My Account
Shopping Cart

Shopping Cart

0 items in your Cart
View Cart
Subtotal
Track
My Order

Sierra 18-99128 Exhaust Inner Cover Gasket for Yamaha 2-Stroke Outboard

Manufacturer

Picture for manufacturer Sierra

Part Number

18-99128
12 reviews
Sale Price

$11.69

2 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 18-99128 is a precision-engineered aftermarket exhaust inner cover gasket designed as a direct replacement for Yamaha 2-stroke outboard engines. This gasket seals the exhaust inner cover on the cylinder and crankcase assembly, preventing exhaust gas leaks that can cause overheating and power loss in marine applications.

Sierra gaskets are machined to precisely match head and block surfaces, giving both professional marine technicians and DIY mechanics the confidence of a correct, leak-free seal on the first installation. As part of Sierra's extensive marine parts catalog, this gasket is engineered to meet or exceed OEM specifications and is built to withstand the demanding conditions of the marine environment.

Key Features:

  • Direct OEM replacement gasket for Yamaha exhaust inner cover
  • Engineered to meet or exceed Yamaha OEM specifications
  • Precision-machined for accurate fitment to mating surfaces
  • Designed for 2-stroke outboard engines (50 HP, 60 HP, 70 HP)
  • Backed by Sierra's Limited Customer Satisfaction Warranty

OEM Cross-Reference:

  • Yamaha: 6H3-41112-A0, 6H3-41112-A0-00, 6H3-41112-00, 6H3-41112-01

great

After searching online I found the best price with free shipping here. Fast shipping and easy installation of my product.

OK, but shipping cost not determined until after processing to paypal.

Very easy so far.

great price

Found the K&N filter for my 2012 Acura TL at Autoplicity for the best price and delivery took about 2 business days. Can't ask for more.

check out was easy

The Parts that I needed at a great price.

So far it has been pleasant. Easy to maneuver website.

fast...easy

Great Company. I needed a part quickly and for the right price. They had the best price on the internet, and made sure it got to me in two days before I went away on my road trip. I spoke to a representative that was very helpful. I highly recommend Autoplicity! Thanks!!!

easy check out options

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