i was looking at buying a high compresion piston for my z400, and was wondering what is a good compreesion to get, are there any problems with them, and what type of power you get out of just the piston. Also would i have to buy a cam to match it or not?

 

I would try a drz 400 piston, its a hight comp than the ltz, you will still get the reliability of suzuki with something made by suzuki for that motor.

 

so can i still put in just a higer compression piston with out hurting anyhing and not have to put any other parts in it?

 

Compression is where 4-strokes make power. It will give you an increase all across the rpms. You don't need cams to match up with the compression but you will be a lot happier if you do decide to go with cams. There are a lot of different grinds to choose from so do some research. Web, Yoshi, Mac, VCP and HotCams all have different grinds for the Z, some even manufacture multiple grinds and stages.

The DRZ is the exact same piston as the LTZ. The difference in compression lies in the base gasket. The DRZ gasket is 1 layer, the LTZ is 3 layers. Purchase the DRZ-E base gasket (~$15) and that will bump the compression from 11.3 to around 12.2. The DRZ has dual rate valve springs as well. While you're in there doing the base gasket you can swap the valve springs. These will be a necessity if you plan on running any higher lift cams or an aftermarket rev-box/CDI.

If you're just replacing the base gasket or upping the compression using an aftermarket piston (these come with the thinner base gasket as they were meant for the DRZ anyway) then all you really nead to do is re-jet.

Also, a full pipe is really needed to get the potential out of any other mods. The stock head-pipe restricts power above 7k rpms.

 

just remember that anything over 12.1 in compression you need to run a different fuel, higher octane
if you dont you could have detonation knock and you dont have to have cams but it does help

 

^^ Nice catch there Mucky, thanks. Most guys claim no problems on 91 octane w/ 12.2:1, I run 93 for peace of mind.

 

I have to run a mixture of 91 and 110 fuel in mine
50/50 mix

 

get this right, all i need to do is put in a drz-400 base gasket and my compression will boost up to 12.2:1? And also do you know any other people that jave done this?

 

Yes you are correct, it bumps compression up 1 point. Make sure you get the gasket for the DRZe (add the e) bike. One style of the DRZ bike has the same base gasket as the Z.
A lot of people have done this, including me. I also installed hotcams at the same time as the base gasket. There was a very nice gain in power. Best price I found on hotcams was from woodwardspecialties.com. Im also running 93 octane gas with my mods.

 

thanks, i guess i will do that.