[batgeek_KFX400]

replace base gasket(the gasket under your cylinder) with one from the DRZ400 dirtbike not the dualsport, the offroad only model. get ya ~6hp gain for cheap
running thinner gaskets whether base or head gaskets will increase your compression ratio by moving the piston closer to top of head. The tighter squish you can get; the more power you can make.

- all this was cut and pasted from nice folks at atvNC.com .

 

[Corpsie]

Got a dyno sheet to prove it?

Do you still run 92 octane or do you have to run something higher?

Also, does it affect low end torque?

 

[Tainted Glory]

thanks for the tip. you wont have to rejet right? the theory behind this mod makes sense-im surprised noone realized it earlier.

 

[KFXRida]

Is it easy to replace the gasket? I am pretty mechanical, but can't do everything. How much teardown is required?

 

[fastmike926]

Changing the base gasket wont give you a 6 hp increase, it will bump compression, and make the bike hit a little bit harder though. I have done all of the Dirt DRZ mods to my DRZ400s (same engine as the LTZ) and have gained 10 horsepower, without decreasing reliability. To get the 10hp I had to switch the: Carb to a FCR39, base gasket, dirt cams, Yosh exhaust. The dirt DRZ puts out close to 40 hp, mine puts out 43 hp. The base gasket mod was barely noticable. The FCR made the biggest difference, next would be a stock carb with a dynojet kit, followed by the Yosh pipe (If the LTZ has the same head pipe as the DRZs it is 5mm smaller than the dirt DRZ, and 7 or 8 mm smaller than the Yosh headpipe) so it was pretty restrictive the cams were the next biggest gain, followed by the base gasket. I did all of the mods one at a time so I could tell what worked best.