Husqvarna 350 will not start

[adw]

5 hours ago, hesslemount said:

Tried restarting 560 after 30 minutes turned off and nothing. Absolute dead pull.

Is this an early 560? Is the fuel tank breather fed via a tube into the air filter housing? Is the fuel hose clipped into the cylinder partition wall, do you have the additional slot in the top cover, these things were issues on the early saws, do you have the orange frame air filter? If you have any of the above we can advise how to update them.

[hesslemount]

53 minutes ago, adw said:

Is this an early 560? Is the fuel tank breather fed via a tube into the air filter housing? Is the fuel hose clipped into the cylinder partition wall, do you have the additional slot in the top cover, these things were issues on the early saws, do you have the orange frame air filter? If you have any of the above we can advise how to update them.

Orange frame air filter yes

[adw]

The orange frame filter is down to 25 micron, even though it may look clean they block very easily, auto tune then leans the mixture to compensate increasing heat, there is a kit to update to the mark11 air filter.

[hesslemount]

10 hours ago, adw said:

The orange frame filter is down to 25 micron, even though it may look clean they block very easily, auto tune then leans the mixture to compensate increasing heat, there is a kit to update to the mark11 air filter.

Could you send me a link for this kit please. I guess the saw is 7-9 years old now. The saw is fantastic like the 562 I bought same time; but the 560 won’t restart but works amazing when it’s running.

[spudulike]

When you pull the saw over without using the decomp valve, does it have good compression? 7-9 years is a relatively long life by modern standards. It may be the breather or air filter...both are pretty common issues and hope ADW is correct on this. 

Try lifting the 562 and 560 together on the pull start and see which one falls to earth the fastest.

[hesslemount]

On 12/10/2022 at 19:54, spudulike said:

When you pull the saw over without using the decomp valve, does it have good compression? 7-9 years is a relatively long life by modern standards. It may be the breather or air filter...both are pretty common issues and hope ADW is correct on this. 

Try lifting the 562 and 560 together on the pull start and see which one falls to earth the fastest.

Both have the same compression. Saw works like a dream all day and if never switched off will work for fun. Great saw. But after using 30 minutes plus and turning off won’t restart until 2 hours have expired and then it starts up like a brand new saw 

[adw]

This sounds more like vapour lock, are you using old stored fuel? is the saw exceeding its max rpm, should be 12500, is the winter flap open in the top cover? are all the air vents in the starter cover clear? try buying fuel from else wear, is it a later saw with a fuel purge bulb? if yes work the bulb to pull cooler fuel through the carb.

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[adw]

Sorry got mixed up with the original 350 post, 

[spudulike]

Very difficult to tell. Do you use the decomp valve? If you do...don't and see if it helps. 

My thinking is: -

1) Compression may have backed off and being hot makes it worse...hence the decomp question above.

2) The orange air filter is blocked and the AT unit is leaning down the mix to compensate for the air filter condition making it difficult to start....this comes back to ADWs unanswered question about orange air filters.

3) At 7 years, the carb pump gasket may have pierced pump flaps, the gauze strainer may be partially blocked or the metering diaphragm may be saggy causing issues.

It is worth changing the spark plug as it is easy, cheap and at least it takes the plug off the list of unknowns.

[lurch_917]

or is it just as simple as vapor locking due to heat ? are you using the hot start method ie engage choke take you choke off without touching the trigger then give it a pull or two.