Horrible low end Torque after Red Line.

[scott123007]

Just a note, Scott...

A rev limiter won't help out at all in any sort of mechanical over-rev condition. Think downshifting into too low a gear at too high a speed. The wheel speed can drag the engine speed much higher than the redline, and indeed do damage just as though it was over-revved under power with no rev limiter.

Some of his symptoms (rough idle, more vibration not cured by normal servicing, no low-speed power, and particularly it getting hot quick) sound remarkably like his *just* hitting/tapping a valve on a piston and bending it just enough it won't seat... Most likely an intake valve in this instance.

I sincerely hope that's not what happened to the OP... But I've seen it, and several times over the years, particularly on customers' bikes who did very similar things as the OP.

Rev limiters will save the valvetrain while under throttle, but chopping the throttle while seriously up in the red range can cause mechanical over-rev conditions. Best thing to do if you get caught in the situation of the OP is to immediately pull the clutch in as you roll out of the throttle so the engine drops RPM as quickly as possible... Don't let the wheel speed drag the engine speed along above the redline.

Just FYI...

Dallara



~

I know all about over revving from downshifting, but that is not what he said he did, so it's not part of this conversation...

Your other point about chopping the throttle "while seriously up in the red range" causing mechanical over rev conditions, is just plain WRONG. No way, no how can that happen by chopping the throttle. LOL (what do you think a rev limiter is doing?)

 

[Ramseybella]

Timing off, Timing chain?

No Smoke, No water in the oil.

Try disconnecting your battery for 30 minutes and hook it up again see if it resets, was an answer to code issues on my 1050 a couple times. :-\

 

[Don in Lodi]

Hmm, what about that extra bit in the cam that does the compression release for start up. Could it have stuck in the activated mode thus releasing compression when it's not meant to?

 

[coastie]

Dang I dont its that sensitive! One trip into the redline would not cause a normal operating motorcycle to malfunction, maybe if the rev limiter was broken. My Tenere has been into the rev limiter a few times, most notably at about 20miles on the odo! LOL...I was use to riding the VFR up around 9k without it breaking a sweat. But weird stuff going on non the less. One person falls over and his clutch explodes, and a few weeks later guy hits a rev limiter and his torque is all but gone.

 

[creggur]

Dang I dont its that sensitive! One trip into the redline would not cause a normal operating motorcycle to malfunction, maybe if the rev limiter was broken. My Tenere has been into the rev limiter a few times, most notably at about 20miles on the odo! LOL...I was use to riding the VFR up around 9k without it breaking a sweat. But weird stuff going on non the less. One person falls over and his clutch explodes, and a few weeks later guy hits a rev limiter and his torque is all but gone.

Did the same a few times after coming off the VFR. My Tenere has been to the rev limiter a few times, no adverse effects. Thoughts that's what the rev limiter was there for?.?.?

 

[GrahamD]

Seriously, it's not a red line thing. It is a manufacturing problem of some description. It just has to be found or "lemoned".

If this bike had a problem with red line, every press bike would be a smoking wreck after a press event.

Something is out of spec. Maybe a small metal shaving in the decompression doohickey, maybe a valve was out of spec and whacked something slightly.

Let YAMAHA do their thing and see what happens.

 

[Rasher]

If this bike had a problem with red line, every press bike would be a smoking wreck after a press event.

Very good point, I have hit mine a few times, but the press are merciless, as are test pilots - who gives a demo bike an easy time :question: Mine is an ex-dem and had 150 miles when I got it, I am sure it was redlined before I took loving care of the bike, but with the Arrow Headers and Flash mine rips up to the red very easily, not my normal style, but when really trying to get a move on I think nothing of taking the bike up to the top of the range.

 

[tubebender]

Hmm, what about that extra bit in the cam that does the compression release for start up. Could it have stuck in the activated mode thus releasing compression when it's not meant to?

::026:: I think Don is on to something here.

 

[coastie]

Timing off, Timing chain?

No Smoke, No water in the oil.

Try disconnecting your battery for 30 minutes and hook it up again see if it resets, was an answer to code issues on my 1050 a couple times. :-\

Yea did it for some reason kick into limp home mode? But yamaha said nothing was wrong with it. Sure enough that would come up on a code.

 

[Dirt_Dad]

I never knew we had a limp home mode. Previously I've only seen that on a Spyder. I saw it a lot on the Spyder, never on a Yamaha.

 

[coastie]

I never knew we had a limp home mode. Previously I've only seen that on a Spyder. I saw it a lot on the Spyder, never on a Yamaha.

I do not know for sure if it does have this mode, I was just asking. I assume that most modern motorcycles with ECU's have it.

Sent from my SAMSUNG-SGH-I747 using Tapatalk 2

 

[GrahamD]

I think there are a few different levels of "limp" depending on what went "limp" if you get my drift.

The clutch switch mod is one version of that. The manual refers to these things often.

 

[pspisk]

Ok gang, here is the update (sorry for the delay).

After 3 weeks in the authorized Yamaha repair facility I was told there is nothing wrong with the bike.

So apparently it is all my imagination and the bike is performing as expected.

But what really infuriates me is after all this time they had it they could not tell me any technical detail whatsoever. I thought they had a Dyno at this facility but apparently that was also a figment of my imagination so they can't tell me if things like lean or rich fuel mixture, torque vs. hp, etc.

Screw all that technical stuff, let's just have several others mechanics ride it and see what they think who needs an exhaust monitoring! Since this isn't a break fix problem, hey it's all great! Starts, runs, don't see a problem here. What a grand waste of my time!

Tomorrow I will call Yamaha and tell them exactly the same thing.

I'm really in awe and I will now be looking to try the "clutch jumper" modification to see if I can get some torque returned to this bike. Can someone please point me to the thread on this? I would also like to try and totally reset the computer so any help with that would also be appreciated.

Thanks..
Paul

P.S. - Good thing I had my Ninja 636 ZX6-R to ride in the meantime.

 

[snakebitten]

Somebody in Virginia, or nearby? This chap needs another S10 to compare to.

 

[Karson]

Somebody in Virginia, or nearby? This chap needs another S10 to compare to.

Was just going to go through the thread and see if someone mentioned this - the only answer at this point.

 

[Ramseybella]

I'm really in awe and I will now be looking to try the "clutch jumper" modification to see if I can get some torque returned to this bike. Can someone please point me to the thread on this? I would also like to try and totally reset the computer so any help with that would also be appreciated.[/b]

http://www.yamahasupertenere.com/index.php?topic=9549.msg158949#msg158949

 

[pspisk]

I may not be the sharpest knife in the drawer but I'm having issues finding the switch, can someone upload a picture where exactly it's located?

Thanks.

 

[Yamaguy55]

Follow the link above. It has photos.

The clutch safety switch/start interlock switch is under the clutch master cylinder, on the side closest to the lever. Follow the wires.

I'd be inclined to use a bore scope and look to see if the valves are bent. If it is an intake valve, you'll be able to see excess blowback in the intake port for that valve in that cylinder. An exhaust would be tougher to find. A proper cylinder pressure test by the dealer would prove it one way or the other.

Page 5-1 in the factory manual spells this out. It is proof one way or the other. If there is a bent valve, stuck decompressor part, etc, it won't pass the compression test. Simple solution, not complex at all.

 

[Ramseybella]

Clutch assembly part number 12 I think, look for a plug with two wires that will be it.

 

[Siseneg]

PM me with your location. We'll sort this out this weekend.
Gary