Products Description
EH12 Generator Piston Assembly Kit | Complete Piston, Ring Set, Wrist Pin & Circlips for Robin-Subaru EH12 4-Stroke Engines
OEM-Spec Aluminum Alloy Piston with Valve-Relief Crown, Molybdenum-Coated Compression Rings, Slotted Oil Control Ring & Hardened Steel Wrist Pin
EH12 Generator Piston assy
The piston is gravity-cast from a high-silicon aluminum alloy and CNC-machined at the ring grooves, wrist pin bore, and crown. The crown features two semi-circular valve relief pockets - these provide clearance for the intake and exhaust valves when the piston reaches top dead center, preventing valve-to-piston contact that would bend valves and destroy the piston. The ring set includes compression rings for combustion sealing and an oil control ring with a slotted, wavy internal structure for cylinder wall oil scraping. A hardened steel wrist pin and two wire circlips (in a sealed red packet) complete the assembly. Typical rebuild triggers include: low compression from worn rings (hard starting, power loss), blue exhaust smoke from oil passing the rings, piston skirt scoring from low-oil operation or dust ingestion, and routine engine overhaul during major service.
Technical Profiles & Materials
Hardened Steel Wrist Pin：
The dark grey wrist pin is a hollow cylindrical shaft machined from case-hardened carbon steel, polished to a low-friction surface finish. It operates in a full-floating configuration: free to rotate in both the piston pin bore and the connecting rod small-end bushing. This full-floating design distributes wear evenly around the pin circumference rather than concentrating it on the loaded side, extending pin and bushing life.
Complete Kit in Model-Specific Packaging ：
The kit arrives in a brown cardboard box clearly labeled "EH12" for unambiguous model identification - no mix-ups with similar-appearing EY or EX series piston kits. Inside, the piston, ring set (in a sealed clear bag), wrist pin (in a protective plastic sleeve), and circlips (in a red packet) are individually packaged to prevent transport damage and component mixing. This organized packaging allows the rebuilder to verify all components are present before beginning disassembly, preventing the mid-rebuild discovery that a circlip or wrist pin is missing.
Technical Specifications
| ITEM | DETAILS |
| Type | Complete Piston Assembly Kit - Piston + Rings + Wrist Pin + Circlips |
| Application | Robin-Subaru EH12 (121 cc, 3.5 HP) 4-stroke OHV engines on generators, water pumps & compact equipment |
| Code | 1701048 |
| Material | High-silicon aluminum alloy piston, molybdenum/chrome cast iron compression rings, slotted steel oil control ring, hardened steel wrist pin, spring steel circlips |
| Details explanation | Standard-size piston & ring kit. Piston crown with dual valve reliefs. Slotted oil control ring design. Full-floating wrist pin. Complete kit: piston + ring set + wrist pin + 2 × circlips (red packet). |
| Brand Name | SeaSummer |
| Operating Temp | −20 ~ +300 °C (piston crown) |
| Delivery Time | 30 Days |
| Packaging | Cardboard packaging |
Products Application
Small-Engine Rebuild Services & Fleet Maintenance
For independent small-engine repair shops and equipment rental fleets maintaining multiple EH12-powered machines, stocking the standard-size piston kit ensures rapid turnaround on the most common major engine repair. The individually sealed component packaging protects the rings from corrosion and the wrist pin from surface damage during shelf storage - maintaining rebuild quality even for kits that have been in inventory for months. The labeled box allows quick visual identification of the correct kit from a shelf of engine parts, reducing the time a mechanic spends locating components.
Low-Oil Damage & Dust Ingestion Rebuilds
The EH12's compact sump capacity (typically 0.6 liters) makes it vulnerable to low-oil damage if the oil level is not checked regularly - common on generators stored for months and deployed without a pre-start oil check. Low oil causes piston skirt-to-cylinder wall scuffing that scores both surfaces. Dust ingestion through a degraded or missing air filter - common on construction-site water pumps - embeds abrasive silica in the ring grooves and accelerates ring and piston wear. In both failure modes, the piston, rings, and wrist pin must be replaced together as the wear is distributed across all components.
EH12-Powered Portable Generators & Water Pumps
The primary application. The EH12 engine drives compact 1–2 kVA portable generators and 1–2 inch centrifugal water pumps. These machines are used for residential backup power, camping, small-scale irrigation, and construction site dewatering. The engine's small displacement means it operates at relatively high RPM (3,000–3,600 governed) to produce rated power, placing significant wear on the piston rings over hundreds of operating hours. A generator that becomes hard to start, produces blue smoke, or trips its overload breaker at loads well below its rating is exhibiting classic ring-wear symptoms that this piston kit resolves.
Quality and Craftsmanship Details
Products Package
About Us
As a premier garden machinery parts supplier, Jiaxing Norsun Trading Co., Ltd. bridges global distributors with over 100 vetted China manufacturers. We streamline your B2B supply chain through strict quality control, flexible production, and factory-direct wholesale pricing. Partner with us for reliable, high-volume sourcing of precision-engineered outdoor power equipment components.
Trusted Partnership Power
YOUR PROFESSIONAL ONE-STOP SOURCE
FOR 10000+ OUALITY PARTS
Verified Factory Excellence
BACKED BY 200+ TRUSTED FACTORY PARTNERS
Production process
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Customer Reviews
FAQ
Q: Are you an impartial industrial components dealer or a direct China water pump factors factory?
A:We are a direct, ISO9001-certified engineering water pump components manufacturing facility and precision fluid-control factor manufacture exporter primarily based in China. We function our personal cleanroom injection molding bays, computerized ultrasonic welding arrays, computerized hydraulic stress check stations, and clean-room packaging lines, passing direct-factory wholesale price financial savings straight to your element procurement margins.
Q: Can your manufacturing unit furnish full certification forms for food-contact or consuming water compliance?
A: Yes, absolutely. For food, beverage, or scientific applications, our manufacturing unit makes use of one hundred percent virgin, un-recycled polypropylene resins accompanied by means of fabric traceability certificates. We mechanically furnish B2B purchasers with complete FDA compliance documentation, NSF-grade compound declarations, and RoHS/REACH chemical protection screening sheets to make certain clean clearance thru worldwide customs.
Q: Do you provide customization picks for distinctly corrosive fluids like sturdy acids or ozone?
A: Yes, we are a thoroughly succesful OEM/ODM supplier. For aggressive chemical or ozone environments, we can improve the 12x26.5mm valve configuration in our factory: substituting the general PP housing with top class PVDF (Fluoropolymer) and changing any steel springs with Hastelloy or whole springless gravity-ball architecture, making sure final chemical resistance.
Q: How do we impervious a pattern batch to execute computerized lifecycle and burst-pressure testing?
A: We relatively inspire complete laboratory contrast earlier than logging mass grant agreements. We can ship a pattern lot of 5-10 gadgets of our inventory 12x26.5mm take a look at valves for assessment (setup costs and DHL/FedEx air freight apply). Once the factors pass by your inner lifecycle verification and a formal wholesale quantity manufacturing contract or container run is locked in, the sampling charges are a hundred percent credited returned to your industrial balance.
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