Yanmar Cover Gasket 129795-49551 — 4JH Series Marine Diesel Engine
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Yanmar Cover Gasket 129795-49551
This genuine Yanmar OEM cover gasket seals the inspection or timing cover on 4JH series marine diesel engines. Replacing this gasket during any cover removal is essential — reusing a compressed gasket is one of the most common causes of post-service oil leaks. The OEM part ensures exact material composition, thickness, and cut dimensions for a leak-free seal against Yanmar's machined mating surfaces.
Part Details
- Part Number: 129795-49551
- Brand: Yanmar
- Type: Cover Gasket
- System: Engine Sealing / Cover Assembly
- OEM / Aftermarket: Genuine OEM
- Engine Family: Yanmar 4JH Series Marine Diesel
Compatible Applications
- Yanmar 4JH series marine diesel engines
- Verify fitment using your engine model number and serial number against the Yanmar parts diagram for your specific variant (4JH2, 4JH3, 4JH4, 4JHE, 4JH-TE, 4JH-HTE, 4JH-DTE)
- Consult your Yanmar service manual parts diagram to confirm cover position and gasket part number before ordering
Service Interval
- Replace any time the cover is removed — never reuse a previously compressed gasket
- Inspect for oil seepage at every scheduled service interval (250 hours or annually)
- Replace immediately if oil weeping or seepage is observed at the cover joint
Related Parts
- Yanmar OEM Bonnet Gasket Valve Cover 121450-11310 — valve cover gasket for Yanmar diesel engines
- Yanmar OEM Cover Gasket 3JH Series 123325-35140 — cover gasket for 3JH series engines
- Yanmar Gasket Set 728171-92601 — complete gasket set for full engine service
- Yanmar Oil Filter 4JH — OEM Part 129150-35170 — OEM oil filter for 4JH series service
- Yanmar OEM Coolant Filler Cap — 4JH Series 129673-44131 — cooling system service item for 4JH engines
Technical FAQ
Q: Can I reuse this gasket if the cover was only briefly removed?
A: No. Cover gaskets compress and conform to surface irregularities on first installation. Even brief removal breaks that seal. Always install a new gasket.
Q: Do I need sealant with this gasket?
A: Yanmar OEM gaskets are typically installed dry. Do not add RTV or sealant unless specifically called out in your Yanmar service manual for this cover position.
Q: What torque spec should I use?
A: Follow the torque sequence and values in your Yanmar 4JH service manual. Uneven torquing is a leading cause of gasket failure and cover warping.
Q: How do I confirm this is the right gasket for my engine?
A: Cross-reference your engine model and serial number with the Yanmar parts diagram for your specific 4JH variant. The serial number determines which sub-variant and parts revision applies.
Parts Desk Insights
This gasket comes up most often during timing cover or inspection cover service on 4JH engines — typically when a mechanic is in the engine for a belt service, injector work, or investigating an oil seep at the front of the engine. The most common mistake we see is customers trying to reuse the old gasket or using a generic cut gasket that doesn't match the bolt pattern exactly. Always replace with OEM. If you're seeing a slow oil weep at the cover and the fasteners are already at spec, the gasket has likely taken a set and needs replacement — retorquing won't fix it. If you're doing a full service, consider ordering the complete gasket set alongside this part to cover everything in one visit.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 1-3 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.