Two 550's, neither firing

[Acerforestry]

This has to be just lousy coincidence but in the woods yesterday, my main use 550 that's still under warranty decided to suddenly just not start, then back up model acted the same 2 hours later. Fuel appears fine and correctly mixed, filters not blocked, plugs ok - strangely, they won't even pop on full choke with easy start? Unit still under warranty has been somewhat hammered on chestnut coppice but is still only 4 months old, and it blew a ring after just 12 hours use and was then rebuilt. Great little saws when running right, but I'm thinking of another brand now, possibly time to get an Echo ground saw. Any ideas what may be causing the fuel starvation if not the tank filter

[adw]

I fear they may have seized and nipped the ring in, are you absolutely sure about the fuel mix??

[gdh]

Did you check it was 2 stroke oil you put in to the mix?

 

When someone put straight petrol in my 357 it seized completely rather than fail, the only similar problem I've had was with a perished pipe on a brand new saw.

 

I think the 550/60s are the best all round saw in every way.... except reliability. 

[Echo]

If it did not fire on starting fluid, then it may not be fuel related.

Did you try flooding the saw, keep the choke on and see if after about Ten pulls if the plug is wet, it it is then you are getting fuel. 

The obvious, is there a spark at the plug, if not, then it's not starting.

The bad news, if Two saws do the same thing, and they had the same fuel used in both, then I would question the fuel, if it was straight petrol it would be high on the list of possible reasons your saws started acting up at the same time, may be take the muffler off the oldest saw that is our of warranty, and have a look for the dreaded scoring, even look in the plug hole for scoring with a good bright light, but muffler off is better.

If they are scored, then you could still build them again, way cheaper than replacing Two saws.

 

Echo are definitely a reliable saw, not as powerful but they are dependable. I have had Two CS 501SX saws, with  16 inch bars, and they have been trouble free, I plugged the hole in the case where the idle screw gets adjusted to keep out dust, and put Vaseline on the o ring that the air filter sits over, and that was all I needed to do, they are easily muffler modded too.

The Stihl 261 is another option, I seem to read less problems with them, they were reported to have soft cranks, but I hear nothing about this for a good while now.

 

Edited March 31, 2019 by Echo

[Ian C]

I had a 550 go pop as it was ticking over!

Echo are v good, basic old skool but reliable.

 

[Acerforestry]

Thanks for replies, i should have mentioned that fuel mixes were from two different cans, both defo 50-1 Husqvarna top of the line 2 stroke, so it doesn't make sense that they have seized. Looks like warranty saw will have to go back monday to find the cause so i will put a post on confirming what has occurred

[Ian C]

2 hours ago, Acerforestry said:

Thanks for replies, i should have mentioned that fuel mixes were from two different cans, both defo 50-1 Husqvarna top of the line 2 stroke, so it doesn't make sense that they have seized. Looks like warranty saw will have to go back monday to find the cause so i will put a post on confirming what has occurred

In my opinion the auto tune stuff just runs too lean to last any length of time. 

[gary112]

Got a 2013 550xp never had a days trouble still a good saw

[Khriss]

After losing hope in the new Husqvarna ( love my old ones) I found the exhaust gasket lifted on my 560 xpg  initiated a seize on exhaust port face of piston- after 4 months arbor work. If that's a useful hint. K

[Echo]

3 hours ago, Acerforestry said:

Thanks for replies, i should have mentioned that fuel mixes were from two different cans, both defo 50-1 Husqvarna top of the line 2 stroke, so it doesn't make sense that they have seized. Looks like warranty saw will have to go back monday to find the cause so i will put a post on confirming what has occurred

Thats good to know, hopefully no ceasures. Really odd how they both won't start, but if I remember hot starts were an issue with these saws, and the solutions varied, some gave one pump of the primer with the red leaver in the position it auto returns to when you stop, others had to choke for a pull or two, then go to run position, others had to let them cool off, others had to go into the carb and adjust the metering level, others had to do away with the primer circuit, and what worked for one did not work for another. These saws simply could not stay cool enough when under a heavy load, hot weather made matter considerably worse, I think the MK2 550 will have addressed this. Another thing, 50:1 is not a lot of oil in an Atotune or any saw for that matter, given they run hot supports my theory that the Autotune does not put in enough fuel to cool them a bit, thus it does not put in enough oil either, so things spiral into the hot zone.

I hope its something simple like a hot start issue.