Good things to know about your ZX7-R

whitehendrix · Fri Mar 07, 2008 8:50 am

i just would like to share some info about the 7R that i've learned from servicing them and owning one myself. this is mainly based off the '96-'03 models, consisting of the N1, N2, and P1-4 bikes..

-the bikes run HOT! often you'll see a bike with a partially melted, stock plastic fan. when it melts, it'll lock the fan motor up and blow the fuse, usually causing more electrical problems along the way.
Muzzy makes an aluminum fan blade assembly, or you can just wire up the fan to run all the time when the bike is on.

locked-rotor current is typically 5-10 times what the normal running, full-load current is for any electrical motor.

- these bikes are an electrical engineering nightmare! (at least to me, being that that is what i do..) all the bike's current goes thru the key switch. your bike will typically pull around 15 amps when running and everythings on. the thing is, the switches and connectors are slightly underengineered, and their ampacity (current rating) is lower than what it should be.

- your ECU has a reduced voltage input from a resistor in the key switch's contact block. if that resistor burns up (common, unfortunately) you'll have 12 volts everwhere, and no power on the gray wire from the keyswitch harness. that gray wire has less than 12 volts on it (theres exactly 6 volts on it.).
this will cause you to
*not have fuel delivery, (the fuel pump is powered from a pulse fed, SCR "relay". the pulse is source from the #1/#4 sparkplug coil.),
*no spark
*and the bike will have power everywhere, but won't start.

- the motors are noisy by nature, and if it slightly resembles an idling diesel, its not the end of the world! you probably just need a valve adjustment.

- if you ever get an e-bay motor, run the engine number thru your local popo. they'll tell you if the number comes up on their system as belonging to a stolen bike or not. you don't have to tell them you already have the motor, just say you're looking at one on the computer and was curious about it before you bought it.
i know a dude that had his whole bike taken by the pigs cuz the motor number came up hot. the bike, (a stunter 636) was fine and legal, but his e-bay motor was stolen, and he didn't know it. when the man blew up the stunt spot, they ran everyones numbers and his shit was seized.

- the '94's flatside carbs are jetted horridly lean from the factory to meet epa regulations, but make it vicious on the track. thats why they suck under 4000rpm.

-the little black junction/fuse box under the seat contains two relays on a printed circuit board. one is the headligt relay, and the other is a relay the operates the starter solenoid. this little relay will not always work, and when you push the start button, the bike won't always start because of it. i'm working on a cure!!

-these bike ARE equipped with a slipper clutch!!

- i think thats about it.. i cant think of anything else, but if theres something i missed, let me know!

be safe and have fun!

Good things to know about your ZX7-R

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