My 562XP has a bad bog

[afleetcommand]

Be curious to put that carb on CST and find out the history & last fuel settings.

 

[huskihl]

Any more discoveries on this subject? I've got one here with an EL46 on it with the same bog. If it idles for more than 5 seconds it bogs with a puff of black smoke when I nut it.

 

[Moparmyway]

Does the puff of black happen before the bog or after ?

 

[huskihl]

Does the puff of black happen before the bog or after ?

Hard to tell. Pull the trigger, 1/4 second hesitation, puff of smoke gets blown out as it revs up. Cleans out instantly like it never happened.

It's not loading up at idle, if that's what you're thinking. It doesn't load up until you pull the trigger

 

[Moparmyway]

Hard to tell. Pull the trigger, 1/4 second hesitation, puff of smoke gets blown out as it revs up. Cleans out instantly like it never happened.

It's not loading up at idle, if that's what you're thinking. It doesn't load up until you pull the trigger

Welp Kev, here goes .................
As far as the idle, I dont believe that there is any problem there
I believe that you have a lean condition, the autotune is trying to compensate for it by opening the fuel valve, recovering, and belches out a burp of black smoke while it pulls back on fuel, from recovering from a lean condition

These computer controlled carbs are fast, but please consider what happens FIRST

 

[Chainsaw Jim]

Hard to tell. Pull the trigger, 1/4 second hesitation, puff of smoke gets blown out as it revs up. Cleans out instantly like it never happened.

It's not loading up at idle, if that's what you're thinking. It doesn't load up until you pull the trigger

Does it do the same thing if you run it without the air filter?

 

[huskihl]

Does it do the same thing if you run it without the air filter?

Hmm. Never tried that. It's a mesh style filter

 

[huskihl]

I'm thinking now it's actually a lean bog, but the AT over compensates instantly and floods it a tiny bit

 

[huskyboy]

I'm thinking now it's actually a lean bog, but the AT over compensates instantly and floods it a tiny bit

That’s what I’m guessing. A reflash gets it fresh slate to start over so it’s not thinking it’s a airleak is another guess. However the el46 has been a problem carb so I’ve heard.

 

[huskihl]

That’s what I’m guessing and a reflash gets it fresh slate to start over so it’s not thinking it’s a airleak is another guess. However the el46 has been a problem carb so I’ve heard.

I've found the same thing from reading up on here and talking with others. The effects of the re-flash may possibly only last a month or 2 before it reverts, also. A new EL48 seems to be the fix

 

[huskyboy]

I wonder how the early el44 carb saws ran or if they were better than the 46?

 

[Onan18]

I wonder how the early el44 carb saws ran or if they were better than the 46?

The 44 was really a better carb than the 46 Mason, every one I have ever had has been flawless.

 

[huskyboy]

The 44 was really a better carb than the 46 Mason, every one I have ever had has been flawless.

What happened to don’t fix it if it ain’t broke? Lol. I guess they wanted to try improve it?

 

[Moparmyway]

I've found the same thing from reading up on here and talking with others. The effects of the re-flash may possibly only last a month or 2 before it reverts, also. A new EL48 seems to be the fix

I’ll betcha that lean condition can be fixxed without having to change carbs

 

[huskihl]

I’ll betcha that lean condition can be fixxed without having to change carbs

I'm sure it can

 

[TheShopBend]

Hey I have a couple T540XP saws I'm working on that exhibit the same symptoms as the 562 the thread was started for. I've found they are low on compression but even when I have rebuilt the cylinders the comp stays way low at 94 psi hot and 103 cold. Two different saws one with new cylinder and piston the other just a piston and ring assy. The complete rebuild saw does not run can't even get it to start now that the new parts are on. The other saw with the oem cyl and a new piston assy runs like a top but shares the exact same comp numbers. And to add another level of head scratching I pulled a brand new mk2 off the display shelf and it makes 106 psi cold. My main questions however are as follows. What is the deal with the 540 and low comp. Are they just not seated yet and need more run time? I'm located about 3600 feet above sea level do compression numbers show lower at high alt or is that a myth. And last question is how much does compression usually increase after the rings have had time to seat, like is it usually a 10 psi increase, 20, or are you lucky to get 5 psi increase? I feel like i should know that last one being a technician and all but I have never had a reason to check and make sure new parts are making more compression.

Thanks for reading that whole thing, The Shop