The Z400 quad gets the milder 11.3:1 compression of the DR-Z400S Dual-Sport motorcycle (so the dual-sport can use 87 ocatane gas.........who cares??), rather than the 12.2:1 of the DR-Z400 dirt bike. I presume this is just a move to detune the engine further for quad use? So what is involved in upping the compression? A piston change? I presume the engines also have different cams? Anybody done this???? I frequently ride at higher altitudes, so increased compression should help, right?

I notice also that the DR-Z has a larger 39mm carburator. What all does it take to get the Z400 up to DR-Z400 specs????

 

Yes you can get the DRZ base gasket for around $20 to up the compression to 12.2:1. I needed a new piston which is why I bought the Wiseco. The cams are also different but if you decide to get new cams, go with the HotCams. Not sure about the carb, so let us know what you find!

 

It occurs to me that the dual-sport bike has to meet street legal emissions, hence the lower compression. Why strap the quad with this handicap? I presume the DR-Z400 gets a green sticker with no problem?