No prime on the petcock - just Off, On, & Reserve like you stated.

How well was it running when it did? I'd perform a compression test if you have any doubts about the motor.

What did the plugs look like when you pulled them last? Definate indications of being flooded?

Did you completely clean the carbs? What condition are the float needles in? They might be worn or have some dirt on them causing the engine to continually flood.

 

How much fuel is in the tank? Generally speaking the pump is not required for about top half of the tank (gravity feed is enough when tank is full).

Check for fuel flow at the line going to the carbs, it should be fairly strong. If not, check filter in tank (attached to fuel petcock) to see if it is obstructed.

What is coil primary voltage when bike 'dies'?

Are plugs wet when bike 'dies'?

 

when i eventually got it running, it ran pretty good. the only thing i can add to that was when it was standing for a year before i bought it, when i did an oil change their was petrol in with the oil. but i havent seen it happen again.

if anything because of the smell of petrol it could be overfueling? either way it chokes up like a typical carb engine thats either under or overfueled. then wont start again.

usually there's over 1/2 a tank in the beast.
when you say the pump is not required when its full, can you turn it off?

I've had new floats put in, carbs been cleaned twice (once when originally checking out the floats and jets, and again when new floats and jets went in)
and i've had the coils replaced. not sure what voltage they are at when it stops, but did replace em just in case.

last time i pulled the plugs, i put them in new fresh and dry. it started. 20mins later it stopped running, pulled em out (about 30-40mins total time) and they were ringing wet.

the filters look pretty clean, but i'll double check that one at the bottom of the tank. i wouldn't have thought i'd have missed one unless its one i didn't know was there. but judging by the petrol smell i assume its running through plenty well enough

 

No worries with the tank filter if the plugs are coming out wet.

How is the oil level? If it's overful, it's definately contaminated with fuel. Change it out and start over again.

The fuel pump exhists to drain the bottom half of the tank as it may be slightly lower than the carbs. This is a 'typical' setup, may not be accurate for your bike, but is now also not relevant.

When the bike dies, is it sudden or over time?

As suggested by WeBeToyz a compression test is in order. Charge battery fully. Remove all spark plugs, install tester, set Kill switch to off, with Throttle WIDE open crank starter, count five 'bumps' on tester guage and stop. Take reading. Repeat with remaining cylinders.

Readings should be 5-10 lbs within each other, look for readings higher than 120psi to indicate a long term viable engine.

Once successfully completed, reinstall plugs, move kill switch to run.

Test Coil voltage. In an ideal world they are the same reading as at battery, some losses are acceptable, no more than 1.5volts (if battery reads 12V, coil reads 10.4, no good - 10.6 or more OK).

Compression testing is a must, and often skipped test as we are 'teased' by these bikes (runs short term).

Honestly, I think you have an electrical gremlin.

Rob

 

just to add....ive been told its an L2 model.
one other thing. when i had all the floats and needles done. the guy who did it found that all the carbs were running at different heights. and he reset to standard when the floats and needles were done (apparently).
now this has also got me thinking.....if the guy didnt know what he was doing or if the carb settings are different between L2 and J models he could have messed em up causing the overfueling problem?

i'll get another compression test done. so far 3 people have said its fine. one racing company said after 1hr that the engines on its way out (looked at it as a favour). but did not say exactly why it was on its way out and as far as im aware didnt do a compression test.
during the brief times it runs there is nothing to show that the engine is going. in fact its an awesome ride and makes me think the opposite.

but i agree i think it could be an electrical problem leading to overfueling.
when the bike dies, its like its ran out of fuel. or choked up with too much fuel.
its getting it started after which is the thing.

 

been to see the bike today......again
its overfuelling. it started. choke on 1/2way to start it, 2 mins in choke off.
then ran fine for like 5mins, then revs started to die off on tickover, then died.
could get it started again but if you used the choke it would die off. and you had to keep it revved. then you would get pops and bangs of unburned fuel.

once engine was warm/hot it wouldnt start again. when you turned it off,

smelt of petrol. left it for 20mins, found a few drips of fuel on the floor from where unburned fuel got into the bottom of the exhaust. started fine again, then problem appears again. so to me that points to overfueling. i assume its not been tuned correctly by the last guy.
checked the oil level. looked ok. BUT the oil did smell like it had petrol in.

so then experts.....what 1st.
try another set of carbs?
oil change then dyno?
compression test then the above minus the carbs?

no problems with it cranking, and it was sparking ok. when its revving it sounds fine too. no untoward noises from the engine. just dies off when it gets overfueled.

 

Try pulling the air filter out of it: What's it look like? Is it a factory paper element type or reusable filter?

Is is soaked in fuel?

Is there fuel in the airbox?

Can you post a pic?

If no to above, see if it will run without the air filter. This is obviously for testing, extended operation without an air filter will greatly reduce engine life.

 

just to add....ive been told its an L2 model.

Hmmm...probably should get the year/model number straightened out. If it is an L2 then it is not a '96:

1993 - L1
1994 - L2
1995 - L3
1996 - P1
1997 - P1

You can verify this with the VIN. You might be able to look it up online at the Kawi site - don't know. Clymer manuals have the VIN breakdown in them for these years. If you can't figure it out, PM me & I research it for you. Or post a couple of pics & we should be able to tell from that.

It would make a difference in the settings for your bike. '93-'95 is pretty much the same, with '96 on being different.

just to add...if the guy didnt know what he was doing or if the carb settings are different between L2 and J models he could have messed em up causing the overfueling problem?

Most likely so.

i'll get another compression test done. so far 3 people have said its fine. one racing company said after 1hr that the engines on its way out (looked at it as a favour). but did not say exactly why it was on its way out and as far as im aware didnt do a compression test.

None of these people provided you with the numbers between the cylinders? If so post them - if not, then a compression test is the first order of business. I would get a wet & dry test done.

 

WeBeToyz
im based over in the UK. and L2's were available until 1996. its a UK road registered 1996 bike, but the bike was manufactered in 1995.
i double checked the vin, and it says its an L2 with a JE engine code.

no i didnt get the numbers on the tests. which leads me to think that there is a possibility that a compression test hasnt been done at all. and ive been charged for it.

LoudFastUgly
i wasnt in the mood for taking the airbox out :mrgreen: but i wouldnt be surprised if the airbox was fueled up judging by the smell. thats another thing for me to try out. of course i cant run it longterm without a filter. but if it runs that could potentially point me to some breather problems also.

 

I know you've looked at them twice but all the symptoms point to fuel just running freely through the float valves. As they are new it's unlikely to be poorly seating float valves unless they are completely the wrong ones fitted. So my guess would be severely incorrect float heights allowing the engine to flood. The only other way so much petrol can get through from the tank that it runs into the oil and exhaust is if your petrol pump is putting out about 10 times the pressure it should or you are holding the start button on and the throttle open for ages until the battery goes flat, even then CV carbs require vacuum for the slides to open right up.

There are 2 simple tests which involve some dismantling;
To check if it's the float valves. With full tank of fuel. Undo all the carb clamps, bypass the fuel pump with a hose directly from the tap to the carb, turn the petrol tap on, wait 5 minutes or so then pull the carbs out of the engine rubbers and check if petrol is running down the bore of the carburettors. If it is turn off the fuel tap, drain the carbs then turn the carbs over and remove the float bowls. You can check the float heights are correct with a ruler but a simple visual test is if they sit down into the carb body they are set too high (cause flooding), if they are standing level/just proud they are roughly right. I doubt they are standing way up as that would lead to opposite symptoms of fuel starvation.

If there was no petrol in the first test then put it all back together as standard but without fully tightening the carb clamps, start the bike, run for 5-10 minutes then pull the carbs again to repeat the check after turning it off. If there is now petrol running down the carb bores it's the fuel pump over-pressuring.

If you don't want to take anything apart yourself another way to check for flooding is to start the bike, turn the fuel tap back off for a minute, turn it back on for about 15 seconds and keep repeating this. Hopefully the engine will just keep going and not choke up and die. Depending on how badly the engine is flooding you might have to adjust the length of either the on or off interval but if this procedure means that the bike can run indefinitely and not choke out then flooding is the cause of your problem.

this link might help

Factory Pro Float Height Tool

Regards
Bren
(in UK with ZXR750L3 @900cc)

 

if im honest, i had a look at the carbs, cleaned it all out, put it back together again. as i didnt know the correct settings.
i let someone else do the work on replacing the needles and the floats. i dont know if this guy actually managed to do it correctly. judging by the smell of petrol i dont think so.

bren, some good things to try out there. i will do that later this week and report back.
i'll also go get a compression tester and do that myself. then i can see that side of things with my own eyes.

 

I would check it's not flooding before carrying out compression testing. You don't want it to diesel on a cylinder full of unburnable fuel and bend a rod. If the flooding is as bad as you've said that petrol gets in the oil it is doing that by seeping past your rings which means that your cylinder bores are washed clean of all oil and aren't protected so you might cause some heavy wear or in worse case snag a ring and gouge a bore. Also your engine oil will be at best like flushing oil and fuel vapours in the bottom half won't do non-submerged components any good and will increase the crank-case pressure.

 

I agree with Bren's approach on this. The only thing I would add is that while you are in those carbs, verify the correct jets are installed and not something over sized.

 

what size are supposed to be the std size jets?
i have the old ones here too so i can compare with whats in there now.

 

Kawasaki.com shows a 35 pilot and 2 options on the main, 170 or 180. Not sure which main would have come in yours.

 

Bren, just thought i'd post up on this thread (to help any future searchers)
that your tip to test out by turning the fuel tap on and off etc worked a treat in helping me diagnose it was 1000000% a fueling issue. more specifically an overfueling issue. i did it yesterday.

i managed to bring it up to temp till the fan kicked in, with a better tickover and generally making it sound a whole load better just by doing that. was running for about 30mins till i got bored of counting the minutes...tap on...tap off....etc. i then let it see how long it would go on for when i turned off the fueltap. a further 10mins till it stalled.

anyways, not attempted to fix it yet. but to save problems i have sourced a new fuel pump & fuel pump relay which i will fit 1st along with checking the connections. then i'll whip those carbs off and set em up.

the only other thing i will check on is that there is not a fault with the fuel tap. but a couple of months ago when i took the tank off that stopped and started fuel so i think thats fine.

thanks for your help guys!

 

I'd bet my last tenner after that test that your floats are sitting way too high Alex (look like they are sitting down in the carb bodies when you turn them upside down to adjust them)-hope you manage to set them correctly and get a refund off the muppet that charged you for doing them wrong.

 

well....i thought id bring this thread to an end.
couldnt get the float chambers apart. (something dodgy there) so ended up getting a 2nd hand set of carbs. looked like they had never been apart. and never been tampered with (had std jets, std synchronised settings, std idle settings, std fuel settings), so after a bit of looking at em, cleaning em up. checking everything over....put em on and all seems well.

now doesnt stink of petrol, runs with the fuel tap on all the way, choke operates as it should. and generally....apart from a touch rough on idle till it warms up (nothing out of the ordinary for an old vehicle to me) it works well. so thanks for the advice! if it plays up again i'll probably post on here again.