I have a Ninja 600 E ZX with a aftermarket pipe and K&Nair filter.The problem is the engine starts and runs fine until I start getting into higher RPM's or jump on the throttle. It starts to back fire and cut out until the RPM's come down. I took it to my local Kawasaki shop and they did the following.

rebuild and rejetted the carbs
replaced the spark plugs
checked the timing
checked the valves
checked the charging system

I finally had to pick it up after they had it for 3 1/2 weeks. It still runs like crap. I have ordered a new fuel pump and a timing rotor, because they siad it looked to be aftermarket.

Anyone have any other ideas? If i cant get it soon Im going to take it to a different shop.

 

welcome to kf

Looks like things have been checked. Although the coils were not checked according to your list. Normally what you listed above is a general cause/fix to your situation. Keep us informed.

 

what RPM is it happenin at?

welcome to KF!

 

So here’s what’s going on now. I have noticed that it is a lot worse now that i have gotten it back from the dealer. It is bogging down if you give it any more then quarter throttle in any gear, and it won’t go any faster the 70-80 mhp and the more gas you give it the worst it gets. Also i only got 80 miles out of a fuel tank, and i was getting 170.

They did change my jets in the carbs, so i am starting to think that it is a carb problem and the dealership just didn’t know what they are doing? They gave me the original jets back with the bike. do youthink that they could have put the wrong jets in? How do you know what jets to use with a aftermarket pipe and air filter.

Does anyone have a good website or diagram on how to adjust and tune the carbs on these bikes.. I have a service manual that is very limited on adjustments

 

yeah.. my 6-E got 160 to the tank all day long with a full muzzy and jets.

you don't really NEED to rejet with a pipe.. you can usually play with the carbs enough to correct the A/F.
could be out of sync, or might be stuck floats.. sounds like fuel starvation..

hm.. keep us posted man.. wish i could help ya more..

 

Did they replace the right jets? I have a mechanic friend who told me a story about someone who changed the wrong jets, with similar sounding results. Thankfully I asked him BEFORE I did my kit

 

yeah, concentrate on your sync and carb stuff. If it "clears up a little on a wfo", check the sync. Does sound like a lack of fuel, fuel filter, float height, or acv diaphram not placed correctly.

 

yuppers.. remember that the jets ARE staggered too.. the #2 and #3 are a different size than #1 and #4.
1/4 are the same number, and 2/3 are the same number, but they're usually separated by 10.. like 170 innies (2/3) and 180 outties (1/4)

also with that rotor.. even if it's aftermarket, it should sit tightly on a roll pin pressed into the crank end. theres a tiny pin there that WILL NOT permit the rotor to seat flush if the pins not sitting in a groove milled into the rotor.

if it's out, this will make it backfire like a m.f.er, and it won't really wanna start, depending on how bad it is.

so what if it's aftermarket! did it run with the stock jets and this component in question in place? if so, they're full of chit. di dthey correct float height? sync the rack? test and tune it and correct A/F under load?

this is what scares me about the industry. shadetree cats that don't belong in a shop with a wrench..lol

 

I messed with it all day today. I put the stock jets back in it, and it runs a lot better. still cutting out tho. I did notice that the pilot screws have been messed with. Because there where no caps on them. They where all that 2 1/2 turns out. I tryed turning them to all kinds of different setting and then riding it, but i had no luck..

I am calling one of st.louis biggest kaw dealers tomorrow to see what their service schedule is.

 

hmm, ok, what is wrong with playing with the a/f and listen to the KF crew? Good luck just the same.