Mouse smell in tractor

[carwashguy]

My father passed a year ago and I’m slowly taking all of the tools from his house including his lawn tractor. It’s in great condition because he barely used it. It sat in that shed for a couple of years. There was some evidence of mice living under the hood but no damage that I could find. I think there was also a nest in the muffler.
I’ve washed it down but every time I use it it smells like dead mice. Is there a way to get the smell out? It’s been in my shed for over a year. I’d suspect that any dead mice in the exhaust would have burned up and and decomposed enough to not be an issue.

[barnowl]

My father passed a year ago and I’m slowly taking all of the tools from his house including his lawn tractor.  It’s in great condition because he barely used it.  It sat in that shed for a couple of years.  There was some evidence of mice living under the hood but no damage that I could find.  I think there was also a nest in the muffler. 
I’ve washed it down but every time I use it it smells like dead mice.  Is there a way to get the smell out?  It’s been in my shed for over a year.  I’d suspect that any dead mice in the exhaust would have burned up and and decomposed enough to not be an issue.

If there's an air cleaner/filter, check that. 

Mice built a nest in my motorcycle filter once. 

Also check the foam in the seat.

[MstrCarpenter]

I would start by removing the air shroud on the motor. Lots of places under there for mice.

[Wild Turkey]

Park outside on sunny day. As suggested remove all covers, etc.  Apply leaf blower, etc. liberally to all cracks, crevices, openings, etc.  

Heat and fresh air may take care of problem.

Big problem is mice pee on their nesting material so even if you get the material out the surface under may be soaked/cacked with dried urine which may need to be flushed.

Good luck.