Carburetor for Homelite CSP4518 / Ryobi RY10518–RY10521 – 308070001 / 309360002

Description

This Homelite CSP4518 carburetor is an aftermarket replacement for the verified Homelite and Ryobi petrol chainsaws listed below. It covers the Homelite 45 cc CSP4518 application and the related Ryobi 46 cc chainsaw families.

The Homelite CSP4518 factory parts list identifies its carburetor assembly as 308070001. Ryobi parts lists for the RY10519 and RY10521 families identify the later carburetor assembly as 309360002.

Homelite CSP4518 Carburetor Fitment

Fits the following chainsaws:

• Homelite CSP4518
  • 45 cc engine
  • 18-inch guide-bar model
  • Type UT74125A
  • Type UT74125D
• Ryobi RY10518
  • 46 cc engine
  • 18-inch guide-bar model
• Ryobi RY10519
  • 46 cc engine
  • 18-inch guide-bar model
• Ryobi RY10520
  • 46 cc engine
  • 20-inch guide-bar model
• Ryobi RY10521
  • 46 cc engine
  • 20-inch guide-bar model

Also fits these documented Ryobi revisions:

• Ryobi RY10519A
• Ryobi RY10521A
• Ryobi RY10519B
• Ryobi RY10521B

The A and B suffixes identify later revisions of the RY10519 and RY10521 chainsaws. Their factory repair-parts lists specify carburetor assembly 309360002.

Carburetor References

Relevant factory references are:

• Homelite CSP4518 carburetor assembly: 308070001
• Ryobi RY10519 / RY10521 carburetor assembly: 309360002

These numbers come from different generations of the shared chainsaw platform. Therefore, the model name remains essential when identifying the replacement.

This product is the complete aftermarket carburetor shown in the listing photographs. Intake gaskets, fuel hoses, filters and external linkages are separate parts unless they are visibly supplied with the product.

Checks Before Installation

Before removing the original carburetor, photograph or mark:

• Fuel-supply hose position
• Purge-return hose position
• Throttle-linkage position
• Choke-linkage position
• Intake-gasket orientation

Compare the mounting holes, intake opening, fuel fittings and linkage arms with the replacement carburetor.

Inspect the intake boot, carburetor adapter, adapter seal and carburetor gasket during disassembly. The CSP4518 parts list identifies these as separate sealing components, while the Ryobi repair sheet also lists the adapter, seal and gasket independently.

After installation, operate the throttle by hand before fitting the outer covers. The throttle must open fully and return to idle without binding.

Finally, check every fuel connection for leakage. Adjust idle speed and mixture according to the service information for the exact Homelite or Ryobi model.

Browse additional chainsaw parts for compatible fuel-system, starter and engine components.