562 Heat Management

[Sprinter]

I have an older 562 from week 8 2012. Still has the 44B carb and has not been software updated.
Hot start has not been a problem probably because I work Mostly in the spring & fall. But as heat problems seem to be a big issue I've been worried about longevity!

Now to the good stuff!

So here's what I've done about it.
1) muffler mod - (@HolmenTree)
2) top cover vent - (@afleetcommand)
3) added insulating tape to partition under top cover.
4) opened top cover vent & removed air nozzle.

I understand that this last item will be of concern. I did try the carb vent with the air nozzle in and found positive pressure. Possibly, even a bit of intake boost. But, at the moment I am more interested in heat than power! So I'm going without air injection, in favor of lower intake temp and more cooling airflow over the cylinder. It should be noted that items #3 & 4 are easily reversible.

This afternoon, went to the wood pile and cut a couple dozen cookies, maybe more.
With my Fluke IR temp sensor I got the following readings from the top cover around the partition.
Temp above ambient
Front: 107F +25F
Rear : 87F +5F
Ambient: 82F

As a side note, I got an autotune print out at 10 hours that showed a Max. carb temp of 117F at 10 hours, witch was normal. Low start temp was 33F while average was 73F at start.

Of coarse, these are not head or carb temps but they should be relative. It's amazing the the carb temp was only 5 deg more than ambient. I wish I had temps from before as I believe those little bits of insulating tape (1" x 4") may have made the big difference.

(edit) Just found temps from a previous run without the air inject delete.

Temp above ambient
Front: 97F +40F
Rear: 67F +10F
Ambient: 57F


Different set of numbers but makes more sense when you look at them as difference above ambient. Hope this makes sense!

Thanks for your patience, Fred

 

[porsche965]

When I'm running in heat like the 90s I let it idle for 15 seconds or so and then choke it out. Restart on High Idle, no choke. Seems to make a big difference.

Nice work on your saw.

 

[kneedeepinsaws]

Good call on the air injection blockage for more cooling. If you look carefully, there is also air duMped under the muffler too.
I found the biggest problem was the fuel line hose connecting the tank to the air box is right beside a piece of magnesium case. It gets really hot there, insulating the hose could prevent the hot start issues. I already have but have not had enough run time to tell you if it worked in hot weather since it was done

 

[Sprinter]

Good call on the air injection blockage for more cooling. If you look carefully, there is also air duMped under the muffler too.
I found the biggest problem was the fuel line hose connecting the tank to the air box is right beside a piece of magnesium case. It gets really hot there, insulating the hose could prevent the hot start issues. I already have but have not had enough run time to tell you if it worked in hot weather since it was done

I guess that fuel line issue was why they changed to the shorter hose. Mine is still original, so I'll keep it in mind.
Hopefully, it will be okay with better cooling.
One problem I am having is is fine saw dust in the filter, as expected. At the moment I'm trying a fine mesh pre-filter.
We are going into some old bug-kill pine shortly, so I should get a good test.

 

[Moparmyway]

I grease the filter plastic in the recess, so the carb elbow seals against the grease in the crease. Fines have stopped getting in

 

[kneedeepinsaws]

You can also slip a thin larger o-ring in the recess of the filter.

rtving the two halves shut is a good addition for protection

 

[Sprinter]

I am less concerned with fines getting by the filter than plugging the filter. The way I see it is , there will be sawdust and I have to find a balance in filtration without choking off the intake. I want to stop as much as possible from getting to the filter without making it worse. No point in a pre-filter if it won't pass enough air or keeps plugging up.
Maybe, I'll have to carry a spare filter to the filter.

 

[srcarr52]

I've seen a few people put a frogskin over a hole on the right side of the airbox and leave the air inject intact. The airboxes are pretty well sealed so adding the hole allows for more air to move across the carb and keep it cool, it also seems the extra flow into the air inject reduces the amount of fines sent to the airbox.

 

[Sprinter]

I think I'm getting ahead of myself and over-reacting. I'll find out soon enough.

 

[Moparmyway]

I've seen a few people put a frogskin over a hole on the right side of the airbox and leave the air inject intact. The airboxes are pretty well sealed so adding the hole allows for more air to move across the carb and keep it cool, it also seems the extra flow into the air inject reduces the amount of fines sent to the airbox.

But the more air that goes to the airbox, the less air for cooling the cylinder, no ?

 

[Sprinter]

That's right! It's why I pulled the Air Nozzle. Much cooler without it.

To control dust to the air filter, I made a loose fitting bag out of breathable nylon cloth and tucked it around the filter.
Filter stays clean and if I pull the bag off and give it a shake it's ready to go again.

I think I'm happy, time will tell.

 

[cuinrearview]

The o-ring at the filter base works well.

 

[srcarr52]

But the more air that goes to the airbox, the less air for cooling the cylinder, no ?

Hard to say, it's probably negligible. The air inject nozzle might help direct the air flow off the fan for more even cooling.

 

[Sprinter]

I need to apologize for my lack of clarity in my original post. As I was trying to get he message out I made several edits which may have confused the issue.
Two changes from stock made the most difference. First, the insulation on the under cover partition made a real difference. You can feel the change as you pass your hand over the cover.
The biggest benefit in terms of heat was the Air Injection delete. No need for temperature numbers. You can feel it with your hand.
A 25 degree reduction in cover temperature!

 

[Moparmyway]

Hard to say, it's probably negligible. The air inject nozzle might help direct the air flow off the fan for more even cooling.

Nah, it grabs air like the 395 tube does, except much smaller and it routs it through the case half then into the very well sealed airbox instead of up and over the case half.
I’ve pulled mine off and taped the opening closed. It’s definitely got more air across the cylinder now.

Long skinny Frogskinz across the back of the top cover for the win !!!

 

[Sprinter]

You got it for the win!

 

[kneedeepinsaws]

When I'm running in heat like the 90s I let it idle for 15 seconds or so and then choke it out. Restart on High Idle, no choke. Seems to make a big difference.

Nice work on your saw.

I hear you, but it is not enough of a difference to eliminate the 562 heat problem.
I have had mine idle for 3-4 minutes after cool down, but if it sits for 10 minutes it will not start.
I think the air injection delete is a good idea.

i am not convinced that the vapor lock issue is related to the airbox. I am very sure that it is the fuel line just near the case boss under the cover. Its very close to it and it geta very hot. This would explain why the primer bulb does not work just before the unit will not start or Start bog and then stall when hot.
Keeping the engine temps down would in turn prevent heat from getting to the case boss that is near the fuel line under the filter housing. So the OP has ideas that would affect this

 

[huskyboy]

The most effective way to eliminate the problem is a complete redesign like the 550mk2 and 572xp. Those two saws are quite heat resistant compared to the 562 and mk1 550... and it’s easy to see why when you take them apart. Who knows when husqvarna will finally redesign the 562 though... that’s the 64,000$ question.

 

[huskihl]

357 ftw

 

[jacob j.]

357 and mullet ftw

Fixded