Kubota V3800 Injection Pump 1J500-50505 | Genuine Kubota Reman Supply Pump

The Kubota 1J500-50505 is a genuine Kubota remanufactured high-pressure fuel injection pump, the supply pump assembly for the Kubota V3800 common rail diesel engine. It is the current number in Kubota’s 1J500-505xx supply pump series and the factory replacement for every earlier number in that chain. The supply pump builds the rail pressure the entire common rail system depends on. When it wears out you get hard starting, low power, rail pressure fault codes, and in the worst cases metal debris that takes out the injectors and rail with it. A genuine Kubota reman pump, built on the original Denso platform, is the way to fix it once and fix it right.

Application & Fitment

Confirmed applications for the 1J500-50505 supply pump:

• Engines: Kubota V3800-CR-T, V3800-CR-TE4, and V3800-CR-TIE4 (3.8L turbocharged common rail)
• Kubota M8560 utility tractor
• Kubota SVL90-2 compact track loader

The Kubota M9960 tractor uses the same V3800-CR-TE4 engine as the M8560, and aftermarket listings also place this pump family on the M4N narrow tractor, so those machines very likely take this pump as well. Kubota has superseded this pump several times, so check the number stamped on your existing pump before ordering, or simply call us with your engine model and serial number and we will verify the exact part for your machine.

Cross-Reference Part Numbers

The 1J500-50505 replaces or cross-references the following numbers:

• Kubota 1J500-50500, 1J500-50501, 1J500-50502, 1J500-50503, 1J500-50504 (earlier numbers in the supersession chain)
• Kubota reman program KEARP-1J500 (K1J500-50500 / K1J500-50501)
• Denso 294000-1720 and 294000-1721 (the OE Denso supply pump numbers for this application)

Frequently Asked Questions

Is this a new or remanufactured pump?

This is a genuine Kubota remanufactured supply pump from Kubota’s factory reman program. Reman pumps in this program are rebuilt with OEM Denso components, including a new suction control valve (SCV), and built to perform to factory spec. Reman is the standard way Kubota supplies this pump, and buying it through an authorized Kubota dealer means real warranty support, not a gray-market gamble.

How do I know the supply pump is my problem?

Typical failure symptoms on the V3800 common rail are hard starting or no start, low rail pressure fault codes, power loss under load, and engine derate. A failing pump can also shed metal into the fuel system, and if that has happened the injectors, rail, and lines need to be inspected and cleaned or replaced too, or the new pump will be contaminated on day one. We diagnose and repair common rail systems in-house every day, so if you are not sure the pump is the culprit, call us before you spend the money.

Will this pump fit my machine?

If the pump on your engine is stamped 1J500-50500 through 1J500-50505, this is the correct current replacement. Kubota advises verifying the number on the physical pump rather than relying on the machine model alone. Call us at 530-668-0818 with your engine model and serial number and we will confirm fitment before you order.

Why buy your Kubota supply pump from Valley Fuel Injection

Valley Fuel Injection & Turbo is an authorized Kubota dealer and a dedicated diesel fuel injection shop in Woodland, California, serving Northern California and Nevada since 1993. We do not just sell this pump in a box. We test, diagnose, and rebuild the very common rail systems it serves, so you get straight answers on diagnosis, fitment, and what else to replace when a pump fails.

Pricing & availability: this genuine Kubota reman supply pump is supplied to order. Call 530-668-0818 or request a quote for current pricing, availability, and lead time. Have your engine model and serial number ready so we can confirm the exact pump for your machine.

Why do I see this pump cheaper online?
Short answer: it is usually not the same part — and a pump failure does not stay in the pump. Read why ↓

Search any OE number and eBay, Amazon and a dozen storefronts will show it well under dealer cost, sold by outfits with no name, no address and no phone number. We lose business to those listings every week — and we see a lot of them come back through our shop. Here is what is actually different.

• The part number proves nothing on its own. Counterfeit injectors and pumps are stamped with the same OE numbers as the real thing, in housings cast to look identical. The number in the listing title tells you what the seller claims it is, not what came off an OE line.
• “Remanufactured” is not a regulated word. A genuine reman unit is stripped to bare components, has its wear parts replaced — nozzle, plunger and barrel, solenoid, seals — and is then run on a calibration bench until it meets the original flow and response spec. A cheap one is very often cleaned, resealed, painted and shipped. Both get called remanufactured.
• No full teardown, so no idea what is worn. A proper rebuild means the unit comes apart completely and every part gets inspected and measured against spec — not just the ones that are obviously bad. Skip the teardown and you are reusing worn internals inside a freshly painted housing. It will run on the truck. It will not last.
• No factory-spec bench load testing. A unit is not finished until it has been run under load on a test bench and made its numbers across the range, not just at one easy point. That bench time is most of what you are paying for. Sellers working on price cut it first, because nobody can see it in a photo.
• The warranty has to be honored by someone. Everything we remanufacture in house carries a one-year warranty, with 30 days on electrical components. Parts we supply as an authorized dealer carry the manufacturer’s own warranty. Either way you call us, a real shop in California, and we sort it out. A marketplace warranty usually means shipping the part overseas at your own cost and hoping for a reply.
• No core program. We credit your rebuildable core back in full. Discount sellers generally will not take one, so the gap narrows the moment you account for the core you are now stuck holding.
• A pump failure does not stay in the pump. When a high-pressure pump comes apart it sends metal downstream through the rails, the lines and every injector. That is the whole reason fuel contamination kits exist. A pump that was never tested to spec is the cheapest possible way to buy that repair.

We are an authorized dealer and a working fuel-injection shop — we have been rebuilding and testing this hardware in Woodland since 1993, and the people who answer the phone are the people who run the benches. Not sure this is the right part for your engine? Call us with your serial number before you order and we will confirm it. Send your rebuildable core back and the core charge is refunded. And if a price somewhere else looks too good, call 530-668-0818 and we will tell you straight whether it is a deal or a problem.