Seriously. The system knows if it's at the limits of its range, and that this is a sign of a major problem. Wouldn't that be very valuable info to share with the operator?
 
WTF ! Dealer called - they tell me cylinder is scored and saw is toast!!! :surprised3:
No other word from them on anything that was on my laundry list.

They started out saying warranty will not cover this even though I have extended warranty. NO WAY! I told them I run same 91 octane 40 to 1 or 50 to 1 mix in both saws and my ancient 346 runs like a top! They tell me Husky usually says its the customers fault for running bad gas.

Looks like I'll be speaking with Husky on Monday! Correction - Husky Rep on Thursday.

Only thing I can think of is carb was running way too lean / air leak - or maybe dust creeping past filter?
I'm not even sure they put this saw on the diagnostic software! Edit - I just called back and they haven't run diagnostic software. :eek:

The fun begins :omg:
Same thing happened to me back in December. I had the saw about 9 months. 107 hours in it. It has the same symptoms as yours does now. They tell me it's because of bad gas... they call me 30 mins later and say the decomp had a leak and cylinder is scorched. Now they say I get a new saw..... now 4 months later on the 2015 new saw it's doing the same thing my 1st 2014 saw they replaced is doing! It may need a trip to the dealer:mad:
 

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