Zama, Walbro Carb issues/rebuild

[Aled Hughes]

Recently I've encountered many zama and Walbro carbing issues on saw rebuilds. Sometimes it's purely a case of a new kit and its sorted but when that doesn't work is where i come up against a brick wall. Could it be a welch plug issue or the check valve below the brass piece? What i'd like to know is is there someone or a company that will refurbish these carbs so they're good to go and as good as new again as they tend to be from older or saws that have been laying around for a while that i completely rebuild thanks 

[openspaceman]

6 hours ago, Aled Hughes said:

Recently I've encountered many zama and Walbro carbing issues on saw rebuilds. Sometimes it's purely a case of a new kit and its sorted but when that doesn't work is where i come up against a brick wall. Could it be a welch plug issue or the check valve below the brass piece? What i'd like to know is is there someone or a company that will refurbish these carbs so they're good to go and as good as new again as they tend to be from older or saws that have been laying around for a while that i completely rebuild thanks 

I cannot help with a company that refurbishes carburetors; it would be interesting to see what causes them to fail beyond needle valves, diaphragms and pumps, all of which are replaceable.

 

For my part I have seen worn butterfly spindles/holes, throttle pumps and check valves cause  air leaks that stop the engine running with either weak mixture or failing to draw fuel. 

[spudulike]

I have never found the need to pull welch plugs and my advice is not to as they are damn difficult to seal up correctly and permanently.

I have had just a very few carbs that have gone bad and have not responded to a clean, carb kit, check valve, reseal of welch plugs or new accelerator pump.

The 020t carb was one that would go temperamental with unstable idle and not respond to any normal fixes. 

It depends what the carb is off and what the issue is as to what action I took. Some have non serviceable accelerator pumps...the 357 springs to mind.

[Macpherson]

Just my 2pence worth, but nearly all the carb problems that I see these days are the result of Ethanol in the fuel.

It's just so damaging to so many different substances in so many different ways and has ruined countless engines around the globe, and is only really in the fuel so that our corrupt, stupid leaders can tick some crazy 

' green ' box while they cut down nature in order to plant palm trees to satisfy this madness.

 

To this end I've been using fuel stabiliser in all my small engines for at least 15 years.. with no probs, Fuel will stay fresh for years and it costs next to nothing... My 2 recommendations would be Ethanol shield and Briggs and Stratton ' fuel fit ' 👍

 

And btw if you find yourself forced to by a new carb you might as well buy it from China and wait a bit as it would seem that's where they're made... so under £20 delivered or + £100 at your main dealer.

 

Bear in mind that an ultrasonic cleaner can often dissolve these blockages behind welsh plugs, but only with the right solvent... so to that end I usually place the carb body in a jam jar with far less solvent than filling the whole tub and then place it in the hot water of the US cleaner for a decent time..

..make sure the lid is loose.... which solvent?.. tried many.. feck knows😁