OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Trimmers and Brushcutters Ryobi Trimmers & Brushcutters Servicing carburettors

I've watched the USA video on cleaning carburettors - then I found this comment online about servicing Walbro carbuettors:

"Don't soak the carb in any harsh chemicals, and don't spray any strong cleaners, like carb cleaner through the main nozzle, or you risk damaging the check valve. I use brake cleaner spray for flushing out the passageways, as it is not as harsh. If the carb has with fuel in it, the varnish and gum deposits may have already damaged the high speed check valve, and plugged some of the fuel circuits beyond hope. But try it, all you will be out is a little time. Be sure to pressure test it to be sure the fuel pump side and inlet needle are holding, do not go over 10 PSI for this test."

Now, I've purchased some carb cleaner, thinking how else could I clean one except to blast something like that through it. But after reading the above, I'm now back to square one - ie. afraid I'm going to damage something. The USA video talks about replacing gaskets & diaphrams. But he doesn't talk about how to cleaning the inside of a carb and how to do so without damaging things like this check valve.

How do I clean the inside of the carb?
Where is the main nozzle he's talking about?
How do I tell a high speed check valve is ok?
How do you do a pressure test?

Is there a book, etc. that goes through servicing a carby step by step, rather than hit and miss by replacing just the gaskets and diaphrams!?

We have the information in the parts list and manuals area of the forum under brushcutters parts list and manuals. It covers Zama, Walbro and Tillitson carby workshop manuals.