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

[Old2stroke]

When you press the bulb and it doesn't feel like it is pumping fuel, it can be because the main jet nozzle check valve is sticking open and the bulb is just sucking air back through the valve rather than fuel from the tank through the carb. Can also let air bleed back into the low speed circuit where is will upset the idle and prevent the transfer port from supplying enough fuel to let the engine transfer from idle to high speed. When this fault occurs it usually shows up as bad idle issues and not really temperature related. Since your problem is more related to hot temperature soaking, vapour lock sure seems to be the most likely culprit. Good old autotune can be making the whole diagnostic procedure messy as well.

 

[KingDavey]

Make sure there is no ethanol in your fuel. My 562 wouldn't pull a purge, but was also boiling fuel in the tank when hot. I switched to non ethanol 98 octane(sunoco gtx 260, only non ethanol available) and it ran and restarted like a champ.

 

[Chris-PA]

Make sure there is no ethanol in your fuel. My 562 wouldn't pull a purge, but was also boiling fuel in the tank when hot. I switched to non ethanol 98 octane(sunoco gtx 260, only non ethanol available) and it ran and restarted like a champ.

From what I have read somewhere around 10% ethanol has a much higher vapor pressure. I can tell you that on a 95F day in the summer if it's off for a couple of minutes, or less, it will vapor lock.

 

[MountainHigh]

Make sure there is no ethanol in your fuel. My 562 wouldn't pull a purge, but was also boiling fuel in the tank when hot. I switched to non ethanol 98 octane(sunoco gtx 260, only non ethanol available) and it ran and restarted like a champ.

I always buy 92 or 94 octane non-ethanol gas (never seen 98 here), but just ran across a thread where someone mentioned the switch over at the pump dumps .8 gallon of the previous fuel into your non-ethanol purchase, as the hose itself holds some from the previous user (something that I suspected but never assumed it would be that much). So, from here on, I'm going to put the first big gulp of non-ethanol gas from the pump into my vehicle, and then fill my gas can.

Heading up the mountain tomorrow and will run my saw hard and report back after I see what happens not using the purge bulb and the decomp on warm restart. My 346xp is coming along in case the 562 acts up !

Great feedback on this thread!

 

[MountainHigh]

So ... I ran the saw steady at full throttle for about an hour in the wood in total today, on fresh 92 octane no ethanol (bought this AM) 50 to 1 mix. Cut a few cords of wood. Switched saw off and back on several times throughout without any glitches and using the suggested hot re-start no-decomp and no purge technique. I was beginning to think that this may be all that the saw needed, until I stopped to sharpen the chain. Restart, once again with UP/Down for hot start, no decomp and no purge, but this time I pulled 10 times and nothing, then looked at the bulb and no fuel - cracked open the gas tank and heard the familiar fizz. Pulled another 20+ times with no success - tried full throttle start, tried choke, tried everything, still no go.

Muttered a few choice words and threw the saw back in the truck. Cranked up my 346 and finished the cut. 562 is going to the dealer next week after I get through this next few days cutting with my 346.

 

[Topbuilder]

Bummer. I was hoping we fixed you. I look forward to the dealer report.

 

[MountainHigh]

Bummer. I was hoping we fixed you. I look forward to the dealer report.

thanks for taking the time to try and work this out. I'll re-post when I hear from the dealer ... hoping they've got their heads around the software for these things by now ... we'll see.

 

[Cycledude]

Have similar hard start when hot issues with my one year old 562, cold it starts fine, love the saw when it starts like it's supposed to, will be interesting to hear what the dealer does for you, mine came with a 4 year warranty and they replaced the carburetor last year, it definitely gained power but the hard hot start issue didn't change.

 

[Cycledude]

we had two 562xp's come through our shop with a similar issue..try to put an up-dated breather and plug...part # 513751501 and 537051801..this worked on both saws..Husqvarna tech support can walk you through this..

Thanks for the tip chainsaw wizard ! I suspect you are correct and this will cure the hard hot start issues with my 562, and warranty should cover it.

 

[Chris-PA]

So ... I ran the saw steady at full throttle for about an hour in the wood in total today, on fresh 92 octane no ethanol (bought this AM) 50 to 1 mix. Cut a few cords of wood. Switched saw off and back on several times throughout without any glitches and using the suggested hot re-start no-decomp and no purge technique. I was beginning to think that this may be all that the saw needed, until I stopped to sharpen the chain. Restart, once again with UP/Down for hot start, no decomp and no purge, but this time I pulled 10 times and nothing, then looked at the bulb and no fuel - cracked open the gas tank and heard the familiar fizz. Pulled another 20+ times with no success - tried full throttle start, tried choke, tried everything, still no go.

Muttered a few choice words and threw the saw back in the truck. Cranked up my 346 and finished the cut. 562 is going to the dealer next week after I get through this next few days cutting with my 346.

Can you take a guess at the length of time you had it off where it did restart vs. when it didn't (when you sarpened the chain)?

I know on mine I've gotten pretty fast at refueling so I can get it going again.

On the other hand, how warm is it there now? And what elevation?

 

[MountainHigh]

Can you take a guess at the length of time you had it off where it did restart vs. when it didn't (when you sarpened the chain)?
I know on mine I've gotten pretty fast at refueling so I can get it going again.
On the other hand, how warm is it there now? And what elevation?

The length of time issue, I'm a little fuzzy on this but I'll give it a try . . .

Hot start problem always seems to be only an issue after I've ran it hard full throttle for a while, maybe bucking a couple of 30' logs in sequence.
I'm not exactly sure of the length of time when off, but it definitely restarted easily early on in the cutting if turned off and only left for one or two minutes.

The saw was ALWAYS quite hot when it would not restart and I'm guessing that each time it would not restart, it had been off for several minutes, however, yesterday I was watching the purge bulb on the saw after bucking a couple of logs as I turned it off, and tried restarting, sure enough, she would not start even with no-decomp/no purge, and when I did finally try the bulb, there was still zero suction - had to let it sit 15 minutes before it would start. Pulled air filter and the inside of the carb was slightly wet with fuel. Didn't have 5/8 driver to pull the plug, but did so when I got home - nice healthy medium brown colour looked good. I could be wrong, but overall it seems to be mostly an issue of the amount of heat and hard running of the saw, rather than any time factor of it sitting idle. I also noticed a slight carbon buildup around the base of the decomp button so maybe a tiny leak there? I'll let the dealer fiddle with that.

The times when the Vapor lock (at least that's what it seems like) has occurred, it has always been warm outside - not blistering hot by any stretch, just warm. Was 24C (75F) on the slope yesterday at about 2000' level. I did notice it vapor locking once last year in August on a scorching hot day, but it definitely seems to be getting worse and is doing it far more frequently now.

 

[Termite]

we had two 562xp's come through our shop with a similar issue..try to put an up-dated breather and plug...part # 513751501 and 537051801..this worked on both saws..Husqvarna tech support can walk you through this..

Is this breather the tank vent. I searched and could not find a picture of it.

 

[Cycledude]

I thought you dropped it off at a dealer Wednesday but now it sounds like your still using it ?
Whatever the issue with your saw is it sounds almost exactly like mine, in my case it only happens when the saw is hot, it can be below freezing or over 70 degrees, when the saw gets hot it doesn't like to start. I'm guessing that Chaisaw wizards tip is the correct fix but was hoping you would report yours was fixed before taking mine back again.

 

[Chris-PA]

The length of time issue, I'm a little fuzzy on this but I'll give it a try . . .

Hot start problem always seems to be only an issue after I've ran it hard full throttle for a while, maybe bucking a couple of 30' logs in sequence.
I'm not exactly sure of the length of time when off, but it definitely restarted easily early on in the cutting if turned off and only left for one or two minutes.

The saw was ALWAYS quite hot when it would not restart and I'm guessing that each time it would not restart, it had been off for several minutes, however, yesterday I was watching the purge bulb on the saw after bucking a couple of logs as I turned it off, and tried restarting, sure enough, she would not start even with no-decomp/no purge, and when I did finally try the bulb, there was still zero suction - had to let it sit 15 minutes before it would start. Pulled air filter and the inside of the carb was slightly wet with fuel. Didn't have 5/8 driver to pull the plug, but did so when I got home - nice healthy medium brown colour looked good. I could be wrong, but overall it seems to be mostly an issue of the amount of heat and hard running of the saw, rather than any time factor of it sitting idle. I also noticed a slight carbon buildup around the base of the decomp button so maybe a tiny leak there? I'll let the dealer fiddle with that.

The times when the Vapor lock (at least that's what it seems like) has occurred, it has always been warm outside - not blistering hot by any stretch, just warm. Was 24C (75F) on the slope yesterday at about 2000' level. I did notice it vapor locking once last year in August on a scorching hot day, but it definitely seems to be getting worse and is doing it far more frequently now.

Perhaps this is something else then. For my saws vapor lock will happen if I shut them off while hot and leave them off for a bit. If I restart them soon enough the fuel has not boiled yet and they'll go again, but if I leave them off too long it's done. Some models are easier to get going again than others - I actually think the plastic cased saws have an advantage here as the case is not thermally conductive.

 

[MountainHigh]

I thought you dropped it off at a dealer Wednesday but now it sounds like your still using it ?
Whatever the issue with your saw is it sounds almost exactly like mine, in my case it only happens when the saw is hot, it can be below freezing or over 70 degrees, when the saw gets hot it doesn't like to start. I'm guessing that Chainsaw wizards tip is the correct fix but was hoping you would report yours was fixed before taking mine back again.

I cut wood this past Wednesday and Thursday. Used the opportunity to run the saw hard using the techniques described here and see what happened. It still acted up, so I'll take it into my dealer soon ... maybe tomorrow or Monday, depends on when I want to fight traffic and can get away.

You may want to take yours in rather than waiting for my results. I don't expect I'll have an answer from them in the short term, they are old school guys and may not be proficient on diagnosing autotune saws yet. When I know more, I'll post my results here. I'm going to push for a new EL48 carb and latest software, as well as suggest Chainsaw Wizard's " up-dated breather and plug...part # 513751501 and 537051801", and a new cover with the hole in it (failing that, I'll take my drill and make my own holes), as possible solutions.

Best of luck.

Just looking at 562 Parts List and note this:
Cylinder cover 587 24 87-02 was 587 24 87-01. One hole added and a wall has been partly cut in order to improve the air flow for increased cooling of the engine.

I'm still looking for Chainsaw Wizard's suggested part items. Striking out so far. I'm guessing it is a new decomp/plug?

 

[MountainHigh]

Perhaps this is something else then. For my saws vapor lock will happen if I shut them off while hot and leave them off for a bit. If I restart them soon enough the fuel has not boiled yet and they'll go again, but if I leave them off too long it's done. Some models are easier to get going again than others - I actually think the plastic cased saws have an advantage here as the case is not thermally conductive.

Ya that sounds like mine as well, but mine is vapor locking every time I run it hard now, on moderate warm days or not, if I turn it off after a certain amount of use - it's done. If I've run it down to 1/8th tank and stop to file the chain because I'm into some dirty wood, it's done! You'd think XP saws 'should' be able to run all day without enforced multiple long coffee breaks after each fillup or chain tweak. My 346 sure can!

Thanks for the feedback.

 

[Gugi47]

Sorry, I think that was me using the wrong wording. I didn't check the sparkplug, I just didn't get enough of an ignition to push the decompression button back up.

I never use the decompression button.
Always start 2nd pull (cold) and 1st (hot) after I fill the reservoir again.
Never run out of gas from reservoir.
When fill with gas, fill with chain oil to and then you have a smooth run.

 

[hamish]

Seriously, just change out the tank vent.

From 2014 week 43,Tank ventilation kit 587 64 54-01.

Even if you swap it out for an original it will most likely solve the problem.

513751501..........try looking at the 543XP or basically a differential vent on most older 4x4 vehicles with extended vent hoses. . 537051801 just a plug to bypass the primer inlet, not relevant on the 562, nor required.

Let me guess when you try to warm start it, it pops and fires then dies, over and over again.

 

[MountainHigh]

Seriously, just change out the tank vent.
From 2014 week 43,Tank ventilation kit 587 64 54-01.
Even if you swap it out for an original it will most likely solve the problem.

513751501..........try looking at the 543XP or basically a differential vent on most older 4x4 vehicles with extended vent hoses. . 537051801 just a plug to bypass the primer inlet, not relevant on the 562, nor required.

Let me guess when you try to warm start it, it pops and fires then dies, over and over again.

I think mine has popped and then died occasionally on warm start as you say, but most of the time it just won't do anything, except wear out my shoulder. No pop or firing, It's just deader than a door nail for 15 or 20 minutes.

Thanks for the feedback on Tank ventilation kit 587 64 54-01. I'll tell the local guys to look at this. What do you think of getting an el48? Is staying with an el46 asking for trouble in the future?

 

[Cycledude]

Any progress ? really don't need my saw right now so I'm kinda waiting to hear how yours turns out before taking it in again.