Multiquip 1685321090 Piston Ring Assembly +0.25MM

The Multiquip 1685321090 Piston Ring Assembly +0.25MM is a genuine OEM component designed for the DAC7000SS, DAC7000SSW, and DAC7000SSA ultra-silent diesel generator series, as well as DLW300ES, DLW300ESA, and DLW300ESA1 diesel light welder units. As a genuine Multiquip OEM part, it is manufactured to the exact oversize specification required for engines that have been bored or honed to the +0.25MM service dimension — ensuring proper sealing and compression recovery during engine rebuild. This piston ring assembly is the correct replacement when restoring engine performance on these DAC and DLW series machines, and verifying the +0.25MM oversize match to your bore is essential before installation.

Key Features

• Oversize-Specific Sealing Integrity — Engineered to the +0.25MM oversize dimension, these rings maintain proper wall contact and combustion sealing against a correctly bored cylinder — standard-size rings will not achieve this.
• Genuine OEM Specification — Sourced directly from Multiquip as an OEM assembly, the ring set matches the original material grade, ring gap tolerances, and profile geometry specified for these diesel engines.
• Direct Engine Rebuild Fit — Designed to drop in as a complete ring assembly during piston and cylinder service, pairing directly with the appropriate oversize piston for these engine configurations.
• Confirmed Fitment — Compatible with DAC7000SS, DAC7000SSW, and DAC7000SSA ultra-silent diesel generators and DLW300ES, DLW300ESA, and DLW300ESA1 diesel light welders.
• Compression and Oil Control Restored — A worn or broken piston ring causes loss of compression, increased oil consumption, and excessive blowby — replacing with the correct oversize assembly restores rated engine output and efficiency.
• Combustion System Safety — Proper piston ring sealing prevents combustion gases from entering the crankcase, reducing the risk of oil degradation and pressure buildup in the engine.

Piston rings form the critical seal between the piston and the cylinder wall inside a diesel engine. They serve three roles: holding combustion pressure above the piston to generate power, preventing oil from entering the combustion chamber, and transferring heat from the piston into the cylinder wall. When rings wear, break, or lose tension, compression drops, fuel efficiency falls, and oil can burn off — symptoms that worsen quickly under load. The +0.25MM designation on the Multiquip 1685321090 indicates this is an oversize ring set, intended for use only when the cylinder bore has been machined to that oversize dimension as part of a proper engine rebuild.

Part Details

Compatibility & Fitment

Verify Before You Order

Fitment is machine-number and revision-specific; always confirm your model and serial number against the fitment list.

Why Buy From DHS Equipment

Every part is verified against the manufacturer's part number before it ships, so what you order is what arrives. We carry parts from leading OEM brands and our own DHS Quality Parts line of professional aftermarket components. Need help finding the right part? Our team is available to confirm compatibility whenever you need it. Orders are processed fast to keep your jobs on track. We don't just sell parts. We keep you jobsite ready.

Questions? Contact our team at [email protected] or 866-611-9369 — DHS Equipment is here to help you maintain peak performance.