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.