Hot start issue, please help!!
Hello all, my names damian and im new to the forum.
So i recently aquired a 2002 zx12r with roughly 14k miles, the engine build seemed pretty extensive, je +3mm pistons, built/ported head, cam gears, nitrous, air shifter, myrtle west swingarm, pc3r, msd launch control, etc etc
the bike starts up cold just fine, little hesitation, but after maybe one or two cranks (@35 degrees) she fires up and idles great. once she is up to temperature i will have slight hesitation from idle to 2500-3krpm then she starts pulling wonderful.
my problem is when this bike is at normal operating temperature i will shut it off, go to start it again and it will chug slower than normal like a bad battery almost, or like the ignition timing is too far advanced. But if i let the bike cool down it will start up no problem. today while trying to do some diag i was riding it around the block a couple times and temp got to about 3/4 and then as i was about to shut it off the fans kicked on.
This is driving me nuts trying to figure it out, battery, rectifier, stator are all new and wired correctly.
so heres a question, this problem leads me to advanced timing possibility, too advanced keping it from being able to hot start
Does the coolant temperature sensor have anything to do with timing or fuel on these bikes, is there a diag procedure to test these on the bike (resistance values etc)
the bikes tune is a mess on the power commander 3r, and in cell 0% throttle 500rpm it shows a fattening of 5, which doesnt seem normal to me. i dont want to erase the map and start over, but if i was to post the map would someone be able to tell me if it looks right on a larger bore zx12?
i apologize for the long post but im trying to provide as much info as possible for you kawasaki gurus to shed some wisdom on me, wanted to say thank you in advanced and i hope i can find the answers to my woes.
So i recently aquired a 2002 zx12r with roughly 14k miles, the engine build seemed pretty extensive, je +3mm pistons, built/ported head, cam gears, nitrous, air shifter, myrtle west swingarm, pc3r, msd launch control, etc etc
the bike starts up cold just fine, little hesitation, but after maybe one or two cranks (@35 degrees) she fires up and idles great. once she is up to temperature i will have slight hesitation from idle to 2500-3krpm then she starts pulling wonderful.
my problem is when this bike is at normal operating temperature i will shut it off, go to start it again and it will chug slower than normal like a bad battery almost, or like the ignition timing is too far advanced. But if i let the bike cool down it will start up no problem. today while trying to do some diag i was riding it around the block a couple times and temp got to about 3/4 and then as i was about to shut it off the fans kicked on.
This is driving me nuts trying to figure it out, battery, rectifier, stator are all new and wired correctly.
so heres a question, this problem leads me to advanced timing possibility, too advanced keping it from being able to hot start
Does the coolant temperature sensor have anything to do with timing or fuel on these bikes, is there a diag procedure to test these on the bike (resistance values etc)
the bikes tune is a mess on the power commander 3r, and in cell 0% throttle 500rpm it shows a fattening of 5, which doesnt seem normal to me. i dont want to erase the map and start over, but if i was to post the map would someone be able to tell me if it looks right on a larger bore zx12?
i apologize for the long post but im trying to provide as much info as possible for you kawasaki gurus to shed some wisdom on me, wanted to say thank you in advanced and i hope i can find the answers to my woes.
1 - 12 of 12 Posts
Do you have any way of checking your afr as the bike is running? Also consider that if it's cammed the idle will be affected
I was going to be installing an afr gauge, sooner than later. I haven’t yet.Do you have any way of checking your afr as the bike is running? Also consider that if it's cammed the idle will be affected
My idle is fine, it just won’t start when hot, that’s my main concern
Well if the bike can't start when hot then the idle is most likely also not good while hot, you did state it would "chug" while hot. Having a wideband Guage can help to determine whether maping is one of the issues. Also, have you checked your coils and plugs? Coils can sometimes perform worse under hot temperatures, and it's free to check them as long as you have a multimeter. As for your mapping i personally never touch anything below idle (1000-1500 my bike) or the 0% throttle column however my engine is not as moded as yours, some of the more experienced 12 owners here on the forum would be the ones to know as wether that is normal given your build.I was going to be installing an afr gauge, sooner than later. I haven’t yet.
My idle is fine, it just won’t start when hot, that’s my main concern
By chug I meant it would turn over very slow, imitating a bad battery or too much advanced ignition timing. Whereas when the bike is cold (before running it and after running it and letting it get back down in temperature) it starts up very swiftly with no hesitation. I agree that I need to get an afr reading. And would make sense to have a gauge on the bike as a permanent fixture.Well if the bike can't start when hot then the idle is most likely also not good while hot, you did state it would "chug" while hot. Having a wideband Guage can help to determine whether maping is one of the issues. Also, have you checked your coils and plugs? Coils can sometimes perform worse under hot temperatures, and it's free to check them as long as you have a multimeter. As for your mapping i personally never touch anything below idle (1000-1500 my bike) or the 0% throttle column however my engine is not as moded as yours, some of the more experienced 12 owners here on the forum would be the ones to know as wether that is normal given your build.
But to clarify, it has all new plugs and coils, as well as battery, stator, regulator/rectifier, and high torque starter.
Compare your bat voltage when hot vs when cold, it's the best recommendation I can give you
Remove the pc3r, then see how it runs. A lot of them are known to cause problems.
Does it have a manual timing advancer ? Pull the crank trigger cover on the right side to see.
disassemble the starter and check the brushes?
86mm pistons may be 13:1 compression. Do you have a battery with enough amperage?
does the crank have added stroke? To tell quickly, is there a large spacer/shim between the block and case?
what are the cams degreed to? What cams are being used?
have you checked the starter solenoid, cables and ground? No corrosion
Handle bar start switch needs to be clean and make sure all the contacts are good.
when it’s hot, use a regular car battery and jump start at the starter. This will provide plenty of amperage. If it spins and starts then you know you need a stronger battery?
just some things to check.
cmg
disassemble the starter and check the brushes?
86mm pistons may be 13:1 compression. Do you have a battery with enough amperage?
does the crank have added stroke? To tell quickly, is there a large spacer/shim between the block and case?
what are the cams degreed to? What cams are being used?
have you checked the starter solenoid, cables and ground? No corrosion
Handle bar start switch needs to be clean and make sure all the contacts are good.
when it’s hot, use a regular car battery and jump start at the starter. This will provide plenty of amperage. If it spins and starts then you know you need a stronger battery?
just some things to check.
cmg
Any pictures?? Bike sounds like a nice piece !
cmg
cmg
Just a comparison. My 1361 zx has bigger bore and stroke. Timing is advanced in the ecu. (Scott Davis flash) no advance down low. 415”/265° cams
13:1
starts fine when hot. I am using a AG801 240 amp battery. All cabling and switches are stock. Made sure the battery box connections are clean and tight.(I did bypass the ignition with a woodcraft zx14 ign delete)
cmg
13:1
starts fine when hot. I am using a AG801 240 amp battery. All cabling and switches are stock. Made sure the battery box connections are clean and tight.(I did bypass the ignition with a woodcraft zx14 ign delete)
cmg
When I had this problem started fine cold once it got hot turned really slowly and would not start. Once in a while I could role start it. Here is the fix I used. zx12r service manual and in sections 16-96 and 16-97 I saw that there are relays in the junction box. I ordered one off ebay for 9.99 shipped. Didn't want to pay the $140 for a new one if it didn't work. part number 26021-1089 (the one that came out of my bike was 26021-1106) seem to be the same fuse box plugged right in and the bike ran great. Box is right in front of the fuel cap. Take off the plastic cover (looks like the gas tank, But we know the gas tank is really under the seat) and it is plug and play.Hello all, my names damian and im new to the forum.
So i recently aquired a 2002 zx12r with roughly 14k miles, the engine build seemed pretty extensive, je 3mm pistons, built/ported head, cam gears, nitrous, air shifter, myrtle west swingarm, pc3r, msd launch control, etc etc
the bike starts up cold just fine, little hesitation, but after maybe one or two cranks (@35 degrees) she fires up and idles great. once she is up to temperature i will have slight hesitation from idle to 2500-3krpm then she starts pulling wonderful.
my problem is when this bike is at normal operating temperature i will shut it off, go to start it again and it will chug slower than normal like a bad battery almost, or like the ignition timing is too far advanced. But if i let the bike cool down it will start up no problem. today while trying to do some diag i was riding it around the block a couple times and temp got to about 3/4 and then as i was about to shut it off the fans kicked on.
This is driving me nuts trying to figure it out, battery, rectifier, stator are all new and wired correctly.
so heres a question, this problem leads me to advanced timing possibility, too advanced keping it from being able to hot start
Does the coolant temperature sensor have anything to do with timing or fuel on these bikes, is there a diag procedure to test these on the bike (resistance values etc)
the bikes tune is a mess on the power commander 3r, and in cell 0% throttle 500rpm it shows a fattening of 5, which doesnt seem normal to me. i dont want to erase the map and start over, but if i was to post the map would someone be able to tell me if it looks right on a larger bore zx12?
i apologize for the long post but im trying to provide as much info as possible for you kawasaki gurus to shed some wisdom on me, wanted to say thank you in advanced and i hope i can find the answers to my woes.
1 - 12 of 12 Posts
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