Husqvarna 550xp pop up

[tree monkey]

Nope, it idles just fine. No sucking of air back into the wetside. Blocking off the primer bulb fixed my problem.

As I said, the primer bulb pushed fuel into the wetside through a separate orifice. The check valve in the main discharge nozzle prevents air flow BACK into the wetside. It allows fuel to go into the engine.

I've never seen a 550 carb, so I don't know how it is primed. However, if I've learned anything about saw carbs, is that I never assume anything about the circuits - there are so many different circuits.

so you have 2 fuel filters in the tank? one for the carb and one for the primer?

 

[Stump Shot]

Huh?

Not plain enough?
There are two basic "heat" associated problems as stated before in this thread.
One being the saw shut off and the warmth from the motor soaks into the carb box causing vapor lock.
The other being an operator issue with ham hands and a dull chain, the heat from the bar melting the PTO side bearing retainer allowing the ball bearing free to roam to one side, taking out the seal leading to a blown top end if not caught in time.
My personal thoughts on this are that it stems from the compactness of the 550's design, there's very little room under the top cover to allow heat to dissipate when the saw is turned off, this same compactness of the crankcase leaves little room for an overheated bar to be soaked away. I say this looking at A, what has happened and B what is happening with the new 550 coming soon from Husqvarna. It took the svelte sleek saw and made it more robust to address these very issues.
I don't see myself having issue with either of these two problems with my "old" style 550, especially so in winter time.
More betterer?


Edit: the motor does not "run hot".

 

[tree monkey]

Nope, it idles just fine. No sucking of air back into the wetside. Blocking off the primer bulb fixed my problem.

As I said, the primer bulb pushed fuel into the wetside through a separate orifice. The check valve in the main discharge nozzle prevents air flow BACK into the wetside. It allows fuel to go into the engine.

I've never seen a 550 carb, so I don't know how it is primed. However, if I've learned anything about saw carbs, is that I never assume anything about the circuits - there are so many different circuits.

it can leak and still idle, that depends on how bad it leaks.

have you tested the nozzle?

 

[wcorey]

I went out to the shop and poked around in a 450 just to confirm.
Probably late to the party by this time but since I typed it all out...

The primer pulls fuel through the carb, starting at the fuel inlet on the pump side, through an outlet on the metering side and back to the tank on the primer return line.

If the primer hoses were installed backwards, pushing fuel into the metering side, the return line would then act as a pickup and it would need another filter in the tank. Would also have to go to the bottom of the tank, it doesn't.
If it were set up to pull fuel, it would then push fuel out the jets and never make it to the pump side or back to the tank.

If the tank is pressurized, it cant (or at least shouldn't) get back through the primer as the valving there is in the opposite direction, acting as a check valve.
And yes, if the main jet check is leaking the primer will suck air through it...

 

[Terry Syd]

so you have 2 fuel filters in the tank? one for the carb and one for the primer?

Nope, it appears that they may have just swapped the lines on the bulb. My frustration with the saw was fixed by plugging the line to the bulb. That seems to be the easiest answer to what happened.

 

[tree monkey]

Nope, it appears that they may have just swapped the lines on the bulb. My frustration with the saw was fixed by plugging the line to the bulb. That seems to be the easiest answer to what happened.

it's as good of a fix as any really.

I assume it has a zama carb?

 

[Dub11]

Not plain enough?
There are two basic "heat" associated problems as stated before in this thread.
One being the saw shut off and the warmth from the motor soaks into the carb box causing vapor lock.
The other being an operator issue with ham hands and a dull chain, the heat from the bar melting the PTO side bearing retainer allowing the ball bearing free to roam to one side, taking out the seal leading to a blown top end if not caught in time.
My personal thoughts on this are that it stems from the compactness of the 550's design, there's very little room under the top cover to allow heat to dissipate when the saw is turned off, this same compactness of the crankcase leaves little room for an overheated bar to be soaked away. I say this looking at A, what has happened and B what is happening with the new 550 coming soon from Husqvarna. It took the svelte sleek saw and made it more robust to address these very issues.
I don't see myself having issue with either of these two problems with my "old" style 550, especially so in winter time.
More betterer?


Edit: the motor does not "run hot".

TL,DR

 

[Stump Shot]

TL,DR

Then don't ask and I won't tell.

 

[Terry Syd]

I assume it has a zama carb?

Yep, I pulled the stock carb off (11mm) and put on a carb from a 570 (13.5mm). I had to build a stop for the choke as it rotated the opposite way. Dropped the metering spring pre-load to ramp the fuel in faster with the bigger carb and it works great.

I just went out to the shed and removed the plug in the carb hose and swapped sides on the bulb. Looking at the bulb I remember making a repair to it years ago, I had to epoxy it up. Anyway, the saw primed and started, I'll have to use it in the field and see how it goes. If the primer gives me any trouble, I've still got that plug.

 

[1990Husky262]

sometimes the check valve in the primmer fails and can allow fuel/pressure to back flow and cause flooding issues

 

[Barneyrb]

Dang, this thread reminds me of threads past with different players but basically the same end result. Some things never change.

 

[USMC615]

Made it to page 8 on a break and had to put the brakes on. I'll try and finish this *s-wordt sandwich later. But I juss' gots to axe...

...what kinda damn backwoods, hemp burning, meth-merized, goat roping, redneck, hillbilly, Deliverance luvin', Hee-Haw and Green Acres watchin' *s-wordfest did this turn into? Lmao on most of what I read up to page 8!

 

[Czed]

Made it to page 8 on a break and had to put the brakes on. I'll try and finish this *s-wordt sandwich later. But I juss' gots to axe...

...what kinda damn backwoods, hemp burning, meth-merized, goat roping, redneck, hillbilly, Deliverance luvin', Hee-Haw and Green Acres watchin' *s-wordfest did this turn in to? Lmao on most of what I read up to page 8!

You must not work on saws much
It's always like this.

 

[JohnnyBlade]

Made it to page 8 on a break and had to put the brakes on. I'll try and finish this *s-wordt sandwich later. But I juss' gots to axe...

...what kinda damn backwoods, hemp burning, meth-merized, goat roping, redneck, hillbilly, Deliverance luvin', Hee-Haw and Green Acres watchin' *s-wordfest did this turn in to? Lmao on most of what I read up to page 8!

This made me laugh more that the last 21 pages u havent lived life till u try a lil goat roping

 

[Terry Syd]

I'm still waiting for Wayne to get back to us about the finger and farting...

 

[USMC615]

You must not work on saws much
It's always like this.

No, it's not always like this...maybe over on AssSite it still is. I'm very familiar with that group of clowns as I was a member there for a couple of years, some years ago, before getting the boot (you can say I was a little too rough and rowdy with the Pol/Rel girls over there).

Now don't nobody spoil it for me...I haven't read into this thread far enough to see if 'Captain 550XP Pop-Up' got his walking papers or not!

 

[Stump Shot]

Dang, this thread reminds me of threads past with different players but basically the same end result. Some things never change.

Seeing that this thread hasn't ended and the op still around and available to post is a much better ending than most I'd think.

 

[angelo c]

No, it's not always like this...maybe over on AssSite it still is. I'm very familiar with that group of clowns as I was a member there for a couple of years, some years ago, before getting the boot (you can say I was a little too rough and rowdy with the Pol/Rel girls over there).

Now don't nobody spoil it for me...I haven't read into this thread far enough to see if 'Captain 550XP Pop-Up' got his walking papers or not!

Walkin papers ?
Huh.... we got him a new "foredom" and he's a site mod and a full time builder now... so you better watch that "liberal progressive bs all you 'Marine' type guys always profess....over on the Politics site... ...




yes...


I'm kidding...

 

[GCJenks204]

I'm still waiting for Wayne to get back to us about the finger and farting...

@Dub11 ?? Going to test results at work tonight?

 

[Terry Syd]

If he tells us it makes you burp, I think I'll be nauseous.