Engine stays revved issue?

230 Views 8 Replies 3 Participants Last post by Jet Munro, 13 d ago

Jet Munro

Discussion Starter · 17 d ago

I need some help with diagnosing this weird issue.
My bike will not return to idle in most cases. The only way I can get the rpm to drop back down is by quickly opening and closing the throttle forcefully. If I hold the throttle open for just a second and then let go, the engine stays at that rpm or even sometimes will rev up on its own. I’ve looked everywhere for a solution and taken apart the bike many times. I’ve tried adjusting the APS sensor, taking out the throttle body and cleaning everything, checking for vacuum leaks, and so on.

The weird thing is when I go into diagnostics mode, modes 1, 13, 14, and 15 all show 16 at closed throttle. But as soon as I touch the throttle it goes to 20 and won’t drop down unless I snap the throttle open and closed. So it seems that the throttle plates are not fully closing which may be causing the issue. I’ve tried forcing them close while the bike is running to see if allows the engine to drop back to idle. But the servo motor won’t let me push them closed. At this point, I’m guessing maybe there is an issue with the TPS or APS but I don’t know how to know for sure.

Save

1 - 9 of 9 Posts

Intuit

· #2 · 15 d ago

Re 16 vs 20 reading, lube your throttle cable.

HOW TO: Lube Throttle Cable on R6

NOTE: The general idea works for clutch and brake cables as well. Scoured the internet checking all kinds of forum threads, websites, videos and never found an effective solution for the R6. Here is a quick, effective solution that doesn't involve special tools or decoupling cables...

www.r6-forum.com

I'd stay well away from the "chain and cable" lube products as they're sticky/tacky in nature... just the opposite of what one wants or needs on a throttle/clutch cable or drive chain.

Does it behave differently with cold engine versus hot?

Does it idle around 2k on cold and around 1400 warm?

Save

Jet Munro

Discussion Starter · #3 · 15 d ago

Intuit said:
Re 16 vs 20 reading, lube your throttle cable.

HOW TO: Lube Throttle Cable on R6

NOTE: The general idea works for clutch and brake cables as well. Scoured the internet checking all kinds of forum threads, websites, videos and never found an effective solution for the R6. Here is a quick, effective solution that doesn't involve special tools or decoupling cables...

www.r6-forum.com

I'd stay well away from the "chain and cable" lube products as they're sticky/tacky in nature... just the opposite of what one wants or needs on a throttle/clutch cable or drive chain.

Does it behave differently with cold engine versus hot?

Does it idle around 2k on cold and around 1400 warm?

Thanks for the suggestion! Ok I can absolutely try to lubricate it. It’s a brand new throttle cable so I didn’t think I had to.

It does seem to act differently cold vs. hot. When it’s hot it will get stuck at much higher rpms and actually start revving up a little bit more on its own. When it’s cold it only really seems to get stuck at very low rpm. But this is all happening in neutral in my garage while I’m working on it. I’ve tried to ride it a couple times and it’s almost as if I have cruise control. I don’t think I’ve tried to ride it when it was cold though.

Also, the throttle has two cables. A push and a pull. So I kinda doubt it’s any issues with my throttle cable since it is brand new and I know that I’m pushing the the throttle back all the way closed when the problem happens. I will say though, this issue seems to only have started after I replaced the throttle cable so it seems like I messed something up but can’t figure out what it is.

And my Tachometer isn’t working either so I can’t see what rpms it’s idling at. But it does idle high when cold and then drop down to what sounds like around 1000+ rpm. By the way, it’s a 2006 so it is fuel injected.

See less See more

Save

Intuit

· #4 · 14 d ago

Cold bike, make sure the cable doesn't move the throttle plates when you turn the steering head lock-to-lock.
Also make sure that it's routed according to diagrams in the manual.

This thread covers the auto-choke function, and how to calibrate it.

R6 2005 - Idle RPM increases as engine heats up

Hello, this is my first time on this forum. Im having some issues with my Yamaha R6 (2005) after winter storage, everything worked fine last summer. The motorcycle was placed on the back of a car trailer with roof for about 5 months. I topped of the fuel tank with fresh gasoline before...

www.r6-forum.com

Without an accurate and near-precise tach reading, I'm not sure how you can properly tune the bike. Just going by sound alone would be tricky unless there's another for equal reference.

Save

Intuit

· #5 · 14 d ago

Does the tach do the normal sweep as it powers up?

Save

Panici

· #6 · 13 d ago

Jet Munro said:
I will say though, this issue seems to only have started after I replaced the throttle cable so it seems like I messed something up but can’t figure out what it is.

DING DING we have a winner.

Take it all apart and try again. Maybe you can find a service manual that details the process instead of just watching a youtube video?

Save

Jet Munro

Discussion Starter · #7 · 13 d ago

Intuit said:
Cold bike, make sure the cable doesn't move the throttle plates when you turn the steering head lock-to-lock.
Also make sure that it's routed according to diagrams in the manual.

This thread covers the auto-choke function, and how to calibrate it.

R6 2005 - Idle RPM increases as engine heats up

Hello, this is my first time on this forum. Im having some issues with my Yamaha R6 (2005) after winter storage, everything worked fine last summer. The motorcycle was placed on the back of a car trailer with roof for about 5 months. I topped of the fuel tank with fresh gasoline before...

www.r6-forum.com

Without an accurate and near-precise tach reading, I'm not sure how you can properly tune the bike. Just going by sound alone would be tricky unless there's another for equal reference.

The cable is routed correctly just as the manual shows and moves very smoothly. It doesn’t feel sticky whatsoever and is very snappy. Also does not move the throttle plates.

Thanks for sending me that thread. I looked at it and there’s some really good information that I’ll look more into. But it’s a totally different issue than what I’m having. In fact I haven’t seen anyone with a similar issue to mine. The bike idles just fine. It’s only when I mess with the the throttle that it gets stuck. It doesn’t idle at a high rpm but instead it acts like it has a cruise control when I slowly let off the throttle at whatever rpm I’m at.
And yes it would really help to have a working tach. Hopefully I can figure out what’s wrong with it. I’m tempted to just buy a whole new ecu.

Save

Jet Munro

Discussion Starter · #8 · 13 d ago

Intuit said:
Does the tach do the normal sweep as it powers up?

Yes it does. So it’s getting power. But it hasn’t worked since I got the bike so I don’t know what caused it to stop working.

Save

Jet Munro

Discussion Starter · #9 · 13 d ago

Panici said:
DING DING we have a winner.

Take it all apart and try again. Maybe you can find a service manual that details the process instead of just watching a youtube video?

Haha yeah I might try it again. I’ve taken it apart twice now to try to figure it out. There really is no YouTube video or instructions out there that I could find for my bike. And the service manual just talks about what the YCC-T system does and its components. Ive used that along with pictures to try to make sure everything looked right. As far as I can tell it’s all put together correctly. If I could find a more detailed exploded view or some disassembly/assembly instructions I would try it again.
The weird thing is when I go into diagnostics mode and look at the TPS and APS inputs and try to replicate the problem, I can’t see anything wrong. Sometimes though, it will show 20 as fully closed when it usually shows 16. Both numbers are still in the appropriate range though so that may not be the issue. So I can only replicate the problem when the bike is running. And when the bike is running I can see the throttle plates getting stuck and I can’t force them closed. There must be an issue with the YCC-T system other than the TPS and APS sensors, throttle cable, and servo motor, since all are working fine it seems.
These are my thoughts right now but I realize I’m missing something so I appreciate all your suggestions!

See less See more

Save

1 - 9 of 9 Posts

Top Contributors this Month