My Account
Shopping Cart

Shopping Cart

0 items in your Cart
View Cart
Subtotal
Track
My Order

Sierra 18-99135 Exhaust Inner Cover Gasket for Yamaha Outboard Motors

Manufacturer

Picture for manufacturer Sierra

Part Number

18-99135
13 reviews
Sale Price

$16.39

3 left at this price

delivery box

Usually delivered within 2 days

Check out with

ApplePay
Authorize Seller Badge
No Hassle Returns

No Hassle Returns

Live-in-stock inventory

Live-in-stock inventory

Fitment guaranteed

Fitment guaranteed

Product Details

The Sierra 18-99135 is a replacement exhaust inner cover gasket engineered for Yamaha outboard motors. Designed as a direct replacement for OEM part number 6H4-41112-A0, this gasket delivers a precise, leak-free seal at the exhaust inner cover — a critical sealing point that protects the engine from exhaust gas intrusion and corrosion-causing moisture.

Sierra gaskets are manufactured to meet or exceed original equipment specifications, making the 18-99135 a trusted choice for both professional marine mechanics and do-it-yourself boaters performing exhaust system service or rebuilds.

Key Features:

  • Direct replacement for Yamaha OEM part number 6H4-41112-A0
  • Meets or exceeds original equipment manufacturer specifications
  • Provides a reliable seal at the exhaust inner cover junction
  • Engineered for the demanding marine environment
  • Sold as a single gasket

OEM Cross-Reference: Yamaha 6H4-41112-A0

It is recommended to replace the exhaust inner cover gasket any time the exhaust cover is removed for inspection or service to ensure a proper seal and prevent exhaust leaks.

smooth and easy

great selection & prices

Did not even know I forgot something! Thanks Autoplicity!!

Very easy & fast to use, and GREAT products.

.............

easy to use site.

good! but if can shipping quickly will be better.

Lowest price I could find. Cheap shipping for the size. Pretty happy

Grate

Good price on my THU-A90275. Had to contact customer service...they were professional and eventually resolved my concern. Called over the phone and the guy told me he couldn't help me with a coupon/refund, but that I had to contact support via email (I guess the phone support and email support aren't one and the same). It took a couple emails, but eventually they refunded me what was due.

Best prices I've found. Trust me I've looked!

Finding what I wanted and price was all good...but after purchasing the item I was not given an estimate on the delivery date

Had difficult to find parts.

Share icon
Return Policy
Returns are easy at Boatplicity

Not happy with a purchase? No problem. We've made returning items as easy as possible. And most purchases can be returned for free for 30 days. Learn more about our Returns Policy