Kawasaki Sportsbike Riders Club - Australia - Online Forum

Hey people!

I have a q 4 u...

My ZXR250 has been playing with my mind. Just recently i have been unable to start the darn thing. Here's some history:

1) I have never been able to use the choke cos the fella i bought it from said it doesnt work (hmmm...)

2) It had spluttering problems when climbing hills of about 20 degress or greater incline such that it was surging.

3) No, the battery is not flat, and yes the starter is engaging correctly.

4) I know there is spark because i just replaced the plugs and leads, and when i give it throttle when cranking it over, it back-fires like "BOOOM!!"

5) Drained the fuel from carb reserviors and its clean.

6) Have had starting trouble for about 5 months now, it finally wont start, not even a cough or splutter!!!

7) The clutch slips a little in second...

WHAT'S THE DEAL??? PLEASE HELP ME, I AM OUT OF IDEAS!!!

if you havnt already done so change the sparkplugs and do oil change oilfilter and airfilter and clean and adjust the chain. Very Happy

If it still does it strip and clean the carbies and take it somewhere for a carbie balance but do do the basic service work first.

ohh and make sure the choke works properly too not because you need it but just so it isnt stuck on.

What fuel do you use??? pulp of some description or whatever you can find cheap on the day.

vortex or bp ultimate contain stuff to keep fuel injection systems clean as well as all the other stuff they put in there and charge a bit more for but the stuff from the small independants could be mixed with anything at times so long as cars still run on it.

The 4 cylinder 250s have really fine jets and airways that really easily gum up hence the strip and clean is important for the carbies, injector cleaner doesnt get the gum out once its buit up.

you could also look at the earths under the coils and also check the spark plug boots for holes i have seen a plug fire right through the boot into the side of the block before.

mate id look at what fuel ur running, sounds like fuel starvation, (the hill climb bit suggests this as opposed to air prob)...take the tank off..make sure none of the fuel lines are pinched, as Barra says, make sure the choke isnt in the ON position...
if uve cleaned the carbs etc, have u drained the tank, checket it for rust etc, and checked the hoses are clear...thats where id start...

your right neka i mised the fuel filters and strainers if there is one inside the tank it could be causing a problem.

I had a cbr250 they where a great thing to play with and being a older bike you can have fun pulling it too bits in the kitchen and might even learn a thing or two while you are doing it.

sometimes they just need a good sorting out and they are fine for the life of the thing after that.

Thanks for the replies.

Theres no rust in the fuel.

when i removed the old plugs, one of them was covered in fuel...

is it ok to remove the carbs without resealing them with some kind of gasket or goop, this is a concern to me considering the trouble i went to looking for new leads. I had to make my own in the end.


I run BP ultimate 98 ONLY. I will not run anything else. i have a feeling it pretty much gonan be the carbs, unfortunately.

stuck needle and seat or gunked up on that cylinder or that plug isnt fireing for some reason.

yeh you can replace them without goop so long as you can get them off in one peice.

its probably best to pull them all apart one at a time and spray them out with carby cleaner anyway and watch out you dont spray any in your eye.

if you can blow them out with a compressor as well its even better and spray a bit of cleaner in the float bowl and let the jets soak in it for a bit.

might even find a how to on the net if you google a bit.

its best to warm up the engine before you pull the carby block off because it makes the boots realease a bit easier.

If its leaking down fuel from the carbys overnight it can cause hydrolock which is where the cylinder fills with fuel overnight and you go to push start it and bend a conrod....this is bad.

if it has a fuel tap turn it off when you stop that should slow it down a bit till you fix it.

I would take it to a dyno tuner and have a look at the chart, but you may need to fix the carbs first to get it there, but once running on the dyno they should be able to pinpoint whats wrong and why its doing it.

Wonder Wheels wrote:I run BP ultimate 98 ONLY. I will not run anything else.

thats probably the problem right there. old carb'd bikes are absolute whores to start with 98 octane fuel, and if you start it up once and then just shut it off without taking it for a ride, you can garuntee your plugs would be completely fouled. these bikes were all designed for 91 octane unleaded, anything denser and it will run too rich.

try taking the plugs out and if they look black or dirty, spray them with contact cleaner and give them a very light rub with some sand paper to clean then up...

i would put some normal unleaded in the tank, to get any real benefit out of higher octane fuel you would need to tune it to suit, but it can still be very hard to start in the morning.. even my ZX9R doesnt like starting on cold mornings with 98 octane fuel in the tank... ive tuned it to suit 95 octane and its fine tho, and stock minimum is 91 octane


also, one really quick easy thing, have you tried push starting it? even when the battery isnt "flat" as such, it can help a bike with fouled plugs to start ... you get a huge voltage drop when your holding the starter button down, even if your jumping it from a car... and the coils are only getting about 10V rather than the ~13-14V they get while the engine is running (or ~12.5 while its off) and AFAIK bikes dont have ballast resistors (inductors?) like most cars do to run them on 10v the whole time


if you try all that and still no good, then i would think about pulling the carbs off... give them a quick clean and check that the floats are set at the correct heights, and check needles and emulsion tubes for wear... make sure the slides move freely with a nice suction noise and spring back perfectly. have a look at the idle jet, make sure its not blocked or anything... turn the idle mixture screws all the way one way then all the way the other way and then set em back to what they were originally incase theres some crap in there..

if the choke is hooked up, you will probably find it works fine once you have normal unleaded in the tank.

how full is ur tank... is the reserve switch working
i would get the choke fixed as well as mine wont start at all in this sort of weather with out the choke. they are not the best chokes but are better than nothing.

I'd be looking a t the choke too. My zxr250 wouldn't start without choke in winter.

ne news mate?? problem fixed??

From what he says it has fuel, and spark. So it can only be missing one thing.........Compression!!!! Do a comp check! 250 fours are notoriously hard to start if there is any loss of comp or leakage thru the valves. It's common on all the little 250 fours!

HHHHHHHAAAAAAAAAAAHHHHHHHHHHHAAAAAAAAAAA!!!!!!!!!!!!!!

The bike is now running guys, took it to Show and Go and they had it running the same day.

And the problem was......... DIRTY CARBS!!!!!!!!!!!!!!!!

That's right, even though i took them apart and they looked pristine inside, they were blocked up somehow. They just cleaned them and now she starts no worries.

So thatnks for all your help guys!

perhaps invest in a new fuel filter

Wonder Wheels wrote:HHHHHHHAAAAAAAAAAAHHHHHHHHHHHAAAAAAAAAAA!!!!!!!!!!!!!!

The bike is now running guys, took it to Show and Go and they had it running the same day.

And the problem was......... DIRTY CARBS!!!!!!!!!!!!!!!!

That's right, even though i took them apart and they looked pristine inside, they were blocked up somehow. They just cleaned them and now she starts no worries.

So thatnks for all your help guys!

im glad u find it funny...

ive heard good things abt show and go...glad its sorted mate