# Repair of 1997 Ryobi 775R / Walbro WT-454 carb



## akser (Jun 15, 2008)

I'm posting this partly to help others searching for similar info and partly to get any additional comments or advice before I rebuild it. I'm fairly mechanically proficient but this will be my first carb rebuild. I did just successfully clean and part rebuild a 5 year Tecumseh lawn mower/carb I received for as a swap so this trimmer should be within my abilities.

I have a 1997 Ryobi 775r trimmer, serial number 611000001 and greater. It has a Walbro WT-454 carb (identified from faint stamping on side of carb) which is Ryobi replacement p/n 181621. It ran great until mid-last year (10 years!!), then started to loose power and now this year is hard starting. There is a minor amount of fuel leak from the carb and there are air bubbles in visible in the primer fuel lines and the primer bulb does not completely fill with fuel. The cylinder wall (looking in the exhaust manifold port) looks in OK condition and is shiny metal. There might be some very minor vertical scratches, but the manufacturing cross-hatch is still mainly visible. The fuel lines and primer bulb look in good condition with no leaks or cracking.

From the symptoms I need to rebuild the carb since it has probably fuel hardened. The Ryobi OEM carburetor rebuild kit is 180602. However the Walbro rebuild kit K10-WAT contains all the necessary carb rebuild parts, just add Ryobi carburetor gasket 610675. I think I should also replace the fuel lines, primer bulb and fuel filter while it is apart to head off future problems. I think there are less expensive ways than buying the Ryobi replacement parts but I don't have all those part numbers yet. Standard fuel line will work if I can get a primer bulb and fuel filter.

Should I replace / repair anything else while I'm doing this? While I will get satisfaction from making this work (I am an engineer at heart!) this it is an 11 year old trimmer, and a new one can be bought for about $100.


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## hankster (Jan 1, 1998)

The fuel filter will include the fuel line to the primer. This is a part unique to Ryobi style trimmers as the stem of the fuel filter has to pull through the tank. The primer is the same style as used by others such as some Poulan units. The other fuel lines are pretty standard parts.


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