help im out of ideas

[fasstltr]

i have an 04 z400 it wont start so i checked spark thats good i had to shim valves those r good now timing is good i changed the gas nouthin so i bought a compression test and it was 30 psi which i no is no good so i tore the head off and the cylinder is clean the headlooks fine i pourd water in the intake and exhaust of the head and nouthin leaked im confused i think either i need rings or head gasket any help would be apprieciated

[fasstltr]

anybody have an idea cause i need help

[sprocket226]

Well since you've gone that far, might as well put new rings and gaskets in to get your compression back up.
I'm not sure if the Z's cylinder has to be prepped for new rings, maybe a Z400 engine guru will chime in here and give ya more help...

[ltz440rider]

also check your cdi box make sure thats plugged in.

[fasstltr]

i have spark

[samz]

I agree that you should go ahead and put new rings in and a gasket since you are already there. The low compression has to be one of the two. You don't have to prep the cylinder unless you have gouges in it and if you do you should think about a big bore.

[maxitout77]

Do the rings and gasket while you are in there, at the very least its not very expensive, and if that does not fix the problem, its one less thing you have to worry about down the road.

[fasstltr]

well im going to just buy an aftermarket piston probley wisco but should i go with the 13.5 to1 piston i heard i could use 94 octane with the ltz base gasket is this true need to no by fri day magic racing is like a 1/2 hr away from me

[zracer16]

Yes, if you go with a 13.5 piston and use the stock base gasket, that will put you at around 12.6 to 1, which allows you to run on premium pump gas.

[fasstltr]

k well i got the 13.5 to1 piston and that was it now i have 160 psi compression .my stock pistons rings didnt even stick out past the piston.the quad runs great