562xp Hot start?

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Until Husky reprograms the auto tune for hot weather if they can get by the EPA, I'd try and do some light cutting at higher RPM's to cool the saw down some and let it idle a bit before shutting it off. No long hard cuts before shutting it off. Steve
 
Until Husky reprograms the auto tune for hot weather if they can get by the EPA, I'd try and do some light cutting at higher RPM's to cool the saw down some and let it idle a bit before shutting it off. No long hard cuts before shutting it off. Steve

That is always good advice for any saw really. I did however let the saw idle between cuts, and for about a minut before I shut her off.

Did Husqvarna not test these saws in different environments? Sometimes I wonder.
 
One is to use the choke to kill the machine.
I have tried that a few times when my (non-562) saws vapor lock - sometimes I thought it helped a little, but it's hard to tell. If it has an effect it isn't a large one.
 
Watched your video....I don't have any intelligent input. None of mine react that way. Almost like the fuel system/hoses are loosing prime. Maybe a leak in that system somewhere. Sounds like a derivative of fuel starvation. My humble opinion is I hope the dealer takes that saw and sends it back to Husqvarna R&D! Certainly something off on that saw. I read vapor lock in some of the commentary ... is that an ethanol blend? Does the fuel cap act like its under pressure? Something in the tank/handle, hoses, and/or carb must be off. Doubt it has anything to do with "autotune" and more to do with simple fuel delivery issues.

Heard you mention the primer bulb was empty...that's got to be a symptom of a larger issue in that tangled mess of hoses. Being a new saw should be a warrantee issue. If it as an older saw I would tear it apart looking for defective seals in the intake tract and things along the line of thought. Pulse issues. Carb issues. etc.

Of course I'm a little frustrated right now with 62cc Husqvarna's . Got a friends 262 the was having air leak symptoms...simply started taking things apart and stuff just crumbles! That plastic dam around the intake manifold .. crumbled. The plastic main seal cap.. The ignition coil....crumbles. The rubber parts in the carb.... a can of worms! And a lot of the plastic stuff is hard to find. Rather be debugging a 562! At least I can find parts
 
Watched your video....I don't have any intelligent input. None of mine react that way. Almost like the fuel system/hoses are loosing prime. Maybe a leak in that system somewhere. Sounds like a derivative of fuel starvation. My humble opinion is I hope the dealer takes that saw and sends it back to Husqvarna R&D! Certainly something off on that saw. I read vapor lock in some of the commentary ... is that an ethanol blend? Does the fuel cap act like its under pressure? Something in the tank/handle, hoses, and/or carb must be off. Doubt it has anything to do with "autotune" and more to do with simple fuel delivery issues.

Heard you mention the primer bulb was empty...that's got to be a symptom of a larger issue in that tangled mess of hoses. Being a new saw should be a warrantee issue. If it as an older saw I would tear it apart looking for defective seals in the intake tract and things along the line of thought. Pulse issues. Carb issues. etc.

Of course I'm a little frustrated right now with 62cc Husqvarna's . Got a friends 262 the was having air leak symptoms...simply started taking things apart and stuff just crumbles! That plastic dam around the intake manifold .. crumbled. The plastic main seal cap.. The ignition coil....crumbles. The rubber parts in the carb.... a can of worms! And a lot of the plastic stuff is hard to find. Rather be debugging a 562! At least I can find parts

Non ethanol fuel, the saw is on it's fifth tank. I'm not worried about the dealer taking care of me, you should know he's in many of your videos ;). I doubt it's directly an AutoTune issue as well. When you remove the cap on a hot saw their will always be some pressure.

In the end I believe the saw became too hot, and the fuel started vaporizing in the carb, when that happens the primer will no longer be able to pull fuel. I highly doubt the saw has a leak of any type because it runs 100% perfect until it's shut off. With that said I really do not know for sure without going through the saw. I'll give our dealer a call this week before I do anything, the saws just too new to play with IMHO.

Your input is greatly appreciated. :cheers:
 
Non ethanol fuel
I've had a suspicion for a some time that much of the non-ethanol fuel may not really be so. This was a quote from the thread I started on vapor lock some time ago:

"Volatility and distillation
Ethanol forms azeotropes with hydrocarbons of gasoline, which impacts volatility. In particular, the vapor pressure and distillation characteristics of ethanol/gasoline blends are non-linear. Blending vapor pressures for alcohols are significantly higher than their nominal vapor pressures. Vapor pressure of neat ethanol is low at only 16 kPa (Owen and Coley 1995). When ethanol is added into gasoline, vapor pressure increases with blending ratios of 5-10%, but then gradually declines (Figures). With ethanol content of some 30-50%, vapor pressure is at the same level as for gasoline without oxygenates (Environment Australia 2002, Furey 1985).


Vapor pressure of blends can be adjusted by using base fuel with low vapor pressure. If strict fuel specifications are to be met, this rules out the possibility of so-called splash-blending of ethanol. In some regions, higher vapor pressures are allowed for gasoline-ethanol blends, if they contain ethanol (Read more of volatility limits).


One notable point regarding the vapor pressure of ethanol blend is its tendency to increase more quickly than that of gasoline with increasing temperature."

From: http://www.iea-amf.org/content/fuel_information/fuel_info_home/ethanol/e10/ethanol_properties
 
wonder if there would be a different result with those "fuel in a can" products that are for certain non ethanol. At least a fuel from a different source. I am pretty certain if the issue is generic...I'm going to hear about it this week.. A couple of my older saws are being "tested" in the logging world out here. And its been hot.
 
It's all about the heat guys. The changes to the top covers that Walter showed in the pics are good for about 10 degrees. It does indeed make a difference; in many cases the problem goes away. It at least shortens the window where the issue occurs. Hot start issues are characteristically like this:

30 seconds or less, or 5+ minutes, it usually starts right up. The critical time is generally in that 2-3 minute range where the heat has peaked, yet hasn't had time to dissipate. Any additional heat evacuation makes a difference, and often that 10 degrees is enough. But if the temp goes up past 90, then the margin of improvement from the top cover is diminished. The reason the saw will restart immediately, but not 2 minutes later is due to the heat sink effect where the cylinder radiates it's heat into the carb while it's not running or receiving any cooling air flow.

Hitting the primer often flushes the offending fuel out of the carb in favor of what's in the tank, unless it's so bad that the primer wigs out like Andy's is doing. I've been cutting the covers on every saw, orange or red that comes into the shop. Both the 62 and 50 CC families. Everyone says it's better, but with the temps being what they are half the guys say it will still happen sometimes.

So, first thing is to cut the top and see what kind of improvement you notice. I just do it with a utility knife. Have done a couple dozen so far without having to reach for the box of band-aids. :)
 
It's all about the heat guys. The changes to the top covers that Walter showed in the pics are good for about 10 degrees. It does indeed make a difference; in many cases the problem goes away. It at least shortens the window where the issue occurs. Hot start issues are characteristically like this:

30 seconds or less, or 5+ minutes, it usually starts right up. The critical time is generally in that 2-3 minute range where the heat has peaked, yet hasn't had time to dissipate. Any additional heat evacuation makes a difference, and often that 10 degrees is enough. But if the temp goes up past 90, then the margin of improvement from the top cover is diminished. The reason the saw will restart immediately, but not 2 minutes later is due to the heat sink effect where the cylinder radiates it's heat into the carb while it's not running or receiving any cooling air flow.

Hitting the primer often flushes the offending fuel out of the carb in favor of what's in the tank, unless it's so bad that the primer wigs out like Andy's is doing. I've been cutting the covers on every saw, orange or red that comes into the shop. Both the 62 and 50 CC families. Everyone says it's better, but with the temps being what they are half the guys say it will still happen sometimes.

So, first thing is to cut the top and see what kind of improvement you notice. I just do it with a utility knife. Have done a couple dozen so far without having to reach for the box of band-aids. :)

Thank you for checking in Bob!! What you said is pretty much the conclusion I've come to.

I was thinking about trying some canned fuel just to see if it makes any difference, but honestly I've been running fuel from the same pump for two years without a problem.
 
What if you pop the top cover off if you know it is going to sit a few minutes.
I know it could be a pain and not always applicable.
But is a lot easier then pulling 100 times.
 
What if you pop the top cover off if you know it is going to sit a few minutes.
I know it could be a pain and not always applicable.
But is a lot easier then pulling 100 times.
I have been thinking about making some additional ventilation openings at some point, if you mess it up a top cover isn't the most costly part.
 
Of course I'm a little frustrated right now with 62cc Husqvarna's . Got a friends 262 the was having air leak symptoms...simply started taking things apart and stuff just crumbles! That plastic dam around the intake manifold .. crumbled. The plastic main seal cap.. The ignition coil....crumbles. The rubber parts in the carb.... a can of worms! And a lot of the plastic stuff is hard to find. Rather be debugging a 562! At least I can find parts

Yeah, I mean no way anything like that should happen on a saw that's only 20 some years old. :dancing:

The sealing collars are only $6 and are still available. I know of one dealer who stocks them. :)

The plastic main seal cap, is called the generator holder. Which technically it is if you have a G model. Early ones were made of aluminum; not sure when they switched to plastic. This part unfortunately is NLA. Parts saws-parts saws-parts saws. Grab 'em all. No matter how ratty it looks, there's always something there you can use. That seal is the same seal used on the 372, 357, 55 and some others. Obviously it would have been better if they mounted it in the case on the 262 chassis like the rest of them and there'd be no cap/holder to be looking for. Lot of parts for this family are going the NLA route. :(
 
I have been thinking about making some additional ventilation openings at some point, if you mess it up a top cover isn't the most costly part.

I "ventilate" the muffler too.. drops heat from the front of the cylinder & cases under the muffler.

In addition removing the decomp leaves a ugly hole on top...but its a hole..:)
 
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