1988 Ninja problems

[njsrikar]

hi,

I recently bought a 1988 Ninja zx750r. It ran fine from the day I bought till the past week . About 10 days ago, on a warm morning, the bike died suddenly when I was waiting at a traffic signal. That day, I rode it in heavy traffic, could not even shift to 2nd gear, so I thought it might be a hot engine. I started it again after 5hrs and it fired up right away.

I thought it might be a battery issue and charged the battery overnight using a trickle charger.(btw...its a brand new battery I bought after buying the bike).

After a day, this happened again in the middle of the road, this time, the engine was not that hot and it was a comparatively cooler day. Again, I left it for a few hours, and it fired up immediately at the first try.

So last weekend, I looked up craigslist for ppl who would work on these old bikes. I told him the problem, he said it might be a coolant issue or something, so he put in a new coolant and also I asked him to clean the carbs. But after working on the bike, he told me it might be a stator problem and the price he quoted for replacing the stator was very high for me. I towed the bike back to my house yesterday, charged the battery once again over night and today, I rode the bike. I was afraid it would halt somewhere again, so I did not go far away from my house. I live in the boston city, so tested the bike riding along by-lanes and a few traffic signals. It ran fine for 7 miles and then suddenly died when I stopped at a STOP sign. Same problem again, it doesnt start, tried 2 3 times in vain. I dint want to kill the battery, so did no more trials and pushed the bike home.

Before all this started happening, I rode the bike for about 500 miles without any problem. I also went on a ride along with fellow NESR member, Sean aka slammp to Gloucester, faced no problem at all.

What do you guys think is the problem ? Is it the stator ? if so, can anyone help me get it repaired/replaced, for a lil lower price ?

Please help/suggest.

Tomorrow, I am thinking of removing the engine cowl and see if that helps cooling the engine.

Thank you.
nJ

[Jim]

send a PM to TLRman, and see what his thoughts are.

as far as the shifting issue on an older ninja, talk to Omahasteaks. he had a similar issue on his ninja, and it recently got fixed.

[njsrikar]

update: I tried starting the bike just now and it started without any problem. All the indicators and lights are bright, meaning the battery is fine too.

@DBKromz........what shifting issue are you talking about ? I am sorry, but I could not get that.

[Jim]

click me.


note: I call him Omahasteaks, and that's not his actual screen name

[njsrikar]

click me.
note: I call him Omahasteaks, and that's not his actual screen name

Thanks for the immediate reply. I PM'ed TLRMan just now. Awaiting his reply.

And yeah, I dont have the shifter problem omahastylin had.

[Jim]

degsy could probably fix the bike too

[Ericthejet]

I have been in the same situation with my 1984 Ninja 900.

This really sounds like a fuel tap issue.
As they age they get sticky internals and will without warning stop the flow of fuel
as you describe causing "sudden death".

When I first got my Ninja (8 years ago) I would be out on a ride and without warning it would just stop. It did not occur to me at the time to switch the fuel tap over to "prime".

If you want to test the fuel tap set it to prime as you start out on your next ride. I'm confident you'll not have this condition happen again.

If you wish to rebuild the fuel tap PM me as I have a great diagram of the internals and Kawasaki.com and Z1 Enterprizes both still stock the kit. It takes about 30 minutes to repair it.

Since I have learned of this weakness the bike has not repeated this sometimes frustrating little habit.

[njsrikar]

Yeah, I read another thread with the fuel tap issue and I also saw the website of the fuel tap diagram. but am a complete newbie to all this stuff.

Can you tell me where is the fuel tap located and to which direction do I turn it to get it to the PRI position ?

Will try it today.
Hope its fuel tap and not the stator.

[richw]

Also fuel vent in tank

Try opening the gas cap close it and see if she fires

[Ericthejet]

Fuel tap is located on the left side of the tank.
When facing the tap,
the lever "end" is the pointer.
Pointing to the rear of the bike is "run".(3 o'clock)
Pointing down to the ground is "Prime".(6 o'clock)
Pointing forward is "reserve".(9 o'clock)

Hope this helps.

[njsrikar]

Oh...is it the same location for all the bikes ? I am pretty familiar with fuel taps. Our Indian bikes have them, with 3 positions ON, RESERVE and OFF. I thought these big bikes do not have them. And yeah, I did not find such a fuel tap anywhere below the tank of this ninja 750. is it hidden behind anything ?

well....I was thinking...if it was a fuel tap problem and that the engine is starving of fuel, why does my bike start(with a lil bit of choke) after leaving it off for 3 or 4 hrs ? This thought made me think that it might be a engine over heating issue.

[richw]

VENT VENT VENT

no air in
No gas out

eventually air leaks in over time...

seroiusly ride around your neighborhood until she dies
Take off gas cap listen for suck
replace gas cap and start

[njsrikar]

by gas cap do you mean the fuel tank's cap ? i`ll try it out today evening after returning home.

Thank you guys for the help. WIll try both the solutions and update you guys by tonite.

[Ericthejet]

If the bike sits for a while and starts back up it may be because the diaphram inside the tap has relaxed and returned to a normal poisition to allow fuel to flow and not stuck closed.

Unless this bike is fuel injected it should have a fuel tap.
Tucked in behind the left side fairings?

[njsrikar]

If the bike sits for a while and starts back up it may be because the diaphram inside the tap has relaxed and returned to a normal poisition to allow fuel to flow and not stuck closed.
Unless this bike is fuel injected it should have a fuel tap.
Tucked in behind the left side fairings?

Oh...if thats the case, then it might be the fuel tap issue(and i hope so!). I bought this fella on 6th April. The previous owner did not use it for 6months this winter and after that he took it out of his garage right in front of me when i went to have a look at it. So there is a possibility that the fuel tap might hv got rusted.


^^this is the best pic i hv of the bike from the left side. Do you have any idea where the fuel tap might be located ? I will be going home in another hour or so and will look for it.

And...do you know what are the indications if the stator goes bad ? I mean, how does the bike behave ?

[richw]

Yes gas cap as in where gas is put in the bike


Fuel tap is automatic uses manifold vacuum to open
Injected bikes have pum,p usually in the tank

You would never go "miles" if the tap was shut entirely

Tap might have a prime setting that bypasses the diaphram

[butcher bergs]

And...do you know what are the indications if the stator goes bad ? I mean, how does the bike behave ?

It's not the stator so don't worry about that right now.


...and BTW, that was my very first street bike, 'cept mine was a 1990.


EDIT: If I remember correctly, the petcock is directly underneath the tank. The carbs are vacuum actuated so there isn't a true requirement for an accessible petcock on this particular machine.

[njsrikar]

well....i tried looking for the fuel tap/petcock for over an hour now and did not find any . I looked all around the carbs, above the engine, everywhere.

But I found something similar, it doesnt have a lever to turn it though. It is a golden screw sorta thing with a flat head. check out the pic....taken from under it.

I saw pipes originating out of this small enclosure and it is right under the tank.(and yea, thats the image i got with my crappy cell phone.)

What do you guys think now ?
I am going to ride this bike now in the neighborhood and try richw's suggestion when it dies.

[butcher bergs]

That's it.

It's vacuum actuated and with that, you don't have a valve to manually close.

[njsrikar]

oho....wat do i do now ???

I am just back from a small ride. This time the bike died in 3 miles. Tried starting it again, when I pressed the starter button, there was a motor sound kat-kat-kat ....and I immediately turned it off. Then tried richw's suggestion, opened the gas cap, left it open for a minute and closed it....no good...the bike still doesnt start. Had to push it home.

[butcher bergs]

Inside of the fuel tank rusty by any chance?

Thinking you might be picking up some contaminates from inside the fuel tank which is blocking the fuel delivery.

...and when you check inside the tank, DON'T use a lighter for light.

[njsrikar]

Inside of the fuel tank rusty by any chance?
Thinking you might be picking up some contaminates from inside the fuel tank which is blocking the fuel delivery.

yeah...u guessed it right. the tank is rusty. so...does that mean i need to change the tank now ???

...and when you check inside the tank, DON'T use a lighter for light.

[Sheppo]

yeah...u guessed it right. the tank is rusty. so...does that mean i need to change the tank now ???

No, but you'll need to take it off and clean the screen on the fuel tap. What is happening is the rust and dirt particles are getting 'sucked' onto the screen, stopping the fuel flow. WHEN it sits for a period of time the dirt slowly falls off the screen until you start it up again and the draw on the fuel sucks the dirt up again. while the tank is off. clean it out

[butcher bergs]

yeah...u guessed it right. the tank is rusty. so...does that mean i need to change the tank now ???

What Sheppo said.

Also, might wanna try to get a pic of the inside of the tank for our viewing pleasure.

Another thing you may want to consider is the fact that you might be performing the process of cleaning the filter a few more times later down the road (no pun intended).

Possibly think about flushing the tank to draw out any additonal contaminates and using that fuel in your lawn mower.

[richw]

KREEM fuel tank liner stuff.. I have used it 2 times was sucessful both times with little difficulty

Rust can clog all the passages in the fuel system

Ethanol; in the gas makes this much worse.. more water faster rusting

Sorry it wasn't the vent