Hello I was wondering what is the best mods to get power out of a ltz400 which is stock what intake is best? Jetting? And what exhaust is best that is loud and nice sounding? Any advice appreciated

 

Welcome to the forums.

When I had mine, it seemed Yoshi was a pretty good exhaust system. Loud doesn't mean better. Air filter is a debate over K&N and Uni, among others. Jetting would depend on what you did with the first two.

Those will get you some increases, but if you really want to increase the numbers, you're going to have to go inside the motor.

 

I will be going into the motor a but closer to winter when I won't be riding want to have it the best before I do it and what would you recommend when I start to tear down the motor?

 

If I had the time and money, I'd go with a big bore kit.

What year model is it? Asking because first year models had some frame issues that would definitely need to be addressed if you're going for more power.

 

It's a 2007 model I knew about the frame issue and wait till I could get a newer model what sort of power would you get out. Of a big bore kit?

 

This article is from 5 years ago, so keep that in mind. They went with a 434 kit, but they make a 490 kit too. Kind of an idea of what you might expect to gain.

 

I Will have a look into it cheers thank you for info

 

There are plenty of motor builders out there. I'd ask them. Mickey Dunlap's "4 stroke tech", Curtis Sparks, Baldwin motorsports, TC Racing and others.

 

I've currently got one in for a motor build that has a snapped chassis!

Running a big bore kit but it has had a hard life, Ripped the wrist pin straight out the piston and smashed the cylinder.

 

The best set up is the 416. It's dependable and fast. My daughter took 2 national championships on a 416.