Off topic: Explain why small carbs will not prime after storage.

[Fordiesel69 226]

This happens to a lot of weed wackers, chainsaws, blowers, etc with Zama, Walbro, carbs.  After storage the primer bulb will not draw up fuel.  It is not damaged either.  So my solution is to remove carb, loosen the diafram screws and the other screws that hold it together.  Then submerge the entire thing in a jar of gas and oil mix.  The next day remove and tighten all screws, then while submerged, pump the primer until full.  Works on literally every one so far.  Why is this?  It doen;t mater if you run it out of fuel to store or leave fuel in it. 

[Fordiesel69 226]

I can;t be the only one working on these........  we all own this stuff right?

[rmaynard 14,932]

I use Stihl and Echo products. I never have that problem. Two or three presses of the primer bulb and mine start right up. I do however use ethanol-free gas, but I don't think that has anything to do with it. Never had any problem when I used 10% ethanol gas either.

[Rob R 951]

Logically I think what happens is the diaphrams dry out (especially with the ethanol fuel mix in gas today) and they will not flex, no flex no pumping of fuel what you do solves the problem much as a prime does you are introducing initial fuel to the carb and getting the diaphram moist and pliable i.e. able to suck new fuel.

[Fordiesel69 226]

I would agree on carbs that do not have primer bulbs.  But the primer is soft and flexible.  It almost seems like somthing inside the carb is not sealing the action of the primer and letting the suction from the primer bulb bleed to somewhere.

[Terry M-(Moderator) 2,128]

I use Stihl and Echo products. I never have that problem. Two or three presses of the primer bulb and mine start right up. I do however use ethanol-free gas, but I don't think that has anything to do with it. Never had any problem when I used 10% ethanol gas either.

​Same as above...Have primer bulbs in my Echo grass trimmer , Blower and my Lawn Boy Mower with never a problem ...

[Fordiesel69 226]

Its not a brand thing, as my echo and husqvarna had this issue, as well as tons of people on CL that I was able to buy some stuff and fix it for resale.  It *could* affect any of the small carbs.  I am just starting to notice this issue more.

[Rob R 951]

I would agree on carbs that do not have primer bulbs.  But the primer is soft and flexible.  It almost seems like somthing inside the carb is not sealing the action of the primer and letting the suction from the primer bulb bleed to somewhere.

​Yes the diaphragm is drying out.....

[Terry M-(Moderator) 2,128]

Its not a brand thing, as my echo and husqvarna had this issue, as well as tons of people on CL that I was able to buy some stuff and fix it for resale.  It *could* affect any of the small carbs.  I am just starting to notice this issue more.

​Never said it was a brand thing ...just meant to state what I had..    All of my stuff is older and it works fine.    I agree, anything rubber can dry out and crack/rip with age....   maybe just lucky I guess.

[clem 28]

If these are two cycles, maybe with some fuel evaporation and separation from the two cycle oil that causes the oil that's left behind to gum things up a bit. No proof of that, just a guess.

[buckrancher 2,678]

never had a problem

[wallfish 15,970]

Never had this issue either, unless the bulb was bad. Had plenty of them which got dried up and cracked.

I've had some luck soaking dried diaphragms for a couple of days in a can of carb cleaner. Loosens them up and makes them pliable again. I work on a bunch of that stuff and get sick of ordering diaphragms for every one. The soaking works about 75% of the time plus a good carb clean but it must be intact with no holes or tears. Works best on the ones that are just a little stiff but won't help if they already turned into crackers

[Rob R 951]

Never had this issue either, unless the bulb was bad. Had plenty of them which got dried up and cracked.

I've had some luck soaking dried diaphragms for a couple of days in a can of carb cleaner. Loosens them up and makes them pliable again. I work on a bunch of that stuff and get sick of ordering diaphragms for every one. The soaking works about 75% of the time plus a good carb clean but it must be intact with no holes or tears. Works best on the ones that are just a little stiff but won't help if they already turned into crackers

​

Never had this issue either, unless the bulb was bad. Had plenty of them which got dried up and cracked.

I've had some luck soaking dried diaphragms for a couple of days in a can of carb cleaner. Loosens them up and makes them pliable again. I work on a bunch of that stuff and get sick of ordering diaphragms for every one. The soaking works about 75% of the time plus a good carb clean but it must be intact with no holes or tears. Works best on the ones that are just a little stiff but won't help if they already turned into crackers

​Agree totally I usually soak then in kerosene with a touch of Marvel Mystery oil.......

[Lagersolut 613]

I've never had a problem, had a Homelite trimmer for over 15 years that ran and started flawlessly every year until my cable broke that was a discontinued part that I searched every avenue for NOS with no luck and had to scrap it .  replaced with a Stihl .

[bmsgaffer 2,043]

I had that problem on my dad's old blower, turned out it was the fuel lines becoming dry and getting micro cracks. It wouldn't be enough to leak, but was enough to let air through and not prime. New fuel and vent lines solved it right up! 

My current equipment has not shown any of these symptoms.

[Don1977 604]

I always dump any gas mix back in to the can and let my weed eater run dry before putting it up. Have not had any problem with it. I did have to replace the gas line with the filter and vent as it was pulling air and would not pump gas to the carb.  That was after a lot of years of use.                                                                                   

[alswagg 128]

They are simply getting old and need some service.  Not a big deal to change these out.