I purchased a 2000 honda 400 ex this weekend. being that the first the atvs i bought were this weekend i don't know much about it. so i have a few questions hopefully you guys could help me with. first the guy i bought it from was telling me something about it was bored out to a 440...?? could someone explain that further for me? also, what is a good website to get replacement tires, wheels, and other atv parts of my honda and also have a polaris. any help would be appreciated, thanks!

 

**also what are some basic maintenance that i can do regularly to keep her running for a while.

 

i hear the 440s have a lot of problems breaking head studs and running hot and blowing head gaskets.save your money for replacement parts

 

Inorder to get a 440 from a 400ex you have to have the cylinder machined and install a new cylinder sleeve and bigger piston to bring the displacement up to 440 cc's.
The 440's have a tendancy to blow head gaskets because if they are running a higher compression piston, 12.0:1 or higher, they can stretch the head studs (bolts) and blow the head gaskets. This can be alleviated by having larger head studs installed.
You really need to know what compression the bike has. You may be able to call the previous owner and ask him these questions. If you are running above 12.0:1 you will also need to run a mixture of race fuel and pump gas.
You cna get parts and tires from: rockymountainatv.com or denniskirk.com

 

I had a 2001 440EX and it went through head gaskets and leaked oil like crazy, i finally got tired of installing new head gaskets and fixed it the last time and sold it on EBAY for $2025.00

 

i saw in ur sig that it was ur wifes atv.. thats gonna be a fast one for her! yeh u can buy parts off of ebay, rockymountainatv.com,denniskirk..