zx2r cold starting problem!

[zx2r1994]

hi guys, ive had my bike for 6 months now and its been soo much fun riding everywhere. However, over the last week, ive been having problems starting the bike. The problem is, i am having difficulty starting the bike when its cold (sitting in the garage over night). Keep in mind that once i get the bike started, it runs perfect.

I will try and crank it over 10-15 times, for about 3-5 seconds each time time, and it wont start, although i can hear the starter motor kicking over. If i leave the bike and wait 5-10mins, and try and start it again, usually it can start straight away. (although sometimes after another 10 attempts i will need to leave the bike again, and wait another 10 or so minutes, but it will eventually start). Once the bike starts up, and its warmed up, i can start the bike straight away with no problem. If i leave the bike for 10minutes, or 4hours, it will start straight away with no problems. Only when i leave it for an extended period (once the engine is completely cold) it will have trouble starting again.

At first, i thought it was a bad battery, so i changed it over to a new yuasa battery, and leave it on a trickle charger. However i still get the problem. Next, i thought it might have been bad/fouled spark plugs, so i replaced them, however i still get the same result.

Im completely lost as to what couldd be the problem? Would engine oil be the problem ? - when the engine is cold, the oil is thick, making it hard for the engine to start. however from turning over the starter motor multiple times(10-15times), the engine oil gets pumped around and makes it thinner, making it easier to start??

Another thing is, I need to get my cam chain / tensioner replaced (i can hear the noise, and i will get it fixed ASAP!), could my cam chain/tensioner affect the timing of my engine?..im not sure why it would have trouble when cold, but not when warm? If the cam chain was the problem, im assuming i would have the problem irrelavent of cold or warm?

If any of the kawi gurus out there have any advice / idea of what the problem is, it would be greatly appreciated.

Cheers

[dilligaf]

carbies? I gather it has a choke. does it make a difference?

[dave#3]

What is your starting routine? Do you use choke? Does half choke / no choke alter the results? What about throttle position? WOT, closed throttle, a few blips then start? How long since the valve clearances were checked? Were they done professionally (or by an experienced home mechanic)?

[mike-s]

Regarding the starting technique, it varies per bike. one of my old bikes refused to start if you did anything other than 1/2 to 1/3 choke and 0 throttle. My RF doesn't really need choke unless it is the middle of winter, and can start with anything up to 1/4 throttle. The GSX needs 1/4 choke and just a touch of throttle and dies if more choke or throttle is used and can pop and fart for a minute or two and until it warms up. This is with having clean carbs and a redone head/valves.

Also have you checked the compression on it? a compression tester can be gotten for under $50 from supercheap, etc.

[zx2r1994]

well before i had the starting problem, it usually takes 1/2 choke and no throttle to start her up. however, since ive had the problem, ive tried a lot of variation, from no choke to full choke, with no trottle to full throttle.

Im not sure when the valve clearances were done...havent done it since ive had the bike (6months). could this be the problem? would it affect the bike when starting cold, but not when the bike is warmed up? (how much would it be to get it done btw?)

so u guys dont think the cam chain/tensioner would have anything to do with this?

Thanks for the help guys, really appreciate it.

[mike-s]

It's worth noting that valve clearances tighten up when the engine is hot due to metal expanding. So accordingly the clearances would be looser when cold, so if anything, aside from fuel vapourisation being more difficult when cold, an engine should be easier to start.

[Supafrog]

First thoughts:

Sounds like it is flooding - hence starting it later after letting it sit seems to work.

Is it electrical fuel pump? I do apologise.. as what year is the zx2?


Whats' the strength of spark? ie: have you inspected the spark plugs ???

Timing will definitely affect starting..... but first check the strength of spark.. ie: could be coil related?

Does the choke actually work? (i say this becauese i had a bike that the lever worked, but didnt actually actuate the choke on the carbs...)

[zx2r1994]

if i am not mistaken...it does not have a fuel pump, it is gravity fed. it is a 1994 zx2r. I just replaced the spark plugs, but im not sure of the strength of the spark. How do i check this? It could be coil related i guess, is there a way to check this? Finally, i know the choke works, as ONCE i do get the bike started, i use it to keep the bike going for 20-30 seconds before taking it off, and i notice the revs drop back down to idle.

[kevindinho]

Hi fellow zxr250 owner!


My starting technique is (usually after leaving the bike untouched for more than two weeks):
- Full Choke
- Throttle and starter button until it starts (can take 5-10 seconds but it always fires up) it shouldnt be hard to start if you leave it over night.
my mates zx2r is a 94 model i believe and he finds it hard to start at first but with choke + throttle i always get it started. Dont be shy on the throttle and choke.

If i leave the bike and wait 5-10mins, and try and start it again, usually it can start straight away. ).

yea it does sound like its flooded, my bike used to be hard to start, the spark plugs used to flood if i start the bike and not ride it. The dealers who i bought it off replaced
- fuel tap
- Rebuilt carbies
- serviced it and replaced spark plugs etc like 10 times
- ended up being a issues with wrong main jet size.

As for my mates one, it was in pretty bad condition when he bought it. Smoke coming out etc, he cleaned the carbies and it runs good atm. Dunno if that helps, just trial and error i guess. Start with cleaning the carby if you have replaced the spark plugs already.

Cheers
Kev

[oldman]

Your spark plugs are fucked. Change them and it will start like a wet dream.

[zx2r1994]

kevindinho - ive tried different combos in trying to start my bike, used full choke + throttle etc. still having trouble. Thankfully, im not getting any smoke blowing out once i get it started. A few people have suggested it might be flooded - what causes this to happen? Im assuming, getting the carbs rebuilt would fix the flooding issue?

oldman - thats what i thought as well, so i changed the spark plugs over to new NGK ones, but im still having the problem. I might take them out again and check the conditon, and also check the spark strength (anyone know how to do this? )

Hopefully i can take the bike in to a workshop to get the cam chain/tensioner fixed and get the carbs rebuild - hopefully it will fix her up (fingers crossed)

but keep the suggestions coming!

[dilligaf]

if you're lucky putting a carb cleaner through it might work
http://www.nulon.com.au/products/Total_ ... m_Cleaner/

[oldman]

Low compression will cause the same problem, won't start when cold but appears ok once started. I would check the compression before I went to far. To check the spark strength just grab the spark plug wire and crank it over, lol . Actually take the sprk plug out and hook the wire up to it and make sure the spark plug is grounded and look at the spark. It should be dark blue and very much noticable. Otherwise you would probably need to take it to a mechanic that has a device for checking that, as modern ignitions put out up to 80,000 volts to the spark plugs. DO NOT crank the motor with a spark plug wire unplugged or do the previously mentioned test without the spark plug grounded, the high voltage will backfeed and you will blow your electronic ignition. Good luck.

[robracer]

just grab the spark plug wire and crank it over

thats a low act old dude
I need a good laugh anyway so make sure you have a friend capture it on video & post it up here

[craig]

they are old bikes and generally riden hard and badly maintained by inexperienced riders... (for riden hard read badly)
there is always the failed ignition connection .....my main re-ocurring ignition problem
try cranking up the idle by half a turn... touch of choke and not much throttle till it starts ....
cranking idle to start will leave you two km down the road with an over reving monster .....carb balance may also help...try the S&W ball bearing method its close to true adjustment
top end noise may not be cam adjuster but valve clearances......that may also inhibit ignition
all else fails keep pushing the f##**R down the road till it starts or you have cardiac failure..its worth it