Genuine Cummins Onan straight exhaust downtube with flange for the HGJBB RV QG 2500 LP and QG 2800 generator series. Connects the generator muffler to the external exhaust pipe. 1-1/8" O.D. 90-day limited warranty.
The Cummins Onan A041L816 is a genuine OEM straight exhaust downtube with mounting flange for the HGJBB generator series — covering the RV QG 2500 LP (propane) and RV QG 2800 (gasoline) models. It connects the generator's internal muffler outlet to the external exhaust tailpipe system, providing the initial downward routing of exhaust gases out of the generator enclosure.
The downtube features an integrated mounting flange for secure attachment to the generator's exhaust outlet and a 1-1/8" outer diameter pipe that connects to standard HGJBB exhaust tailpipe fittings. Using a genuine OEM downtube ensures correct fit at the muffler flange connection and proper exhaust flow geometry for the QG 2500/2800 installation.
Built-in flange provides a secure, bolt-on connection to the HGJBB generator muffler outlet — the correct OEM attachment method for the QG 2500 and QG 2800
Standard 1-1/8" outer diameter tube connects to QG 2500/2800 exhaust tailpipe fittings — the correct pipe size for HGJBB generator exhaust systems
Cummins Onan factory part — ensures correct fit at the muffler flange and proper exhaust flow for the QG 2500 LP and QG 2800 generator enclosures
Fits both the QG 2500 LP (propane) and QG 2800 gasoline HGJBB models — the same downtube is used across both fuel variants of this generator family
This downtube fits the HGJBB series only — the RV QG 2500 LP and RV QG 2800. It is not compatible with larger generator families such as the HGJAB (QG 5500/7000 Marquis Gold) or the KY/MicroQuiet series, which use different exhaust pipe diameters and flange configurations. If your installation requires a longer downtube, Cummins Onan also offers the 155-2425 stainless steel extended downtube (7-1/2") for the QG 2500/2800 series. Confirm your generator's model number from the identification nameplate before ordering.
• One (1) A041L816 Exhaust Downtube with Flange Tailpipe clamps and additional exhaust hardware are not included. Refer to the Cummins Onan HGJBB installation manual for complete exhaust system assembly guidance.
Backed by a 90-day limited manufacturer's warranty against defects in materials and workmanship. Retain your purchase receipt and note the installation date for any warranty service requests.