Products Description
GX390 +0.50mm Oversize Piston Assembly Kit | Second-Stage Generator Engine Cylinder Rebuild
Second-Rebore Precision-Matched Reciprocating Core featuring Hypereutectic Alloy Piston and Pre-Set Ring Pack for 389cc 4-Stroke Powerhead Cylinder Lifecycle Extension.
Generator GX390 Piston assy +0.5
The GX390 +0.50mm second-stage oversize piston assembly constitutes the advanced cylinder-restoration solution engineered for engines that have already exhausted their first +0.25mm oversize service life or sustained bore damage exceeding the +0.25mm cleanup threshold. This kit enables a second precision overbore to 88.50mm-removing the accumulated taper, out-of-round, glazing, and scoring from the cylinder walls to provide a fresh, factory-spec sealing surface. The matched piston and pre-gapped ring set restores the exact piston-to-cylinder clearance, compression integrity, and oil-control discipline required to return a high-hour GX390 generator or industrial pump engine to full-rated power output. Purpose-calibrated as the definitive second-life solution for engines that would otherwise be condemned to the scrap bin.
Technical Profiles & Materials
88.50mm (+0.50mm) Hypereutectic Alloy Core High-silicon hypereutectic aluminum piston machined to 88.50mm oversize diameter. Matches OEM piston-wall clearance for rebored cylinders, eliminating piston slap, excessive oil burn and compression leakage from worn standard bore setups.
Overbore-Stage Calibrated Ring Set Complete +0.50mm matching ring kit: chrome barrel top ring, taper second ring, 3-piece oil control ring. Factory pre-gapped for 88.50mm bore, no manual filing required to prevent ring butt seizure and cylinder scuffing during break-in.
Thermal Cam-Ground Skirt Geometry Optimized asymmetric oval skirt offsets uneven thermal expansion between piston crown and pin bosses. Forms uniform cylindrical contact under sustained high loads from generators and industrial water pumps.
Hardened Floating Wrist Pin with Dual-Circlip Locking Case-hardened floating steel wrist pin secured by heavy-duty circlips. Stays firmly locked under strong reciprocating inertia and peak combustion pressure, avoiding catastrophic cylinder wall damage caused by loose circlips on rebuilt oversize engines.
Technical Specifications
| ITEM | DETAILS |
| Type | Second-Stage Oversize Piston Assembly (+0.50mm) |
| Application | GX390 Generator / Water Pump / 389cc 4-Stroke (Post-Wear Engine Rebuild) |
| Code | 1604109 |
| Material | Hypereutectic Al-Si Alloy / Hard Chrome Ring / Hardened Steel Pin / SS Circlips |
| Details explanation | 88.50mm (+0.50mm Oversize, Second Overbore Stage) |
| Brand Name | SeaSummer |
| Operating Temp | -20°C to +300°C (Piston Crown) |
| Delivery Time | 30 Days |
| Packaging | Cardboard packaging |
Products Application
Cylinder-Block Lifecycle Management for Fleet Operations
An essential advanced rebuild consumable for generator service centers, industrial equipment distributors, and agricultural cooperatives managing high-hour GX390 fleets where systematic cylinder-block lifecycle tracking determines when engines migrate from standard → +0.25mm → +0.50mm rebuild stages.
Catastrophic Bore Damage Recovery After Debris Ingestion
Ideally suited for post-ingestion engine salvage where a broken air-filter element, disintegrated piston-ring fragment, or foreign object drawn through the intake has gouged the cylinder wall beyond the reach of the +0.25mm cleanup bore. The +0.50mm depth removes these deeper defects while still preserving adequate cylinder-wall thickness for continued reliable operation-often the last salvage stage before cylinder resleeving or block replacement becomes necessary.
Worn-Out First-Oversize Engine Lifecycle Extension
Serves as the definitive second-life recovery module for GX390 engines that have already accumulated sufficient hours on a +0.25mm oversize rebuild to require a second overbore, or for engines whose cylinder-wall scoring, seizure damage, or deep wear grooves exceeded the +0.25mm cleanup limit at the time of first inspection. The +0.50mm stage provides the only viable path back to service for these engines without replacing the entire cylinder block.
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
Quality control
Expo experience
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.
Hot Tags: generator gx390 piston assy +0.5, China generator gx390 piston assy +0.5 suppliers
