[ellimistd]

Even on a non comp release equipped saw, it still only takes a few extra pulls to 'prime' a carb on a saw that has been sitting for a while or that has been ran dry. On large displacement, high compression non-decomp saws I've loosened the spark plug a bit to lessen compression when spinning the engine over to get the carb primed (if they're a real bear to pull over). Funny thing is that the machines that most often have purge bulb systems are the ones with small displacement engines (often consumer equipment) that aren't hard to pull over anyways.

[limikael]

However, I've now been told that after running under load for awhile, the saw starts shooting fuel out the primer bulb and it loses most if its power. Is that true? Seems goofy to me, so I thought I'd ask the Forum for another opinion. Anybody else encounter this?

[darich]

It has a choke. The official parts diagram says that the part is a Primer housing but it also says in the Note: Purge. The part # is 503 93 66-01. However, the starting instructions want you to press the primer several times when starting a cold engine. here

[hritzen]

I don't like purge bulbs at all. The bulb and lines are another potential source for air leaks (and they can be difficult to service as you've pointed out). If the engine has a comp release, than a purge bulb system is totally unnecessary, as you can easily spin the engine over several times, allowing the pump section of the carb to pull fuel and clear out the air.

[sarah331]

To replace the primer bulb on this saw requires considerable mechanical take down and potentially several hours of work to replace. That's a poor design, so I recommended running the saw as is because it starts about the same as all my Stihl chainsaws that have no primer bulb and it appears to run OK.

[rydiamage]

I recently serviced a Husky K760 chop saw that has a primer bulb with a small crack in it. The saw starts and runs fine without even using the primer bulb (choke three or four pulls until a pop and then one or two pulls with choke off). When warm, the saw starts on one pull with choke off.

[birddump]

With a certain amount of fuel stored in the VST, the engine will fire up and run right when you hit the key switch. Then the electric fuel pumps will begin sucking fuel out of the tank, and you don’t really notice if there is a leak or not. That is unless it is a pretty bad leak!

[Stobrawa]

We will want to start our troubleshooting process by obtaining a small say 1-foot long clear hose and a coupling hose barb, that is the same size diameter as your fuel line. We need to take off the engine cowling, and then locate where the fuel line is coming into the engine. Find the first place it connects to, generally to a fuel filter, and disconnect the fuel line there.

[SomeoneD]

Insert the clear hose into the fuel line, prime up the engine, and start it up! Let it run for a little while and carefully watch the fuel passing through the clear hose.

[Hariposter]

Assuming I needed a new primer bulb, I took the cover off the carb and pulled the primer bulb out. But it appears that the hole in the bulb is by design, which I later read could be the case for a primer bulb. So my questions are, is there really supposed to be a hole in the bulb for this engine, and if the hole is supposed to be there, why does gas leak out of it? Is there a bad seal somewhere else that is providing a vent to allow it to leak from the primer bulb hole? Any ideas for what may be the problem?

[knyaz]

Remove the carb, and then remove the float bowl. Check the float bowl jet (which is the bowl screw) and make sure the jets both horizontal and vertical are clean and open. Tip the carb upside down and remove the float pin and float with needle attached. Look in the float needle passage and you should see the red float seat at the bottom of the passage. This is where a #5 crotchet hook would come in handy as you need to remove this seat. If you have no hook, but compressed air, you can blow through the fuel inlet and try to pop the seat out. Put your thumb over the passage to prevent the seat from flying who knows where. No air or hook try bending a stiff paper clip to dig the seat out.

[wizeman]

With the seat out clean the passage way with carb cleaner. Now you must find a drill bit slightly smaller than the passage way, to be used to press in the new seat. Apply a very, very small amount of a very light lube to the new seat. 3-1 oil or lighter, to help seat it better. Carefully insert the new seat in the passage way with the rings on the seat down toward the carb body. Slowly and carefully force the seat down with the back end of the drill bit. Once it is seated, check to see that it did not flip and the rings are up. If everything looks correct, attach the new needle to the float and install with the float pin centered. It everything is correct, the float should seat level to the carb body, when looking at it upside down. If everything looks good reattach the float bowl, making sure that both the bowl gasket and the nut gasket seal properly. Reinstall on the engine and test unit. Remember to have patience and take your time. Good luck, but I don't think you'll need it.

[MiniMan36x]

Likewise, is primer bulb necessary? A primer bulb is important because it is helps to fill the carburetor with the correct amount of fuel. It does this by pulling fuel through the fuel line. You may need to fix or replace your primer bulb if: It is not creating proper suction. here

[marieellis444]

In this manner, why does my primer bulb not work?

[aq8586]

The primer bulb on small engines is a small plastic piece that, when pressed down, draws fuel from the fuel reservoir and into the carburetor. The carburetor is a part of the engine that mixes fuel and air together to make a combustion. Most weed trimmers have a primer bulb to prime the carburetor. here

[Pegasus-Rider]

When the primer bulb isn't working, it may be a problem with the bulb itself, with the fuel lines that feed fuel to the bulb or both. The same goes for fuel lines. When they've hardened and cracked, they let in air, which makes it impossible to draw the fuel into the carburetor properly.

[Gavin Andresen]

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