r6, hanging idle when the bike is hot. tight valves?

had this issue come up again on a ss built r6 motor, on SOME tracks this thing runs a bit warm when it is 90+ outside.If the engine temp reaches 100c the idle will hang at 4000rpm. This is a real bummer for corner entry, let me tell you. Like no motor braking. Once the engine cools a bit, it seems to return to a normal idle. On days when the coolant temp stays around 90c or less it's not an issue either.

I have tried lots of stuff, from adding fuel and taking away fuel on the map, to adding/sub. engine braking. Would this be a symptom of slightly tight valves (as the engine does have a lot of hours on it) ? Bike starts pretty easy, and is still quite strong.
I have looked over everything for air leaks, but i am thinking of changing throttle bodies or checking the position sensor?? On a power commander you can easily check the throttle position when plugged in to the laptop, and reset it. I have on 2 occasions had it move from "0" at closed throttle to "1" or "2" % at closed throttle on my other bike. with the YEC ecu i don't think we can check like that .. or can you?

 

Step 1 for me would be check valve clearances before replacing TB's and/or sensors...

 

honestly it is WAY easier to replace the throttle body (and would have a tps on it) but yes, i should check em, however this motor was scheduled for a rebuild before Daytona roc anyway.. it's not easy checkin valves, so was hoping to see if a hanging idle is a symptom of tight valves on a hot motor.

I have never had that issue on my crf450 dirt bikes, and those stupid things need adjusted at 90 hrs or so (about 3 months of riding for me) then they have be replaced shortly after that.. but it just gets hard to start, it never had a hanging idle when the valves were tight.

 

Good point. Maybe try getting the bike very hot (dyno room maybe if you habe access to one) as it sits to replicate the issue. Then swap TB's to see if it fixes it...

Checking the valves was first on my list cause it is a definite number, not a trial and error thing, and would just eliminate one more variable. Too bad it's not a GSXR, you can check valves on those in 20 min start to finish haha

 

In Diag mode what are the values for D:01 & D:14. Has the throttle stop screw ever been touched?

 

You can check throttle position in YEC with the monitor function, but it's a bit flakey.

If you have engine braking values in some cells above 40, the idle will act unusual.

 

never ran more than 20 for engine braking, and dropped to 7 this weekend, but still got the hanging idle. I am gonna see if i can find the throttle position function Rick.

Going to try the diagnostic mode, i have never done it.. Ok, reading through the r6 manual and not seeing how to run self diag. It is not displaying any codes, nor has the engine light come on. I have not touched the tiny idle screw on this bike, i had to replace a throttle body on my other bike after trying that.. but will ask if the idle screw has been moved on this machine (i was 2nd owner but I have raced it for 3 seasons now).
EDIT: I GOOGLED self diag. so reading up on that now.. looks like i push the 2 gauge buttons.
EDIT2: no luck bringing up diagnostic mode on either bike, one has a flashed ECU and other is a YEC ecu.. can you only do this on a stock box? with the ignition on, i hold the select and reset buttons.. held a long time, never got H1 or DIAG to ever show up

I agree John, may try some things and the dyno was the place to replicate if possible to see if we fix it..

 

Yes, hold the two gauge button, during power on, screen will say "diag" (this happens real quic with the YEC, OEM takes about 5 seconds). release and re-hold both buttons til D:01 comes up. pressing Select (upper button) will move up through the values.

D:01 is (1 of 2) TPS (plates) values, D:14 (1 of 2) APS (cables) values.

 

tried holding the 2 buttons. i have sub harness, so i have to unplug the smaller ecu plug and plug in the YEC plug so i can hook up the communication cable to my laptop. I get a "H1" when i turn the key on, then it goes to a flashing "H1" and Er_1 after a few moments.. when i have the normal ecu plug in there (like to run the bike) I get nothing.. i tried holding "select" and "reset" both ways (ecu plugged in normal, and with the communication plug in). Nothin.

I see the Monitor feature and the throttle value in there, but not really sure what to do with it.. i get a 156% value in the Monitor feature under throttle value when i click "start".



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My brother's 05 r1 did this at Road Atl one hot day a couple years ago. Idled like it was on choke/fast idle. It was just low on water/running a little hot. Has not done it since. Strange Yammi thing!

 

not low on coolant, checked that early on.. and just double checked.

 

Hmm. The ECU should be hooked up just like you are running the bike, you are trying to access the ECU's internal diag mode, YEC's also have this. No need for the matching system for this. I am assuming that your ECU is YEC and not a flash (although I believe the flashes still have this also.)

Make sure you hold down both buttons, then turn the key on. (OEM ECU's will display HI instead of temp until DIAG shows, YEC will show DIAG right after powered up.)

Cant say that I have ever seen a Yamaha since they went FI that it doesn't work on. (R7 & GTS not included)

 

I was sure you had, just saying there is something on the R1 that raises idle when low coolant/higher temp. Not sure why? Not sure R6 has anything like that. Good luck. Let us know when you figure it out.

 

for sure... it's pretty annoying.. ! and wish i could get the diagnostic mode to come up.

 

You got a stock ECU you can plug in? All I am try to get is where the TPS and APS are set. When they are at the edge of "spec" they work fine in an OEM condition, but they can do some odd things when other things change, such as built engines and mapping. At Road A this weekend three guys had trouble (08R6 07R1, 09R1), , all were at the low end of the spec. Moving it to the middle of the spec range fixed two, moving another high fixed the other.

 

Monitor won't work with the sub harness unless you do some additional wiring. Forgot that you had that.

 

i have a stock ECU but it wont' run the bike as i have sub harnesses, and i get an error msg.

so with the sub harness and yec ecu, is it possible to get the dash to show a diagnostic mode? In meantime will check the TPS the way shown in the manual.. just need to find two "C" batteries apparently.

 

OK! (well not totally) but i got it to "DIAG" mode.. found you have to hold the 2 gauge buttons FIRST before you flip the ignition on both bikes, flashed ecu and kit ecu go to diag mode now .. gonna go through systems now.

edit: ran through ALL the diag modes, up to d70..
d01: flashes BOTH 15 and 16
d14: shows 16


d1: both 15 and 16 (alternates)
d02: 101
d03:101
d3: 101
d5: 88
d6: 86
d9: 12.7
d13: 16
d14: 16
d15: 17
d21: off
d70: 20


reading the manual, what is the difference in a "fault code" (left side of the charts) and a "diagnostic code no." ??

 

Fault codes are a current failure and are displayed at Key ON. Diag codes are D:01, D:02 etc.. which refers to the on-board diagnostic system. each Diag code is used to check a specific sensor or system. Example: a Fault code 15 (TPS failure) will refer you to Diag mode D:01 & D:13. (the two sensor leads for the TPS)

Try adjusting your TPS (The one that is on the side of the throttle bodies, security torx T25 if I recall) to read 18 in D:01. You can adjust it with the bike powered up. Then retest your hot issues.

 

thanks emry, will give that a go, i did appear (once i finally familiarized myself with this stuff) the tps might be at the edge of a range, nearly out of it.. here were the open throttle values as well.

and the d01: open throttle value was 93 and 94 , closed was 15 and 16
d13: open throttle was 94 (closed was 16)
d14: open was 100 (closed was 16)
d15: open was 100 (closed was 17)

the d05 and d06 i read were temps of the air, and engine coolant.. d09 is battery volts