550 XP hot starts/ performance

[born to hunt]

Thanks to all the folks who helped out last time with advice on new saw. I landed on a 550 XP, so now I have a 346 xp and the 550 with the Auto tune.

First time out today...550 report: started like a dream and this saw was outstanding. Storms took down a 70 year old hackberry and it cut like I've never seen a 50 cc saw cut...UNTIL...

It came time to hot start. I pulled and pulled and it started and stopped and never ran worth a crap until i let it completely cool. Then it ran like a dream again.

I'm feeling like I just bought the best one -time use saw ever...Help?

 

[w8ye]

I have a 545 and a 550 and have never had any hot start problems.

For a hot start, I put the choke "ON" and then shut it "OFF" and without touching the trigger I push in the compression release and give the cord a yank for all I'm worth and the saw starts right up - time and again.

This action of putting the choke on and off leaves the throttle on fast idle.

 

[MCW]

I honestly think some of the hot start issues are related to the user and not the saw as mentioned by old mate w8ye above. I experienced the same problems early with my 550XP and assumed it was a saw problem but later on realised that they just have a slightly different starting sequence than many other saws when warm.
I have found though that after some use and sitting for a while you can try to start them with no choke and they won't go - you then try the choke and it's like you've flooded it. The fast idle setting is the middle ground you need to use.
The above starting procedure works well

 

[wyk]

I have a 545 and a 550 and have never had any hot start problems.

For a hot start, I put the choke "ON" and then shut it "OFF" and without touching the trigger I push in the compression release and give the cord a yank for all I'm worth and the saw starts right up - time and again.

This action of putting the choke on and off leaves the throttle on fast idle.

One of the reasons I prefer the husky controls.

 

[MCW]

One of the reasons I prefer the husky controls.

Hey I agree and as you know I'm a Husky fan but at least the M-Tronic saws will start and continue to idle on their "choke" setting unlike the Autotune.

 

[sunfish]

Some of these new saws like fast idle for warm starts, Purge bulb helps too. Seems like after awhile they settle down and start/run better. My 562xp acted weird at first, but after I learned how to start it (new controls and AT), it has become my easiest starting saw.

 

[MarkEagleUSA]

I honestly think some of the hot start issues are related to the user and not the saw as mentioned by old mate w8ye above. I experienced the same problems early with my 550XP and assumed it was a saw problem but later on realised that they just have a slightly different starting sequence than many other saws when warm.

Here's my un-educated guess on the situation.

In some video I watched it was explained that the carb has little solenoids that pump the gas. When attempting to start the saw (hot or cold), the AutoTune "brain" has no way of knowing anything since there's no power until the saw is running. At start-up, my guess is the solenoids pump fast enough to make sure fuel gets into the saw. In a warm start scenario, without the fast idle set via the choke lever, there's no enough air and the saw floods itself out.

I also think that the 550 (and 562) wants the decomp valve enabled as well so that you can get a smooth pull on the cord giving the engine the best chance of starting.

It's definitely finicky, but following the prescribed warm-start procedure does seem to work (almost) all of the time.

 

[born to hunt]

Wow...

I have not tried that starting sequence. My other option is to leave it running all year long...

Thanks for the help....I will try this evening. Anyone recommend the best chain for that outfit? I have a 18" bar with a .325 72 link chain. Cutting firewood and storm damaged trees.

 

[MCW]

Wow...

I have not tried that starting sequence. My other option is to leave it running all year long...

Thanks for the help....I will try this evening. Anyone recommend the best chain for that outfit? I have a 18" bar with a .325 72 link chain. Cutting firewood and storm damaged trees.

I'd look at semi chisel personally but any of the full chisel chains will be fun in green, clean timber. If there is any dirty wood go semi chisel for sure.

 

[born to hunt]

MCW and the rest: apparently the intellectual horsepower on this site has outclassed my supposed knowledge of how to start a chain saw. Your advice worked to perfection on the hot start with the 550 XP. Thanks for taking the time to help out...hope i can return the favor someday!

 

[MarkEagleUSA]

MCW and the rest: apparently the intellectual horsepower on this site has outclassed my supposed knowledge of how to start a chain saw. Your advice worked to perfection on the hot start with the 550 XP. Thanks for taking the time to help out...hope i can return the favor someday!

Husqvarna (and/or the dealer) needs to do a better job of making sure the starting procedures are known to the users instead of burying them on page 20 of the manual that most people aren't going to read. :msp_unsure:

 

[DexterDay]

One of the reasons I prefer the husky controls.

When a Stihl is choked and turned off, it is at Fast idle also??! All of mine are. Both new and old. This is not just designated for Husq. Even Poulans and Craftsmans do this. High idle when choke is turned off (don't touch throttle) is par for the course.

My BIL 562xp was a mess to Hot start. It has now been at the dealer for a month...... Will start, idle, then as soon as throttle is touched? Dies. They have tried everything at the dealer. They are now trying a whole new computer after throwing numerous parts at it... Hoping for a new saw after all the troubles.

 

[born to hunt]

F

When a Stihl is choked and turned off, it is at Fast idle also??! All of mine are. Both new and old. This is not just designated for Husq. Even Poulans and Craftsmans do this. High idle when choke is turned off (don't touch throttle) is par for the course.

My BIL 562xp was a mess to Hot start. It has now been at the dealer for a month...... Will start, idle, then as soon as throttle is touched? Dies. They have tried everything at the dealer. They are now trying a whole new computer after throwing numerous parts at it... Hoping for a new saw after all the troubles.

That was exactly what my 550 xp was doing. Tried to go easy on the throttle and feather it up. No use. Tonight, I used the aforementioned sequence and let it run at high idle for about 15 seconds before throttling up. Seemed to work good. IMO that's a strange series of steps to have to follow...but it is what it is.

 

[MCW]

F

That was exactly what my 550 xp was doing. Tried to go easy on the throttle and feather it up. No use. Tonight, I used the aforementioned sequence and let it run at high idle for about 15 seconds before throttling up. Seemed to work good. IMO that's a strange series of steps to have to follow...but it is what it is.

Yep this starting sequence did my head in too

 

[sunfish]

Most of these treads about the new AT saws end this way.

Also a few of my saws need to warm up just a bit before one goes hittin the throttle...

 

[SawTroll]

I honestly think some of the hot start issues are related to the user and not the saw as mentioned by old mate w8ye above. I experienced the same problems early with my 550XP and assumed it was a saw problem but later on realised that they just have a slightly different starting sequence than many other saws when warm. .....

I am quite sure you are right about that! :agree2:


Taking a look in the operator manual sometimes pays off (not just with these saws)......:biggrinbounce2:

 

[MarkEagleUSA]

Maybe someone who knows the AT system a little better will chime in here, but I think that AT is trying to do a lot of stuff at startup and as a result probably errs on the safe side by allowing a very rich mixture. Until the saw is running and can sense speed, load, and temp, it can only make best guesses. Obviously, the fast-idle setting for warm starts makes sure that air (and hopefully enough of it) gets introduced to the carb and engine so that all that fuel can be burned.

Like I said, the AT starting procedures need to be clearly spelled out to new owners. Maybe Husqvarna should include some sort of laminated card that shows the instructions. Certainly, every dealer that sells an AT saw needs to communicate the proper starting techniques every time they deliver one.

Luckily for me, I saw (and heeded) the warnings about the warm-start procedures here on AS and was ready when my 562 and 550 AT's arrived (both were bought mail-order).

 

[hamish]

Husqvarna (and/or the dealer) needs to do a better job of making sure the starting procedures are known to the users instead of burying them on page 20 of the manual that most people aren't going to read. :msp_unsure:

Geez even when Husqvarna had the starting sequence in pictures on the saws people were too lazy to look at them. The only users that pay attention to detail and what they are told by the dealer are woman.They never come into the shop whinning like little girls that there xp piece of junk wont start.

Its only men, that know it all and lack the ability to RTFM.

 

[w8ye]

I have a 550XP and a 545. The two chainsaws are a lot alike. Differences - Sliver paint - full circle crank - 13K vrs 14K coil - and port timing?

Anyway, I got the 545 out today to shorten up (firewood size) a bunch of cut-off limbs. They were oak, silver maple, and walnut.

Many hot starts after stopping to sort the wood out and stack the cut pieces.

This thread had me worried . . .

The 545 started up first pull for every hot start. I even ran it out of gas once and restarted easily. But I made sure that I had the air purged from the carburetor before trying to start the chainsaw.

Did a lot of "HOT STARTS" - no problem - one pull hot starts. Every time, - I put the choke "ON" then "OFF" to set the fast idle then pushed in the compression release. "ONE PULL" and she was going again.

However yesterday, I saw a kid working for Asplundh across the street try to start the company 372XT ground saw cold. He missed the burp and flooded it. Then the white hat had to pull and pull to get it started.

 

[Marvinlee]

Thanks for very useful tip!

I have a 545 and a 550 and have never had any hot start problems.

For a hot start, I put the choke "ON" and then shut it "OFF" and without touching the trigger I push in the compression release and give the cord a yank for all I'm worth and the saw starts right up - time and again.

This action of putting the choke on and off leaves the throttle on fast idle.

Thanks. That is very handy to know. I've had a problem with the engine dying after starting, before I have time to put my fingers on the throttle.