Stuck throttle bodies?

[ccew]

Hi folks,

It was finally a nice day out, so i went home at lunch to get the bike. I had test driven it a few days ago with no issues. Anyway, I got to the highway with no issues, then once on it and picking up speed, I suddenly had no power. RPMs stuck around 4K and wouldn't go any higher and no lower than 3K. It maxes at 5k only ~100 kph in 6th and won't go any faster.

Likely cause: Last night, I took apart the throttle cable housing to lube the cables. Put it all back together and adjusted tension properly, no issues. So I suspect theres something binding somewhere. I can see from the where the cables attach at the throttle body, the cables are properly seated. I can also see that the wheel that they are set in, will not go back to the stop (hence the constant revs i believe). The throttle at the grip seems to snap back freely.

I had stopped at an exit on the highway to have a look. Took apart the throttle pod and the cabels seemed fine...no slack, no binding. I made it to work safely, but I want to fix it before i set off.

Any thoughts? Doesn't make sense to me.

 

[FinalImpact]

Hi folks,

It was finally a nice day out, so i went home at lunch to get the bike. I had test driven it a few days ago with no issues. Anyway, I got to the highway with no issues, then once on it and picking up speed, I suddenly had no power. RPMs stuck around 4K and wouldn't go any higher and no lower than 3K. It maxes at 5k only ~100 kph in 6th and won't go any faster.

Likely cause: Last night, I took apart the throttle cable housing to lube the cables. Put it all back together and adjusted tension properly, no issues. So I suspect theres something binding somewhere. I can see from the where the cables attach at the throttle body, the cables are properly seated. I can also see that the wheel that they are set in, will not go back to the stop (hence the constant revs i believe). The throttle at the grip seems to snap back freely.

I had stopped at an exit on the highway to have a look. Took apart the throttle pod and the cabels seemed fine...no slack, no binding. I made it to work safely, but I want to fix it before i set off.

Any thoughts? Doesn't make sense to me.

As best I understand, you can see and hear the throttle plates snap back with a crisp closure. What I am not clear on is if you took it apart after the issue or you had it apart and perhaps caused the issue.

If you lift the fuel tank and remove the screws holding the air filter lid on, you have direct access to see the throttle plates. They should track the grips movement dead on. I will say that if you adjust the return slack on the cable such thats its TOO TIGHT IT WILL BIND THE THROTTLE!


At idle:

WOT:

Air Box lid removed: Looks at throttle plates (brass)...

If for some reason there is a vacuum hose off. The throttle plates could be fine but the engine would idle high. IT WOULD RESPOND to Throttle inputs though by going up with this caveat: there is a sensor for engine vacuum. If that sensor is not connector or has a massive vacuum leak, the ECM will not fuel the engine properly so inspect the vacuum hoses at the throttle bodies.

[MENTION=5263]SANGER_A2[/MENTION] this should give an idea of the hose ends which need tracked down.

Green is coolant - all other colors are suspect including the clamps at the throttle body base (not shown in this picture but is above in photo). The blue indicates components that could possible crack. Unlikely, but worthy of inspection IMO.

Parts by name and PN: Yamaha FZ6 07 Full parts catalog | Joisey Boyz Gastronomical Society

MORE PICTURES FROM ANOTHER THREAD:

Top of the pic; see those small hoses coming from the base of the Throttle bodies? There is one for each TB. They usually pair off, two on one side and two on the other. Each SHOULD have a plug in it to seal the end of it.

Follow them and confirm each is plugged.
HERE: See the GREEN Connector, see the WHITE connector, to the right of these two connectors is a hose. On the end of that hose is a plug. The hose has a pink stripe on it. That is what your looking for! THere are FOUR of them. Notice straight across on the other side (TOP OF PHOTO) is another that is visible.

But, the goal here is to FOLLOW EVERY hose and confirm its not sucking air some where. Hence the TUBE to the EAR. At idle you may be able to hear a vacuum leak.

Then, check these - make sure they are tight:

 

[ccew]

Thank you sir!

Yes during the winter I took it apart for the naked conversion. after having it all together I had takien it out of the garage to start it up. Everything was fine. Last weekend's little road test ride, also fine.

All I did last night was disconnect the cables to lube them and then put it back together.

I'll check the plates to see if they are closing there's something blocking them.

At idle, in your pic, it does not sit against the stop. It's about 1/4" away and wont go back even if I force at the throttle grip (i.e. twist forward). I know this is a really simple solution somewhere and it's me that did something stupid....likley right in front of me...I'll check at end of day...then work through the list you provided....I'm familiar with the synch tubes etc...I think it's definiately mechanical though. fingers crossed.

 

[FinalImpact]

Thank you sir!

Yes during the winter I took it apart for the naked conversion. after having it all together I had takien it out of the garage to start it up. Everything was fine. Last weekend's little road test ride, also fine.

All I did last night was disconnect the cables to lube them and then put it back together.

I'll check the plates to see if they are closing there's something blocking them.

At idle, in your pic, it does not sit against the stop. It's about 1/4" away and wont go back even if I force at the throttle grip (i.e. twist forward). I know this is a really simple solution somewhere and it's me that did something stupid....likley right in front of me...I'll check at end of day...then work through the list you provided....I'm familiar with the synch tubes etc...I think it's definiately mechanical though. fingers crossed.

Notice the bottom cable is your throttle control. The top is the return. I think the top cable is Fixed (can't change position). You must adjust them to obtain the following:
Free play from the grip to the TB (so you can steer and not change throttle input).
Free play from Throttle Pull to Throttle Return. One cable must always have slack in it! Throttle free play from the GRIP to the TB shaft is one thing.
Free play from the Return cable is another.

Technically it doesn't need the return cable - its more of an insurance policy to force it closed. But the two must have slack because one is pulling it open and the other is pulling it shut. If too tight - (NO SLACK between the two) it just jambs!

Be safe!
Notice the little bit of droop in the cable.

 

[ccew]

Ok...I'll recheck the slack. I may disconnect the cables again to ensure the plates can close...That will at least narrow the issue down, and if i start it...it should idle normally as well.

Thanks again.

 

[ccew]

Ok. In a word, STUPID. Yeah that's me. Post me on the wall of shame. I hadn't removed the rags from the tubes when I took it all apart to retract the wires into the frame for the naked conversion. At low speeds the suction wasn't enough to pull them down. Once I hit the highway, down they went and blocked the plates open. Twit. Thanks FI for the help.


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[TownsendsFJR1300]

Ok. In a word, STUPID. Yeah that's me. Post me on the wall of shame. I hadn't removed the rags from the tubes when I took it all apart to retracted the wires into the frame for the naked conversion. At low speeds the suction wasn't enough to pull them down. Once I hit the highway, down they went and blocked the plates open. Twit. Thanks FI for the help.


Sent from my iPhone using Tapatalk

$hit happens!! No foul, no harm!

 

[motojoe122]

I'm glad it wasn't any worse than that!

 

[FinalImpact]

Glad you and bike are OK! Don't be too hard on yourself and alway take some time and look things over before buttoning things up!

Be safe! :thumbup: