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Discussion Starter · #1 · (Edited)
READ: Good things to know about your ZX7-R

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 P1-8 bikes..

these bikes HATE TO START HOT!!. they vapor lock. its a fuel system design flaw. a little bit of heat shielding around the fuel lines ( and if you want, raising the float height a bit) tends to resolve this. if you get stuck somewhere on a hot start problem, remove the seat and let it sit.. removing the seat lets some of the trapped heat out from under the tank.

the OTHER hot start issue is low voltage to the starter solenoid. usually about 7 volts or so. it's mainly the wiring and being a piss-poor design.. sometimes voltage can be brought up by cleaning the connectors where the handlebar controls plug into the main harness up by the forks. most times you'll find corrosion there.


-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. (fan pulls 4.3 A)

- 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 CDI has a reduced voltage input from a resistor in the key switch's contact block. if that ( 100 ohm) resistor burns up or the wire's solder joint snaps loose (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. it will crank, however.. all day.

- 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 or need to bump the CCT out one click.

- 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 '96's (RR model) 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.


-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!

i'll list a few common numbers, i'll put more here in time.

Battery, electrical, fuel, ect..
N model:8 amp hour,
P model:10 amp hour

alternator: 14.2-14.8V @ 4000rpm , 30.6A @ 6000rpm
pickup (trigger) coil resistance: 375-565 ohms (typically 460 ohms) (good for ALL ZX bikes with CDI)
primary winding resistance (sparkplug coil): 2.3-3.5 ohms
secondary resistance: 12k-18k ohms

fuel pump pressure:1.6-2.3psi (good for ZX6/R, 7,11, ZZR)
fan ON temp:199-217*F
fan OFF temp: 196-203*F

Fork oil level: 110MM from top +/- 2MM
Fork oil capacity (dry): 495mL +/- 4mL
top cap torque: 11 ft-lbs
allen bolt torque: 29 ft-lbs
stock viscosity recommendation: 5W kayaba oil.. 10W will work fine tho.

ignition info..

black lead:#1/#4 coil
green lead:#2/#3 coil
red lead: both coils GREEN TERMINAL!!!! very improtant.. backwards and you won't have spark.








be safe and have fun!

useful links
"frenching" the taillight (flushmounting..)
http://www.kawiforums.com/zx-7r/129995-how-french-tail-96-a.html
 

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i have the same problem sometimes trying to start it and my bike starts to over heat when i ride in the city on a 90 degree day in stop and go traffic but im going to flush it and see if that helps
 

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Discussion Starter · #5 ·
i think i can get solid state relays in that footprint from a local supplier.. if i cross ref a compatible relay, you guys will be the first to know, and i'll either do the conversions (after i test mine out, of course make sure it won't fail..), or sell ya a blueprint/schematic.. or just send it to ya if you know any hot chicks that like ugly kids and the hookup works.
 

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great info but i was wondering if it applies to all model years. I have an 01 and i haven't had any problems with it so far. the only thing i notice is that sometimes after a ride when i shut the bike down the fan kicks on as i'm walking out of the garage. is that normal? can that wear down my battery?

edit- I'm still new to riding so if these questions seem dumb please don't hate.
 

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Great write up. I had the difficult starting problem too. Turns out it was the +12v wire to the ignition had slowly desoldered itself. I was worried why but your explanation about the electrical system being underrate explains it perfectly. Ever since I resoldered it and replaced the battery it fires right up now.


PS I remeber having to pop the front seat and tap on the headlight relay to get it to start sometimes.
 

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New Zx7r Owner

I just bought a 99 model zx7r with only 5750 mile on it....ibought it with out hearing it run carbs where shot had to be clean out.got it running to night.(YEA)
But would like to know if there is any secret mods that can be done....As far as i know it only has a wileyco pipe on it,and rest is stock....Any info would be great Thanks:confused:
 

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Discussion Starter · #11 ·
sweetzixxer: LOL.. no hate at all bro!! the fan is operated by a round switch on the clutch side of the radiator.. when the coolant is flowing, the heat level stays low due to the transfer of the thermal energy from said coolant to the rad core.. when it stops (when you shut her down) this transfer stops, and the temp raises... it doesn't have the chance to cool off, and the heat "catches up" with it. if you have a shitty battery, it'll kill it, but it'll only run for maybe a few minutes before enough heat is drained away to open the switch up and kill the fan.

cuseballer1474: no sir, theres nothing thats specific to the year thats problematic.. its usually all when the first gen comes out.. like with the '01-02 GSXR1000 & 600... they had alot of trans trouble, particularly in second gear.. it was all rectifed by late '02- '03.. i can't remember, but i think it even warranted a recall...

DWH_ZX7R: theres some slight-power type old skool shit you can do.. blocking the vents off at the top of the valve cover is said to produce more power.. how much and where in the revs? i honestly don't know... sorry! but ignition advancement, jetting/carb shimming, and full exhaust can put the bike over 130 CHP.

oh.. and Supa, dude. you're right on. i had the that lil gray wire that feeds low voltage to the CDI come unsoldered last summer... baffled me for a bit til i remembered about the whole resistor-in-ignition-switch thing. when i was test everything, i metered 15A of current going thru the white supply wire to the witch.. thats WAY too much for that gauge of wire, and the wire was physically warm... thats why alot of the times, you'll see cripsy plugs on these bikes.. my ignition switch plug was melted, the alternator plug... melted.. i am gona put a relay in the bike very son.. the relay will carry the load of the bike's electrical shit and keep the switch from doing it... if you guys are interested in this, i'll do a writeup when i do the wiring change.. i promise you won't need an electrical engineering degree to decipher it.. i'll keep it simple!!

thanks again for the good words and all everyone!!

be safe and have fun!!
 

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Hey whitehendrix...is adjusting the valve on the 1999 ZX7R hard to do or should i let a shop do it.i work on cars as a hobbie but really never mess with to many bike.so i dont know to much about them.reason i ask is because when i start it....it has some nosie in it sounds like valves to me..when i give it gas it kinda stalls for a second or two till it around 2500 or 3000 grand then picks up quickly...
Thanks for any info....:confused:
 

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thats great info WH!
if you did a writeup I would surely use it. Especially if it had pictures! ha
I know simple electrical stuff so it will be easy for me
I dont think we have enough writeups on mods.
I really havent seen much!


thanks
 

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Discussion Starter · #14 · (Edited)
DWH: i just posted up a valve job for the other guy.. i forgot his name, but its all there.. i will try to get pics to go along with it in time..

the setup is whats called "shim-under-bucket" and consists of a small shim that sits on top of the valve stem, held in center by the spring hat, and the spring and shim are capped by a precision-ground "bucket". the cam rides on the outside surface (what would be the bottom of a real bucket) the shim is captive when the bucket is in place, and only transfers the axial force from the cam lobe directly to the valve stem.
the stuff you've seen is probably the 10MM jambnut/ allen screw type shit on hondas and other japanese cars.. i work on those, too..lol

these bikes are really noisyby nature tho, but you should be able to use good judgement in determining whether its a valvetrain problem, or just normal noise..

as far as the stumble, that sounds like fuel.. does it do it when its cold? how about rollin on the gas slowly.. does it follow with linear action? if its sputtering and ackin stupid, i'd at least go for a plug change first to rule out the simple shit, then start to play with the fuel system.. could be slightly out of sync, or is having trouble switching from low to high speed fueling circuits in the carb... plugged jet.. something like that.




EZ: i'll definitely do a how-to on that shit man.. i don't like the fact that soo many of us 7-R owners are riding on something so problematic with the electrical system...
i'm tryin to put forth some good shit on here, but i have to be careful of what i post as well it seems... i can't post anything copywrited like manuals.. i'm not sure about indiviual pages, or modified pages from a manual, but you know i'll figure something out with it!! my biggest problem at the moment is fiding time and whatnot to do everything.. i'll get it tho...
 

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copyrighting infringement is the stupidest BS I've ever heard! ha
I think that as long as you cite your sources there should not be any problem...

as far as the "buckets" I'm guessing thats like a valve spring hat or something?
I've changed valve parts on cars... upgraded springs... etc
I dont see why you have to get a valve job if you mix up your valves/heads... I would think it would just wear itself in, but I guess I'm wrong.
Do you have pictures of these mystic fairy-tale "buckets"? If you cant post here then please PM.
thanks alot
 

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If you guys want to get a whole lot of info on the 7r, search for the red monkey 7r site. There are a few things we can do to our bikes to make gains that are cheap or even better yet free. Here are a few of theings I have done : float bowl mod(warning to all you guys on the CA emissioned bikes it will cause a huge flat spot before 3K rpms, solution is to get a 49 state CDI module), removed the screen from the airfilter, CR9EK plugs from a sukzuki, timing advancer, and full synthetic oil. Doing the float bowl mod must have saved me 5 lbs from all the crap I removed. The most expensive part I have on it is the D&D can. I got nearly 40,000 miles and it still runs strong as ever.

Whiskey Hotel(White Hendrix): I thought about putting a relay inline too but my solder job should last for the rest of my bikes life. I don't know what kawi was thinking with that small gauge wire and 15 amps running through it. That also explains why when peeps put the brighter light bulds in the head light sockets desolder themselves. One of us should do a write up on how to resolder the key switch since its a little tricky to get into it.
 

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that key switch, so that's what it is! damn, that problem has been giving me so much headache! i basically have to bump start it half the time. that makes so much sense as to why my 7r wouldn't start a lot of times when its hot. i think i'm not the only one who'll be extremely grateful if one of you did do a little write up on how to remedy this annoying problem.
 

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DAMN! I thin i just fell into this situation. my bike left me sittin in the wendys parking lot tonight looking stupid and freezing. bike was running fine. i shut it off, went inside for 20 minutes and it wouldnt start. kept turning over but no start. i should have smelled fuel cuz i was working the throttle but didnt. waited 15 more minutes and it started right up.

am i right in assuming i got the "Ignition Grey Wire Syndrome"?
 

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Sounds like it, try a new battery first, then if it still does it remove the bottom cover of your ignition switch. Be careful lots of little parts and whatnot.
 

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Discussion Starter · #20 ·
supa: thank you for the kawi mod site bro!!!

good shit..

nandez: man my shit never restarts when its warmed up.. i gotta find a cure for that.. it may be float related..

ez: my man.. i'm tryin to get this "new" motor (for the turbo build) to the house, and i promise to get pics for ya and go into explicit detail on this..
the "buckets" literally look like little metal buckets. they sit inverted and cover the retainer, shim, and about 80% of the spring. a pic of this actually is in the drag racing section in Denmah's "turblo" post.. those shiney round things in the head are the fables buckets i speak of sir.

fellas, alot of the time the bike just clicks and doesn't do anything, its the "reed" relay in the lil black junction box under the seat. the ignition switch rarely goes bad, but the relay in that box tends to go after a few years of service..

the resistors do burn up in the switch tho...

the 5 or 6 wires that run into the ignition switch are 100% indeed soldered, and i had my lil gray (low voltage) wire break off, causing erratic operation.. sometimes, just by turning the key, it jarred the wire into place. for the longest time. i could not understand why i had power everywhere, but had no spark or fuel, but the trigger coil and spark plug coils were good, but my 6-E's ecu wouldn't work either (the '93-up ZX6-E CDI works on the 7-R.. how well, i don't know, but it will run and rev..) .. the fuel pump runs off the #1/#4 sparkplug coil pulse.

like i said, the wire has less than 12 V on it. it the power comes in on the white wire, thru a set of contact, thru resistor inside the switch body, then to a solder post that the (gray) wire is connected to..

should you find this is whats fuct up, use an impact driver (trust me..:D) to remove the main mounting screws for the switch, remove the switch assemble, and take out the two tiny screws holding the shibang together and peel the switch apart. note the orientation of the contact blocks!! the stationary contacts can be put in upside-down.. the moveable ones also.. but theres only contacts on one side, and its keyed.. it's pretty much fail-safe.

If, the screws are snapped off (most bikes left kawi like this.. the screws are "anti-theft") take a dremel with a 1" cutoff wheel and make a slot dead-center in the screw.. just big and deep enough to get a flat screwdriver in and twist the screw out. they're not loc-tite'd like the main mounting screws are (thus the impact driver) a 3/16" flathead is usually thin enough to get into the slot provided by the wheel.. its only maybe .02-.03" big.. if that..

as far as a writeup, i'll gladly repeat this in its own thing if you'd like to see it separate from this.. i'll try to include more retails as well.. i'm just doin this shit outta memory at 5:30am...

i will start on finding a cure for the relay, as well as making custom parts (like 2 piece pegmounts with c.f. heelgaurds) and ignition advance plates and some other shit for performance.. i will be ordering a "rotary table" for vertical milling (so i can make the stock cam gears adjustable) in about a week or two, after my new set of Mitutoyo 6" dial calipers shows up.. (for machining)

gotta watch the finances, i got mad fines and shit to pay to keep me out of jail for stuntin the fiddy last summer on the streets...:(

i'll try to stay up with ya's.. i get 1000 things going at once sometimes and i neglect my kf bretheren, and i apologize. i'm just glad i can offer some help on this.. it does me good to know this shits useful!!
 
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