94 zxr750 Won't rev

[Gav]

Souds crazy..Check you haven't over filled your engine oil...

[willrcr15]

Well that didn't work, I just put the vent crap back on & no difference !
The engine oil is in between the lines, It did take more than specified initially but it's on the mark.
Looks like another weekend studying the fuel flow system & the diaphrams & vacuum function.
Dads coming down this weekend I might lock him in the garage with it & just poke food under the door till he works it out.
Signed
Very degected

[NINJAINOZ]

Lots of people have put in some ideas but very hard to diagnose through text, Maybe get a video of it running & some pics to show how & where you have routed the float bowl vent hoses?

Does it idle OK? Does it have any flat spot when you rev it? Can you rev it hard from the bottom/idle without it hesitating?

I will send you some links to read through too

[hipstir70]

As Ninjainoz said its hard when we carn't see or hear the problem, if you can pictures of how the carby vent routing on your bike. You can only go through the basics 1st. Hopefully it's something simple I sure someone will help point you in the right direction.
Cheers Rob.

[ajverma]

Check your sidestand switch

Does it rev cleanly and smoothly to redline while in idle on its stand?

How about off its stand?

Also check your petcock, could be faulty, aren't these bikes notorious for petcock/tank issues?

[willrcr15]

Thanks Guy's,
I haven't revved it more than about 10k on the stand but it seems good at that, no hesitation.
The petcock has a new kit in it, the old one leaked.
It idles perfect.
Doesn't get hot on the road, just sits on 1/4 to 1/3 mark.
With the evaporitive stytem disconnected the tapered tube was just left open to the atmosphere. I put it back on last night as per standard setup, thats connected to the tapered tube with the valve system bolted back onto the frame in the rubber damper & the outlet routed into the side of the airbox, there is a skinny tube from the valve assembly that I cant see where it goes so just left dangling, I blew & sucked on it but it didnt do much, figured it was just a vent or drain. Does it connect to the opposite side of the box on the small nipple, or does it connect to the inlet manifold vacuum nipple ?
We'll find it sooner or later, just didn't expect this sort of trouble, it's all in such good condition.
I'll check the jet sizes again to make sure they're standard, I expect they are & I think I remember already checking.
I can't stop thinking the slides arent lifting & raising the main needle. Riding along to about 3k rpm alls good but if I open up the throttle she chokes & there's no recovery, If I open her up carefully from the 3k rpm I can manage 5k but thats it there's no more even dropping down the gears she'll rev up between gears on the clutch then nothing when engaged. However she usually gets up & goes in first & second gear, it's not perfect but I can see about 10k.
Thats what I mean when I say it could be electrical as it breaks down under load, BUT why does it respond to the choke in 3rd & 4th gear up the hill. That is while it's choking & coughing I drag the choke on & bang away she goes clean as a whistle.
Thanks for the help.

[NINJAINOZ]

If you need the choke then it is certainly lean, Try some #40 pilot jets

The way my bike ran when I bought it I originally thought the carby inlet rubber manifold/mounts were buggered & I planned on replacing them but after getting the carby's sorted much better than they were my bike pretty much does not need the choke at all, Except for maybe real cold mornings
Basically as shown/written in the links I have sent you the float bowl vent tube needs to be routed into the airbox in between the filter & the carby's, I have seen some guides that mention running the vent hose up to the front of the airbox before the filter, If you happen to ride down a dusty road the fine dust can go straight down the vent tubes & into your carbys & clog them up then down into your bores & rings/pistons & prematurely wear them out which would not be real nice, Just the general fine dust in the air would not be nice going down the vent tubes over time

Here is a pic of the carby float bowl vent tube to show how easily I have routed it into the airbox>

I will tidy it up later on with a piece of steel or plastic elbow of some kind but it works great as is & it can be removed/unplugged with the airbox on the bike & I dont have to stuff around running hoses up into the bottom of the airbox when I need to remove or fit it back on

[ajverma]

Checked your charging voltage at idle? Check it at 5000rpm?

You sure when you cleaned out your carbs you put the pilot screws back to the original settings (or nearby).

Friend rebuilt his carbs and was wondering why the bike was running like crap, went over the carbs again and he had tightened the pilot screws down all the way... bike didn't want to rev at all

[willrcr15]

I'm electrically handicapped, I'll try & test it with a meter & see what I get, 12v??
The battery gets a workout upon startup when the bowls are empty, maybe 20 to 30 seconds on the starter to get it to fire, seems like a lifetime, but seems to be charged back up after each ride which are fairly short, 20 mins or so. The battery is newish & cranks well.
The pilot screws are at 2 & 1/4 out.
I spoke to the guys at the Kwakka shop sounds like a blockage to them so I'll have one last look & if no success they can have the carby's to check & flow test. He also said re jetting is un necessary, it should still run well on standard jets.
Fingers crossed I find a blockage.

[willrcr15]

Well I found something odd, the main jet needles are different, there are 3 with N96C or O & the No4 carb has a needle with N74E ?
The N74 is very slim maybe 1 mm thick at the tip & a couple of mm longer with no brass washer under it either.
The N96C's are much thicker, about 2.5mm at the tip.
Hopefully this is it.
I checked the exploded parts scheme & they list the slim one,N74, but as an obsolete part on Partzilla.
The ones listed as available are N141 or is it N14i ?
I think dad said the GSXR has different needles but on purpose.
I just checked the Haynes & theyre supposed to be 1 & 4 N74E & 2 & 3 N141 so here lay a problem I hope.
I'll go right through & check all the jets as well, someone has been stuffing around.

[NINJAINOZ]

The 2 inside main jets are slightly larger & the 2 inside needles are slightly shorter to help the inner cylinders run richer = cooler

What size main jets are in there?

This is from my factory pro jet kit>

[willrcr15]

Thanks thats a great help,
I'll have a look today in the arvo, I'll go right through & check everything
I'm up for new jets so I might as well go the whole hog & use the suggested upgrades.
I had a good night's sleep last night

[willrcr15]

Well its not just the needles its the main jets as well.
It's got 132 & 138 main jets ??
The N69C needles are off the J models 2001.
But Kawasaki Ncle said the Needles aren't available anymore, I can get the 180 jets but none in stock in Aus, 3 week wait.
What a bloody mess.
Does anybody have jets & needles or just needles & I can order 180 jets & wait ?

Regards Mitchell

[NINJAINOZ]

ALL the details were in the links I sent>
It was much cheaper to order 4x pilot jets (N242-25B) & 4x main any size (99101-393) from the USA>

Fast & professional service from these guys, Probably quicker service than buying in OZ & they know their stuff too
http://www.power-barn.com/servlet/the-I ... Categories

I bought a total of 8 jets from the USA for just under $40 including postage
That would cost around $80 in Australia or if anyone can tell me where they can get genuine keihin jets (Not cheap chinesey ones either) cheaper please give me a link or phone number

According to the link below you should have the following jet needles>
2x http://www.motosport.com/AU/motorcycle/ ... 16009-1778
&
2x http://www.motosport.com/AU/motorcycle/ ... 16009-1779

Them main jets are way too small, Seems like the carby's you have are from the J model (((1991))) not 2001
The J models were restricted & underjetted/lean, They should be fine though if you get a carby kit & up the size of all the jets

[NINJAINOZ]

These would be exactly what you are looking for, Not the best pic (below) but it does show they are the correct length

2x shorter ones on the inside marked N14i KAWASAKI part number 16009-1779

2x longer ones on the outside marked N74E KAWASAKI part number 16009-1778

These retail for $33.84 each here in Aus>
http://mototech.com.au/search-oem-part. ... yes&bike=0
http://mototech.com.au/search-oem-part. ... yes&bike=0

PM & make an offer or the Factory pro jet kit may be a better option for you in the long run>
http://www.mickhone.com.au/cms/id/97/6