Husqvarna 550xp pop up

[Simondo]

Not on my 450, it pumped fuel INTO the carb. I don't know how the 550 is set up, perhaps someone could check.

That is unusual ...

 

[RIDE-RED 350r]

Hooked up wrong??

 

[angelo c]

The primer bulb circuit doesn't go through the metering valve, it goes directly into the wetside of the carb (at least it did on the 450).

If the primer bulb has a simple flapper valve, then the fuel can push past it into the carb.

terry, does releasing the pressure on the tank release pressure on the line ? ie crack the cap open and then restart. Mine is not the "classic" husky hot restart type of fail but it feels like its "flooded" as you describe. great little saw but funky on some restarts ...

 

[huskyboy]

A 550/562 will not flood the motor with the purge bulb. There is even a little diagram on the saw explaining restart process, involving pumping the purge bulb up to 6 times. The problem is vapor lock from the carb/fuel line getting too hot. The bulb won’t fill with fuel when this happens. Especially on older versions without the top cover cutout, older fuel line routing setup and tank vent line that went into the carb box. I still think gutting the muffler made the most difference for me...

 

[Terry Syd]

does releasing the pressure on the tank release pressure on the line ? ie crack the cap open and then restart.

I tried that on mine, but if the saw is already flooded then doing it just before a restart wouldn't help.

 

[tree monkey]

I saw this thread and thought it might have an interesting discussion on a pop-up for a Husky strato - then I thought I had accidentally ended up on AS.

So, I read through the entire thread. I'm still waiting for Wayne (Dub11) to get back to us about the finger and farting. Like, what happens? Does it push the finger out? Does it make squeaky noises?

Now about the hard starting issue while hot. Maybe I have the answer.

My Husky 450 almost drove me nuts with the same hard re-starting issue. I finally figured it out - and when you guys mentioned the primer bulb in this thread, it may be the same problem I had.

On the 450 the primer bulb was fed directly from the fuel tank. When you shut off and the tank gets hot it pressurizes the fuel tank. Fuel is pushed up through the primer bulb and into the carb.

The valves on the primer bulb only go one way - to the carb. The inlet to the carb from the bulb is not controlled by a valve like the metering valve, it is a straight shot into the carb. The fuel keeps flowing and the only place it can go is into the engine. The engine gets flooded.

I blocked off the primer bulb and no more difficult re-starting problems.

i'll bet 100 bucks your high speed nozzle leaks

 

[tree monkey]

infact I know it leaks if your getting air in the bulb

 

[Terry Syd]

Mine is not the "classic" husky hot restart type of fail but it feels like its "flooded" as you describe. great little saw but funky on some restarts ...

Here's something you can try. Just block off the line going to the primer bulb. I stuck a piece of nail in mine. If that fixes the problem....

 

[tree monkey]

the primer can't work without a check valve, the high speed nozzle is the check valve

 

[hseII]

I sold my 288 [emoji848]

That 066 will make the 288 a weak, distant memory.


Sent from my iPhone using Jon1212 Pro

 

[hseII]

Battlefield V on the PC

Oregon Trail, sucker.

I haven’t played those since I got thisinterry.
(Dysentery)


Sent from my iPhone using Jon1212 Pro

 

[hseII]

And am I wrong to take an eductaed guess that EPA regulations against fuel evaporation into the atmoshpere has given us tank vents that are check valved? Meaning: air can come into the tank as fuel is consumed, but the tank is not allowed to "breathe" if pressure starts to build, for example when the saw is left sitting in direct sunlight or as you stated, the tank gets warm rapidly...

I can see fuel being force fed into a carb and engine with a situation like that.

2 points for being warm with pressure & also being force fed with a situation.


Sent from my iPhone using Jon1212 Pro

 

[Terry Syd]

i'll bet 100 bucks your high speed nozzle leaks

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.

 

[hseII]

Hooked up wrong??

Those Swedish Q.C. Hacks!


Sent from my iPhone using Jon1212 Pro

 

[angelo c]

Here's something you can try. Just block off the line going to the primer bulb. I stuck a piece of nail in mine. If that fixes the problem....

Cant get cheaper or easier to try that

 

[hseII]

infact I know it leaks if your getting air in the bulb

No Bubbles, No Troubles.

Applicable here too.

How you feeling Pawpaw?


Sent from my iPhone using Jon1212 Pro

 

[angelo c]

So what has happened in our little thread. Went from a chit show to pretty darn valuable in a few seconds....so the moral of the story is....hang around long enough and you might just learn sumptin.

 

[Terry Syd]

Those Swedish Q.C. Hacks!

Yeah, maybe I got a saw that was put together on a Friday afternoon!

 

[hseII]

Yeah, maybe I got a saw that was put together on a Friday afternoon!

Monday too! You know how those loose Europeans are.


Sent from my iPhone using Jon1212 Pro

 

[tree monkey]

the primer can't work without a check valve, the high speed nozzle is the check valve

I need to rephrase this

there is a vale in the primer on the intake side, carb side.
the primer draws fuel through the carb and pushes it to the tank. it won't do anything if the check valve is open.
if the nozzle is leaking the primer draws air instead on fuel.

when you press the primer you can see the metering diaphragm get pulled in to open the needle to let fuel in.

if you hear a squeak in the carb, it's likely the air going in the nozzle