CF650NK/TK idle speed? raised idle after throttle body clean..

[Wald0]

So i went and cleaned my throttle bodies and after that my idle went from 1200rpm to 1400rpm, and well.. it sounds little too much for me, but it is in the range of the manual.
What is other people CF650's idle speeds?

Manual of CFMoto say 1300 +-130rpm.
while Er6 service manual state 1300 +-50rpm

[ZMC888]

Mine seems to sit a tad low at like 1250, but depends on the angle you view the tach from. Can't find any idle adjust like on a carb bike.

[Wald0]

Mine seems to sit a tad low at like 1250, but depends on the angle you view the tach from. Can't find any idle adjust like on a carb bike.

I think you can adjust idle only by moving those screws what are market with yellow screw lock.. but there is one after where cables connect and one between throttle bodies.. if i got time ( as i definitely have ) and motivation.. (big question mark) i go down and pull everything of once again.

[998S]

So i went and cleaned my throttle bodies and after that my idle went from 1200rpm to 1400rpm, and well..

Wald0, I should NOT tough any of the locked nuts / screws / etc.
You will only go from bad to worse.

I have never seen a NK anything closer then 20 meter, but I presume it has a standard fuel injection, and an injector for each cylinder.

It then probably has an rod connecting the 2 throttle body valves (one side is operated by your accelerator cable, the other valve follows by means of this rod).
This rod is adjusted by the factory (balance of the vacuum), probably has a yellow dotted adjustment nut, don't get that broken.

Then the throttle body where the accelerator cable connects has a stop screw, probably also locked with yellow paint.
Don't break this one either, as the valve opening is pre-set by the factory.
You will screw up settings if you break it, and don't know the base setting any more.
The slave throttle body valve might have a same setting screw, or it might just hang on the connecting rod.

These engine's idle are most likely set by an idle vacuum screw on each throttle body.
Open the screw a bit, mixture will lean out, and the idle will go up. Close it down a bit, and the idle will come down.
Nothing to do with any setting screw (or stop screw) as was the case on carburetor engines.


As you cleaned them, you might have a vacuum leak. Are all rubbers tight?
If a inlet rubber is leaking, it might get some false air, then the idle will go up.
The idle might also drop slower, and other indication of an leak.
Need to check that first before toughing any of the set screws.

You might even have stepper-motor controlling the idle, if that is the case, you can almost be certain you got a leak somewhere.

E.

[Wald0]

'

Wald0, I should NOT tough any of the locked nuts / screws / etc.
You will only go from bad to worse.

I have never seen a NK anything closer then 20 meter, but I presume it has a standard fuel injection, and an injector for each cylinder.

It then probably has an rod connecting the 2 throttle body valves (one side is operated by your accelerator cable, the other valve follows by means of this rod).
This rod is adjusted by the factory (balance of the vacuum), probably has a yellow dotted adjustment nut, don't get that broken.

Then the throttle body where the accelerator cable connects has a stop screw, probably also locked with yellow paint.
Don't break this one either, as the valve opening is pre-set by the factory.
You will screw up settings if you break it, and don't know the base setting any more.
The slave throttle body valve might have a same setting screw, or it might just hang on the connecting rod.

These engine's idle are most likely set by an idle vacuum screw on each throttle body.
Open the screw a bit, mixture will lean out, and the idle will go up. Close it down a bit, and the idle will come down.
Nothing to do with any setting screw (or stop screw) as was the case on carburetor engines.


As you cleaned them, you might have a vacuum leak. Are all rubbers tight?
If a inlet rubber is leaking, it might get some false air, then the idle will go up.
The idle might also drop slower, and other indication of an leak.
Need to check that first before toughing any of the set screws.

You might even have stepper-motor controlling the idle, if that is the case, you can almost be certain you got a leak somewhere.

E.

No vacuum leaks.. did test first with carb cleaner and sprayed all parts and no change in idle.
Yesterday pulled everything to parts even those rubbed mounts that connect throttle bodies to engine if they have some cracks, but they where like new so no cracks.

yes, middle of throttle bodies are screw what you use to adjust vacuum if wanted to do so.

[998S]

You first need to be sure if your bike's idle is controlled by a stepper motor or not.
If you know what that is, you can check it immediately, if you don't know, let me know.

If the bike is NOT controlled so, then you can mark the position of the vacuum setting screws, so you will always be able to return it to the original position (little mark on the side of the screws, little mark on the housing).

You then might want to check the setting, by slowly turning each screw completely in (clockwise).
Count the rotations needed till it hits fully closed (like 1 1/8 turn or so).
I guess it should be anything between 3/4 and 2 1/2 turns.
Write it down for both screws as you will forget it, then set them back to the original postion.

Then, from the original position, with the engine hot, turn them in 1/8 of a turn and see what happens.
Repeat for an other 1/8 turn if needed.
Dont go anything further then 3/4 turn out from full closure, as it might upset your exhaust chemical mix.

Again, I have never seen a NK up close, so the above is very general, and might not be applicable for your bike.
If you basically understand how FI works, you can try this, if not, I should say: get help.

E.

[Wald0]

You first need to be sure if your bike's idle is controlled by a stepper motor or not.
If you know what that is, you can check it immediately, if you don't know, let me know.

If the bike is NOT controlled so, then you can mark the position of the vacuum setting screws, so you will always be able to return it to the original position (little mark on the side of the screws, little mark on the housing).

You then might want to check the setting, by slowly turning each screw completely in (clockwise).
Count the rotations needed till it hits fully closed (like 1 1/8 turn or so).
I guess it should be anything between 3/4 and 2 1/2 turns.
Write it down for both screws as you will forget it, then set them back to the original postion.

Then, from the original position, with the engine hot, turn them in 1/8 of a turn and see what happens.
Repeat for an other 1/8 turn if needed.
Dont go anything further then 3/4 turn out from full closure, as it might upset your exhaust chemical mix.

Again, I have never seen a NK up close, so the above is very general, and might not be applicable for your bike.
If you basically understand how FI works, you can try this, if not, I should say: get help.

E.

Firstly, there is no stepper motor involved.

secondly it looks like 650NK don't have vacuum setting screws at all! only vacuum setting screw is between throttle bodies.
So it looks little different than ER6 throttle body what has those vacuum bypass screws.

Will check today when i take it a part to make sure and this time i will take some photos.

[Wald0]

I made my own vacuum meter or so called Manometer, my throttle bodies where quite a lot out of sync.
it took me some time to get them sync and to get idle down just a little.

but as many things this day was not with out trouble!! I ended having FI malfunction light.. one long and one short, and it is injector 1 short to battery! did change injector from 1 to 2 and 2 to 1 and still same problem.

I did got once injector 1 light but then it was short to ground NOT short to battery and that only came on if i turned power on and before starting bike did WOT and FI error came on.

Tomorrow i have to take multimeter and take a better look.

And yes, bike still runs normally and injectors both click..

[Wald0]

error originated from TPS sensor? if idle was set too low bike gave injector error code.

used almost two days to adjust vacuum and did pretty good job.. minus that too low idle..

had to go and buy new throttle body 2 idle stop screw as old one was too stuck to move!

went to shop and asked screw and they installed it and synced throttle bodies.... and price...?

almost 3 Dollars!! it took them one hour to do it..

Smarter guy would learn something from this........