Random high revving during stop

[dontgiveajack]

I noticed in your first thread you mentioned you were buying a 2009 Ninja 250r with an aftermarket exhaust. This is the same bike?
Which aftermarket exhaust? Full or slip-on? Re-jetted/shimmed by the previous owner? What other mods were done on the bike?
Do you have any other symptoms, other than the idle spiking? How frequent does the spiking occur?



I would first adjust the idle to the setting as per the manual, and see if the bike idles better. Report back.

Yup, same bike. Not totally sure if it's a full or slip-on; how do you tell? As for re-jetting/shimmed: no idea either! This is the only technical mod done to the bike AFAIK. The fender was cut/filed down and frame sliders were added.

I'm going to be riding her tonight so I'll report back with the other things. From my memory, the spiking occurs every other stop almost. I remember it happening quite often last weekend.

Thanks again for all the suggestions.

[SLaP]

Yup, same bike. Not totally sure if it's a full or slip-on; how do you tell? As for re-jetting/shimmed: no idea either!

Is there a name/make on the side of the exhaust? Take a picture of the exhaust and post it.

I'm going to be riding her tonight so I'll report back with the other things. From my memory, the spiking occurs every other stop almost. I remember it happening quite often last weekend.

Remember to adjust the idle speed and see if it gets better.

Have a good ride!

[dontgiveajack]

Okay, I really paid attention to the problem now and it isn't as I described.

The high RPM's occur when I am in first or even second gear and give a little throttle, then immediately close the throttle. However, when I close the throttle, the RPM stays at whatever RPM I got up to in those respective gears despite the throttle being completely closed and even if the clutch is held in.

Is that normal behaviour?

[SLaP]

Remember to adjust the idle speed and see if it gets better.

Did you try this?

Turn it so that it idles at 1250-1350 rpm at running temperature. Then report your findings.

[dontgiveajack]

Yup, I remember clearly the idle was around 1700 at operating temps.

Then, while sitting at the red light, I gave it a little throttle to 3000 - 4000 RPM (while in 1st gear, with clutch held in), then closed the throttle, but the RPM's stayed at the 3000 - 4000 until I let out the clutch a bit: then it went back down and stayed there.

[SLaP]

When the bike is not running, if you twist the throttle and then let go...
- Does it snap back to closed quickly?
- Does it move back part way then slow down?
- Does it just move slowly?

If the snap back is not immediate, take a look in the user manual about how to check the throttle grip play and adjust if necessary.

http://www.kawasaki-techinfo.net/sho...9&lang_code=EN

102 Maintenance and adjustment
Throttle Control System


Have you lubed your throttle cable before?

[dontgiveajack]

I will check the snap back tonight. However, when I give it a little throttle and forcibly close it, the RPM's stay at wherever I revved it to (in 1st gear with clutch in).

Never lubed before but I would like to. Any suggestions on the type of lube? I read about silicon before on these forums but seems like everyone has their own.

[SLaP]

I will check the snap back tonight. However, when I give it a little throttle and forcibly close it, the RPM's stay at wherever I revved it to (in 1st gear with clutch in).

1. The cables could be binding because they are dry (Cable lube will fix this)
2. The cables could be binding because they are not routed properly (Make sure they are routed properly)
3. Throttle return spring on the carb is damaged (Inspect/replace)

Get the shop manual for your bike. Read up on inspecting throttle control system and lubing the cable.

I would verify this before looking at issues with the carbs etc.

Never lubed before but I would like to. Any suggestions on the type of lube? I read about silicon before on these forums but seems like everyone has their own.

There are many brands and types... I use PJ1 Cable Lube.
http://www.motorcycle-superstore.com...WT.MC_ID=10010

[Scuba Steve]

Is the choke on you say it stars without it which makes me think you are leaving it on all the time or else it wouldnt start. Off is pushed toward the front of the bike.

[Brian P]

Yup, I remember clearly the idle was around 1700 at operating temps.

Fer crissake THAT IS TOO HIGH and this is your entire problem and you've already been told this several times.

Forget everything else, set warm idle speed to 1400 rpm as per factory specifications and then tell us what happens.

[SLaP]

OP... Brian is correct. The manual does state that. http://www.kawasaki-techinfo.net/sho...9&lang_code=EN

106 MAINTENANCE AND ADJUSTMENT

Idle Speed
1250-1350 r/min (rpm)

[ZX600]

NO It won't....under load the RPM will drop.....

Cool, thanks, I learned something