Do the 400ex respond well with this upgrade ? How do these engines hold up to the 440 bore (crank failure..etc..)? Due the engines tend to overheat with a big bore ?

What kind of HP (RWHP) can I expect with the 440 kit/cams/exhaust/jetting, without any headwork (no porting) ?

Would that be enough to run with an LTZ400 in comparison ?

Thanks in advance

 

i would say it would be able to keep up with an ltr 400 to make it beat it without a doubt get a stage 2 hotcam it helps bring out the top end what you going to get is a lot of low end torque my buddy has a 400 with stage 2 cam 440 kit 12.5 piston and port and polish and it has awesome low end torque but starts to fade towards the top end

 

My friends with 440's end up with lots of problems! At that point, the legendary EX reliability is completely gone.

If you need a rebuild, I would go 416. If you are looking for more performance, step up to a 450.....

 

Agree with recon. Go 416 maybe 426. Wouldn't mess with 440.

 

OK thanks.

 

You asked about the Z. The EX has bottom end, where the Z likes to rev on top. So, the Z has a faster top speed so I like it for open country, where the EX makes a better tight trail quad. Have not ridden the new fuel injected version, however. As I recall, the FI version is rather heavy for a 400.

 

The 09 Z may have bottom end power similar to the 400 EX, Suzuki claims to have tweaked the engine and its fuel injection mapping to increase low and mid range power over the carbed version. Also the weight increase between the 08 and 09 models is due to Suzuki listing the wet weight of the machine will all fluids (engine oil, coolant, and a full fuel tank) instead of the dry weight. The 09 Fuel Inject Z400 probably weights about the same as the 08 carbed machine.

 

ii've heard that with the 440 the ex can have more head gasket problems (blown head gasket) i read this in Atv sport magazine.

 

happy 1 year anniversary!

 

Haha, almost to the day!