149-2457 149-2311 140-3280 Fuel Filter Pump Air Filter – Direct Fit for Onan KY 4000

Verified Variant Fitment — Serial-range mapping across KY 3600/4000 Series confirms port orientation, seal profile, and superseded number equivalence before any shipment leaves Guangzhou.

Technical Specifications

Application Suitability

Why the Same Part Number Ships in Multiple Configurations

Cross-reference tables copied between sellers carry errors forward, turning a routine filter and pump swap into a trial-fit gamble on site.

A single base reference like 149-2311 can map to several physical variants across the KY 3600 and KY 4000 Series production run. Fuel pump port orientation shifts between early and late serial ranges. The air filter flange profile changed when Onan updated the housing design on later Camp Power/QG RV units. Buyers relying on a worn nameplate or a single superseded number often receive a component that physically fits the mounting points but misaligns on the fuel line connection. [NEED_CITE: aftermarket cross-reference verification standards for generator fuel systems]

The Fuel Filter Fuel Pump Air Filter for Onan KY 4000 cross reference fitment challenge compounds when fleets mix MicroLite and MicroQuiet units under one maintenance program. Each variant carries subtle interface differences that generic interchange tables do not capture.

Serial-Range Mapping Across the KY Family

Identification starts with the machine model and serial prefix, not the faded label on the old component. The KY 3600 Series spans several production years, and the fuel pump interface changed mid-run. When a buyer provides only "KY 4000" without the serial range, the correct 149-2457 fuel filter variant and the matching 149-2311 or E11006 fuel pump variant cannot be confirmed with certainty. Cross-reference verification covering superseded and alternate numbers — including E11007 and 1403280 — ensures the dispatched set matches the physical machine standing in the workshop.

Interface Verification Before the Box Opens

The critical check on this Fuel Filter Fuel Pump Air Filter for Onan KY 4000 cross reference fitment involves three physical interfaces. The fuel pump port position must align with the existing fuel line routing — a deviation of even a few degrees forces hose re-bending in a tight RV generator compartment. The fuel filter seal must seat against the housing without gap or over-compression. The air filter flange shape — rectangular versus rounded — must match the housing molded into the specific KY variant. [NEED_CITE: dimensional tolerance requirements for small-engine fuel system interfaces]

Dimensional tolerance held to ±0.15 mm means each component bolts on without modification when the correct variant is identified.

Specification Breakdown for Field Reliability

The multi-layer cellulose-synthetic blend in the fuel filter delivers 10-micron absolute filtration per SAE J1852, capturing particulate that would otherwise score the precision-machined brass internals of the pump. The 4–6 PSI pressure output suits the low-pressure carburetor feed circuit on KY 3600 and 4000 Series generators — higher pressure would overwhelm the float needle. Operating temperature range of -20°C to +60°C covers desert RV parks and cold-start conditions at altitude. The oiled cotton gauze air filter media provides high-flow filtration in dusty environments like remote construction sites, while the reinforced molded rubber sealing flange prevents unfiltered air bypass under vibration.

The Hidden Cost of Skipping Variant Confirmation

A fuel pump that physically mounts but has the wrong port orientation forces a field workaround — improvised hose routing that kinks under thermal expansion and starves the carburetor during sustained load. An air filter flange that almost fits allows dust ingress past the seal edge, accelerating cylinder wear in ways that do not surface until the next scheduled inspection. These are not warranty claims; they are silent failures attributed to other causes. [NEED_CITE: generator fuel system contamination failure modes in mobile RV applications]

Forced-fitment damage and early component degradation cost more in machine downtime than a pre-shipment variant check.

Why Procurement Starts with Fitment Verification

Own production on selected filter lines plus qualified sourced supply for pump and air components means every item in this set ships under one account and one warranty term. Eight product categories allow a complete generator service job — filters, seals, gaskets, fasteners — to consolidate into one dispatch. Minimum order from one set supports emergency single-unit repairs without blocking on volume thresholds. Part identification from machine model, photograph, or nameplate image resolves situations where the original reference is unreadable. Cross-reference verification covers superseded numbers and alternate references across the full KY family. Sample supply available for physical fitment confirmation before any bulk commitment proceeds.

Documentation & Verification

• Commercial invoice listing each variant reference (149-2457, 149-2311, 140-3280) with serial-range match noted
• Part compatibility sheet mapping superseded and alternate numbers, marked reference only
• Dimensional inspection record covering port orientation, filter seal profile, and air filter flange shape
• Warranty terms covering manufacturing defects for 3–12 months from dispatch
• Packing photographs showing each component individually protected before crating
• HS code and customs documentation support for international generator parts shipments

Fitment Check Before Installation

• Compare fuel pump port orientation against the removed unit before connecting fuel lines
• Verify fuel filter seal diameter and profile match the housing bore on your specific KY variant
• Confirm air filter flange shape — rectangular or rounded — against the housing opening
• Check fuel pump voltage at the connector to confirm 12V DC supply before final mounting
• Seat the air filter and run the generator under no-load to verify seal integrity before enclosure closure
• If any interface does not align, halt installation and contact technical support with photographs

Request a Fitment Verification

Provide the generator model designation and serial number prefix from the nameplate, or send a clear photograph of the existing fuel pump and air filter in place on the unit. This allows confirmation of the correct variant across the KY 3600, KY 4000, KYD, and MicroLite ranges before any commitment to quantity.

Frequently Asked Questions

Q: How do I confirm these part numbers fit my specific Onan KY unit? A: Share the generator model and serial prefix from the nameplate. Cross-reference verification maps 149-2457, 149-2311, and 140-3280 against your exact production variant, confirming port orientation, seal profile, and flange shape before dispatch. Photographs of the installed components help when the nameplate is unreadable.

Q: My old part number looks different — is it still the correct replacement? A: Superseded and alternate references such as E11006, E11007, and 1403280 map to the same physical components across different production periods. Provide your old number and the machine model so the cross-reference sheet can confirm equivalence and flag any variant differences that affect fitment.

Q: Why does the same base number have multiple alternate references? A: Production changes across the KY 3600 and 4000 Series lifespan introduced updated part numbers for components that fit the same machine family. Alternate references reflect these revisions. Verification against your serial range ensures the dispatched variant matches the interfaces on your specific unit.

Q: I only have the machine model, no readable part number — can you still match it? A: Yes. Identification from machine model alone is possible for KY 3600, KY 4000, KYD, Camp Power/QG RV, and MicroLite variants. Providing the serial prefix narrows the match further. A photograph of the existing fuel pump and filter housing helps confirm variant-specific details.

Q: Can I get a sample set to test fitment before ordering in bulk? A: Sample sets are available for physical fitment testing. This allows verification of port alignment, seal seating, and air filter flange match on your actual generator before committing to a larger order. Confirm machine model and serial range to receive the correct variant sample.