455 rancher. Is primer bulb necessary

[jakethesnake]

What exactly does this bulb even do? Do I need it at all? I use this saw just some. Enough to keep it running. Hate letting anything set too long. Saw starts fine runs fine. Tune stays put. It just barely weaps gas out when running. The bulb is actually cracked for sure. I likely have a bulb laying around
Can I just cap a fuel line ?
Why do they even use those things.

 

[a. palmer jr.]

I use the primer bulb on my Lawn Boy mower. Other than that I usually remove the primer bulb. What it does is just put fresh fuel into the carb and discharges the fuel that was in the carburetor back into the tank. If you remove the bulb you have to block off the openings where the lines went.

 

[RIDE-RED 350r]

I too have wondered why some small two-stroke carbs have primers and some don't. What's the line that is crossed where it's determined a primer is needed and why? 346OE: no primer. 346NE: primer.

 

[a. palmer jr.]

I'm not sure there is a line, some cheap saws have them and some not so cheap saws have them. My 346 doesn't have one either but I have a couple of cheap plastic Poulan saws that have one..a few years back none of them had one..

 

[jakethesnake]

Wish they still didn’t have them

 

[RIDE-RED 350r]

Another thing I have noticed regarding the 346's... The OE that does not have a primer came with a Walbro carb.. (at least the OE's I have seen) and NE's have a Zama.. Pump generally stronger in a Walbro than the Zama??

But then again, Zama carbs went into 357/9 at one point and they never had a primer that I'm aware of.

Paging @tree monkey Can you shed some light on this? I recall you are the man who figured out the HDA199 issues and saved a bunch of us from tossing an otherwise good carb.

 

[jakethesnake]

455 isn’t the most expensive or best saw on the market by far but it’s a hella lot better than some say they are. This one doesn’t owe anyone anything.
That bulb is one thing that I really hate. If I put it back the plan will be never push it again.

 

[jakethesnake]

Another thing I have noticed regarding the 346's... The OE that does not have a primer came with a Walbro carb.. (at least the OE's I have seen) and NE's have a Zama.. Pump generally stronger in a Walbro than the Zama??

But then again, Zama carbs went into 357/9 at one point and they never had a primer that I'm aware of.

Paging @tree monkey Can you shed some light on this? I recall you are the man who figured out the HDA199 issues and saved a bunch of us from tossing an otherwise good carb.

I’m gonna have to check my 346s. I thought one had a zama. I know the other is a walboro.

 

[RIDE-RED 350r]

I’m gonna have to check my 346s. I thought one had a zama. I know the other is a walboro.

You have both OE and NE?

 

[jakethesnake]

You have both OE and NE?

Nah both oe. No bulbs. I think all the ne has bulbs

 

[jakethesnake]

And one needs a new crank... that looks like a project. I’ve been putting that one off

 

[fearofpavement]

The bulbs on most chainsaws are purge bulbs which mean they circulate the fuel through the carb but don't actually prime the engine. The same looking bulb on many push lawnmowers actually is a primer bulb.
Whether the bulb is important or not for operation depends on the saw. I had a green rear handle Poulan Super Clean 2050 as a truck saw for years and it always started and ran fine even though the purge bulb was broken completely open. Some saws will suck air if the bulb is cracked.
For a couple bucks, just replace it rather than wonder about it. I usually stock several sizes along with my carb kits but none of my line up saws use one. My string trimmer does though.

To route the lines on a typical Poulan, keep in mind that the fuel goes from the tank filter into the carb, from the carb to the bulb, from the bulb back into the tank. This is important to know as usually the lines are in half inch bits and pieces when they come in. (and the fuel filter will be loose in the tank along with a duck bill...)

 

[sixonetonoffun]

My old Stihl 011 would benefit from a true primer. That has to be the worst choke design ever.

 

[Stump Shot]

I use the bulb on my 460 Rancher, just saves a couple pulls to prime the carburetor before it will start up and run. If I do everything just right, I've been able to get one start pulls out of it, if not, two, at the very worst, three, never more than that. So I guess that makes me a fan of the primer bulb. On saws without I usually pull over real slow a few times to prime up the carburetor before attempting to start. Saves on my poor old arm that is falling apart. Lol

 

[jakethesnake]

I was pushing on that one when it cracked. Makes me wonder if I just never push it ever again will it just last forever

 

[sunfish]

The bulb makes easier/quicker start ups when cold or have been sitting a long time. I actually like em, but only have em on one 346NE & a 562xp. Have half a dozen other saws that don't.

 

[Stump Shot]

I was pushing on that one when it cracked. Makes me wonder if I just never push it ever again will it just last forever

Which reminds me my Stihl BR600 blower is like that, but as long as it is warm it will start up no problem. Always something to fix!

 

[jakethesnake]

Which reminds me my Stihl BR600 blower is like that, but as long as it is warm it will start up no problem. Always something to fix!

You got that right

 

[Wood Doctor]

Which reminds me my Stihl BR600 blower is like that, but as long as it is warm it will start up no problem. Always something to fix!

There is one thing that happens to me on a regular basis. If I do not replace an owner's primer bulb because I think it's OK for another year or so, in about a month the saw or leaf blower comes back with a cracked, chewed up bulb all ready for me to replace.

And, most would agree that ethanol fuel does a number on the bulbs.

 

[fearofpavement]

My old Stihl 011 would benefit from a true primer. That has to be the worst choke design ever.

I just ran across a baggie full of 011 bits today while looking for something else.