After you get the head shaved down .015 at a machine shop... Reinstall the head back on the bike, now there two pins that hit the rocker arms that are attach to the top of the valve springs... Now get a "spark plug gap key" and stand the bike up. Now look through the spark whole where it screws back into the head, pull the pull-start on the bike until you see the piston at its highest point. Okay, almost home loosen the bolts on the rocker arms, and adjust with allen key and your gap key... You should be able to slide the gap key between the rocker arm and top of the valve spring. There needs to be very little tension you should be able to slide gap key in and out...

The person told all this and the machine shop it was my first time, it was easy and straight forward... Maybe I was supposed to do something different but I don't think so... When tried to turn on the bike after everything she fired right up with 1 tap of the start bottom. I haven't had problem with the bike since and I know this is 1 of the fastest ltz50's out there right now......

 

Someone in an earlier post mentioned that their bike was not hitting the rev limiter with a 48 tooth sprocket. We are not experiencing that problem at all. Our gets there easily.

 

EDC....changed the spark plug to a non resistor plug.....stock is ngk cr6hsa and the replacement with the nology wire is ngk c6hsa the nology wire has the resistor built into the capacitor in the wire itself.

now the dr. pulley sliding weights are the best thing since sliced bread. look up union materials in the search engine. the variator weights slide instead of roll and they have a ramp shape to them. i ordered online from indy cycle ranch. the ltz50 takes a 17mm x 12mm thats the physical size of the weights, i ordered from indy cycle ranch online......they say on the web site there is a minimum of a 25.00 order just call them and they order the people are real cool.

basically instead of putting stiffer springs on the rear clutch shoes to raise launch rpm i just machined the shoes to lighten them.....i went to 200 grams because i didnt want it to launch at to high an rpm ( its raced but it still gets ridden around the yard).......for a killer launch its recommended to machine them down to 180 grams

and with the porting i left the stock exhaust port alone on the intake side i smoothed out and blended in the real sharp lip on the port ceiling ....its left over from the factory machining..... is it worth it when the head was off for machinig yes, i dont know if id recommend yanking the head again for just that.

 

<div class="FTQUOTE"><begin quote>Originally posted by: EdKatt

Hey JPL, are you running the Duro Knobby's?</end quote></div>

yup the rear are knobbies look just like holeshots..... square edge tire, real stable and will just hook and drive though ruts. the front are ***** but are directional for quick steering / handling.........................these tires are GREAT and its not easy to find a good tire for our 7 inch rims

 

monday
I'll shave the rear clutch too 200grams.
order the new tires and buy that NGK plug c6hsa
Do you have a part # for the plug WIRE ???

 

how do you lighten the rear clutch? What kind of difference do the nology wires and plugs do what kind of $$

 

The stock wire has a resistor built into it you can remove it and install a solid little bar stock or anything round. Look in the spark plug boot you will see a screw to take out and behind that is the resistor

 

so kingquad are you saying the nology wire isnt necessary just modify the stock one and if so what did you do and what difference did it make. The cdi unit should be coming soon is there anything i should take care of rite away after putting that on besides maybe air fuel & idle adj. I plan on the jets and shave i already milled the rollers in the front clutch took out two rollers worth of weight is it worth it to get new rollers and mill the rear clutch i also plan on the 48 tooth sprocket.

 

Hello all,

Does any one know if the cdi box from CT racing works well for the Z90? They tell me it is the same one for the Z50 but has dipped swithes to change it up for the Z90. Do you need to re-jet after you install the cdi? Daughter is getting tired of this thing dragging butt and need to get some more top end out of it. Any help would be appreciated.

 

Im sure it will work fine. You shouldn't have to rejet.