Jump to content
MatthewG

Higher idle then usual when hot

Recommended Posts

MatthewG

Hi guys, bought a brand new fz07 in june and am now at about 2500 kilometers.

 

Yesterday it started idling a bit higher then usual when im at red lights. It does not do it all the time either but it only seems to happen when the bike is nice and hot. I could hear the bike is idling higher, around 1350-1400 compared to the usual 1150-1200 rpm range on idle.

 

Could it be my throttle bodies need adjustment ? Because according to the manual the sync should be performed at the initial 1000 kilometer oil change and everything else but I skipped the throttle body synch.

 

Thank you very much !

Share this post


Link to post
Share on other sites
Beemer

Is it hotter than usual outside? Mine behaves differently when it's hot out but I believe that's just normal.

Share this post


Link to post
Share on other sites
MatthewG
5 minutes ago, Beemer said:

Is it hotter than usual outside? Mine behaves differently when it's hot out but I believe that's just normal.

It's been really hot here for the last 2 months... 32-38 degrees celsius. on the daily. Yesterday was around 31 degrees celsius.

 

I mean it's never acted like this before... I find it strange it would start doing that just now don't you think ? 

Share this post


Link to post
Share on other sites
rick

throttle sync should not effect idle speed - the ecu does this. If one is way off, you'll more likely have some off idle smoothness issues. Can't hurt to check though. They are usually pretty good from the factory.

 

A fully warmed up motor is always gonna be hotter than the ambient temp. Not sure why that would have an effect unless the hot motor is causing something (like the throttle plates) to stick or the air temp sensor is faulty.

 

Have a look at the rubber plug on the right TB and the hose on the left one and make sure they are making a seal. A big air leak can cause the idle to increase. 

 

Make sure the throttles are closing completely - proper cable freeplay.  And when it's hot, have a look at where the linkage hits the throttle stop screw - gonna recommend you not mess with that screw. If a small amount of pressure at the linkage there causes the idle to drop back to normal, your butterflies are not closing completely. you might have some goo built up on the plates and the throttle bores, but at 1500mies, I would think that unlikely. 

 

If finding it isn't easy, it's under warranty - let the dealer mess with it. 

Share this post


Link to post
Share on other sites
Beemer
1 hour ago, MatthewG said:

It's been really hot here for the last 2 months... 32-38 degrees celsius. on the daily. Yesterday was around 31 degrees celsius.

 

I mean it's never acted like this before... I find it strange it would start doing that just now don't you think ? 

This bike has been quirky since I bought it and little things just happen out of nowhere at times and sometimes never surface again. Sometimes mine idles extra high for a couple seconds when I first fire it up but it settled down quickly. I may be different than you when it comes to such things because after the first quirk with this bike I expected more to appear (also, all my bikes have had weird behaviors but nothing that hurt anything) so the little quirks don't come as a surprise to me. If I think something is going to hurt the bike I will act on it. If it concerns you this much maybe you should have it looked at for your personal comfort.

Share this post


Link to post
Share on other sites
rick
18 hours ago, Beemer said:

Sometimes mine idles extra high for a couple seconds when I first fire it up but it settled down quickly.

That's perfectly normal. The colder the ambient temp, the higher the idle will be as the mixture must be leaner to keep the motor running. If you lived in a place where it actually got cold 😉 you'd see this for a longer period of time and at a higher RPM. 

 

Carb choke levers and enriching circuits are now replaced by the ecu controlling an Idle air control valve and injectors. The result is a fast idle for a short time after start-up when cold. As for while running at an ambient 100F (38c) , that's not right. 

 

  • Like 2

Share this post


Link to post
Share on other sites
MatthewG
43 minutes ago, rick said:

That's perfectly normal. The colder the ambient temp, the higher the idle will be as the mixture must be leaner to keep the motor running. If you lived in a place where it actually got cold 😉 you'd see this for a longer period of time and at a higher RPM. 

 

Carb choke levers and enriching circuits are now replaced by the ecu controlling an Idle air control valve and injectors. The result is a fast idle for a short time after start-up when cold. As for while running at an ambient 100F (38c) , that's not right. 

 

The bike was perfectly warmed up... I was waiting a red light in my 25 minute work commute.

Share this post


Link to post
Share on other sites
rick

If you were in a car and the idle popped up when you turned on the AC, that would normal. 

 

I don't think what's happening to your fz is normal. 

Share this post


Link to post
Share on other sites
norcal616

I have noticed since day 1 of my 2015 it can idle at 2 slightly diffrent rpms at red lights in gear... the rpms pick up 200 rpms if i dont pull the clutch lever in enough to rest on my finger... i chalked it up to the safety switch doing something with ECU... 

Share this post


Link to post
Share on other sites
MatthewG

It hasnt redone it so far... bizarre. Ill keep an eye on it.

 

Thanks for your help guys !

Share this post


Link to post
Share on other sites
stickshift

It's perfect normal.

 

When radiator water temperature reaches a critical high point (usually in hot air temperatures and at lower travel speeds) the ECU will inject more fuel to cool the cylinders, as a consequence rpm is raised.

 

Very normal, it does this to assist engine cooling. In our hot Aussie summers we often see this on EFI bikes!

Edited by stickshift

Share this post


Link to post
Share on other sites
rick

Neither of my fuel injected bikes do this - But we don't see 38c here either, even 30c is sorta rare.. 

 

Guess that'll also bump up the water pump speed as well to help keep things cooler. Can't imagine piling on gear to ride in that kind of weather.  

 

My car's idle speed will bump up just by a slight turn the steering wheel while stoped. Guess the extra load on the motor by working the power steer pump wakes up the ecu. 

Share this post


Link to post
Share on other sites
MatthewG

Ok it did it again but I also notice that this happens when the engine reaches high operating temperature (103-106 degrees celsius, fan starts around 104 iirc).

 

What I did was blipped the throttle and the rpm's went back to 1100-1200 rpm range which is normal (from 1300).

 

Share this post


Link to post
Share on other sites
CarGuy7a
On 8/12/2018 at 7:27 PM, norcal616 said:

I have noticed since day 1 of my 2015 it can idle at 2 slightly diffrent rpms at red lights in gear... the rpms pick up 200 rpms if i dont pull the clutch lever in enough to rest on my finger... i chalked it up to the safety switch doing something with ECU... 

Yes check your clutch switch's functionality. This can cause a slightly higher idle in the 1300ish RPM range. I figured this out when I removed mine to install a RSC clutch lever and perch. One thing you do not want to do on this bike when removing the clutch switch permanently is short the wires together (I know I've done it and the bike ran like garbage). When you let the clutch out under normal riding conditions, the switch breaks contact when the plunger is pushed in and tells the ECU to wake the fueling map up and if you remove the switch you will hear this in the idle when sitting at a stop it will idle higher.

 

When you "blipped the throttle" you may have vibrated a sticky contact or loose connection on your clutch switch to make it work correctly.

  • Like 2

Share this post


Link to post
Share on other sites
shinyribs

Good advice here. I can't help with the high idle issue, but definitely synch those throttle bodies. You're not going to damage the engine without  it, but the engine will really appreciate it as far as performance, smoothness and fuel efficiency.

Share this post


Link to post
Share on other sites
rick
5 hours ago, shinyribs said:

Good advice here. I can't help with the high idle issue, but definitely synch those throttle bodies. You're not going to damage the engine without  it, but the engine will really appreciate it as far as performance, smoothness and fuel efficiency.

Yer thinking carburetors. Balancing the idle air screws only effects the motor at idle and just off idle. Once the throttle plates have been opened  (they sit fully closed at idle) those circuits don't do much as the air is now going into the motor past the plates.. 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


×

Important Information

By using this site, you agree to our Terms of Use.