95 ZX6R Problems PLEH! PLEH!

I've been having some strange issues with my 95 Ninja the past 2 days. Last night while on the beltway, for about 5 minutes, my bike would not go past 60mph even on a level straightaway with WOT. It had been up to 90+ just minutes before. Not the best place to have your bike suddenly loose speed. Five mins later it seemed fine, but it would not MOVE! There was plenty of fuel.

When performing an emergency stop from 50mph or so, keeping the clutch in while downshifting so it wouldn't stall, before I hit 10, my engine shut off. If I needed to immediately zip out of the way, I would have been SOL. That was weird.

Off the line I doubt I could beat a yugo, as it lugs severly in the low gears, and when at a stop, idle chugs as if it is starving for gas, but there is a FULL TANK! Here's what I've done...

Removed tank and looked at air filter. Only very very slightly dirty, so I cleaned it and removed all the bugs out of the airbox. Yes I did cover the four valve holes with a rag to prevent anything falling in there. Adjusted the idle speed with the little knob so it idles higher now, say around 1200 rpm but still is sluggish off the line. One of the fuel lines had a kink in it, but it was the reserve line so I don't think that could cause a gas clog up since I run off the main line. That was rectified by shortening the fuel line.

It was suggested that I clean the carbs. Since I've got the tank off and air filter off, might as well attempt it. My questions are these. I'm a wrench head novice (I"m a wiz building guitars and computers, not small engines!) and I can see the four valve holes, and what I think are the ends of the jets. From what I see, they look very clean in there. Are the carbs just the fly wheel things that cover the jets? What else do I have to remove to get to them and is this something that I should take it to a shop to have them clean them, or is this something that a novice can attempt that is not that difficult to put back together!

Anyone have any suggestions as to what might have caused the sudden speed loss or carb cleaning tips? Thanks a bunch.

strat

Maybe try switching fuel petcock to reserve position and see if that changes anything.

Fuel would be the most likely cause, an inline filter or a screen in the petcock/tank. I dunno your bike specifics, but many have a strainer screen on the petcock inside the tank. Could get plugged after 9 years.

Myself I would take the fuel line loose and make sure it's flowing gas visually.

After that would be ignition or ignition advance not working I would think. If the gas flow is good, probably time to take it to a shop unless you can diagnose igintion, or worse if the engine is mechanically hosed.

That sounds like a fuel problem, Dyna Sport is on the right track about the petcock, but it could be that one or more carbs got some trash inside them and there's not enough fuel.

Just looking at the inside of the carbs won't tell you much, even if they look clean the holes on the jets are so small it takes almost nothing to clog them.

Are you located in Houston?? Maybe I can give you a hand, just another excuse to go riding somewhere.

Is it still running on all four cylinders? Try throwing water on the header pipes and see if one or more of them is not as hot as the others. The header should sizzle and quickly evaporate any water put on it. Next pull your plugs and read 'em. 90% of your diagnoses can be made by reading your plugs. Use this chart Big image of 29 spark plugs. What ever you do, don't dive in to your carbs without knowing exactly what your in for. Check this link for a step by step teardown of some constant velocity carbs which are probably like the ones on your ninja, although I'm not positive about that.

Look in your gas tank and see if you see ANY rust. Even the tiny, little, fine, powdery stuff. If its red tintedin there, then you have rust. If this is the case then theres plenty of work ahead but you can do it.

Does this bike have a vacuum operated petcock? If it does then check or replace the vacuum line. If that doesn't work then look at the petcock.


Definately read the plugs before you do anything else. Read more about bike repair here. It is a wealth of information about bike repair.

Good luck with this!

Thanks for the ideas. I did get a set of plugs as that was what i was thinking to check, but more on that later.

Well, I got the air cleaner box off and the repair manual said "take off the four retaining screws for the carbs". Well I dunno how in the **** you could accomplish that unless you are plastic man, so I just sprayed some carb cleaner in the openings I could see (not a lot mind you) as after an hour of trying to get the carb assembly off, I resigned myself that I must not be a wrench head when it comes to internal combustion engines!

I did however spy a small tear in one of the rear lines from the back of the tank, (not the main ones) so I replaced that line, then it wouldn't start! Apparently the way I had it sitting the line went a little bit too upwards and must have caught an air bubble in it, so reorient the line and then it fired and started. Had some carbon deposits get blown out of the exhaust so there must be some gunk in there, so the carbs probably could stand to be cleaned, but it's either a shop call on that or a case of beer for a friend of mine if he's willing to sacrifice an entire afternoon helping a wrench inept like me!

It was also suggested that my "flat spot" the other night might have been caused by a deposit clogging something preventing fuel flow, and then it either got sucked back or blown out. Good to know.

In doing some research on this kawasaki forum, it's not all that uncommon for these bikes to shutoff from hard stopping, so I'm not ultra concerned about that since it does not appear to be an anomoly only to my bike. It's happened to my friend numerous times, on various sportbikes.

But now I'm really good at taking the tank off and getting to the air filter which I think I will go and replace. BUT, I figured that if I was going to get that carb assembly off, might as well change the plugs so I have a brand new set of NGK plugs, but that looks to be even more involved and inverted hand positioning than removing the carbs, another call for the shop I guess. Wow, saved 14 whopping bucks by having them beforehand!

Guru diagnosis is to drive the crap out of it at high revs every now and then to get some of the crap blown out. I admit, even though I've gone 120mph on this bike, don't think I've ever crossed 10K on the tach gauge while having it in motion. Sure at a stop on the stand I'll rev it like it was done today, guess I need to do that more often while in motion! I cannot wait until I can get a NEW fuel injected bike, think I'd have less headaches with one of those, and plus, it's computer controlled and ****, I at least understand those silicone based breasts, I mean BEASTS!
Thanks for the ideas/input

strat

Hmmm... I happen to know someone with a nice fuel injected bike for sale...

Hi Strat,

This sounds like one of three things: a coil, CDI box, or vacuum slide (CV carbs).

Coils tend not to be intermittent, they usually just quit. I'd check your coils anyway. If you have one bad coil (with multiple coils), it will still run, just like crap. Sometimes it will quit only when hot. Also check your coil/ plug wires.

If it is intermittent (or not), a CDI is a likely culprit. I 'm not familiar with Ninjas, so I don't know if you have 1,2,or 4 CDI's. With that kind of power loss, and if that's your problem, it sounds like you have 2 (usually only singles have 1, and it will usually just quit intermittently, and I don't think 4 is likely). You can remove the CDI's and take them to a kawasaki dealer to be checked, or try rotating them (switching positions). Find out which unit operates the tach, and if the tach stops working during the rotation, you've found your culprit. If you know someone with a bike like yours, ask to borrow one of theirs, switch it with each of yours, then when it suddenly runs properly.... also you may try unplugging each, the one that doesn't affect it wins.
check this out:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=35594&item=7903561479
New, they'll likely run for $200-300 each. I've had CDI's go bad on 2 different bikes, and on on my RX-7. It happens.

Do you have CV carbs? CV carbs use a vacuum operated slide, if the vacuum diaphram (rubber thing under the cap at the top of the carb) has a tear, it will have little power, but will seam to idle normally. This is because it only affects the main jet, which becomes inoperable. I've also had this happen on two bikes. This problem, however, shouldn't be intermittent.

Anyway, if it just suddenly loses power and doesn't spit, sputter or miss, it is likely electrical in nature. Have you noticed a pattern, or any other observations?

If you'd like to know more, let me know. Do you have a shop manual?