Bad Boy Zero Turn Elite Valve cover leak repair

Over the last mowing season I began to notice my riding lawnmower always smelled like oil and there was always a sheen of oil around the muck on the base of the engine. A closer inspection of what was “wet” revealed the left side valve cover to be the most likely origination point for the leak.

Wet “sheen” of oil on bottom of chassis.

So I’d decided to further confirm my theory by removing the covers to take a close look.

Removal of rear shroud. Note hydraulic tanks must stay elevated to keep from leaking.
You can see on the bottom left screw hole where the gasket was leaking. There is a charred / stained area from the leak.

Clean off any remaining gasket material from both the engine and valve cover mating surfaces with a soft bristle brush.

Check “flatness” of removed valve cover mating surface by placing it in glass. If you can’t slide paper under it you can reuse it.

Make a new seal around your valve cover and then follow the torque instructions on the sealant package paying special attention to the cure time before final torque.

In using my torque wrench for the first time in a long time I was pretty surprised by how gently these cover bolts needed to be torqued. It would be very easy to over tighten this warping the metal and causing more leak points.


I put the mower up for the rest of the season but just got it out last weekend. I mowed 3 acres! No leaks! Another one done. Next time I think I’ll do both valve covers at the same time while I have everything apart.

Note engine manuals are pretty awesome documentation. Find yours online and save a link to it in your smartphone.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: