RPM's increase when clutch is engaged

dcarver · Nov 15, 2011

Put your FJR on the center stand.

Start and put in 1st gear, release clutch.

Use throttle lock to set rpm to approx 1,500.

Disengage clutch and note rpm decrease.

Engage clutch and watch rpm increase.

Crapola. Evidently this board doesn't like iFrame embed code from Vimeo -

so CLICKY

Towards video end, you can see the speedo too.

Weird.

SkooterG · Nov 15, 2011

Bad clutch bearing? Sure makes a racket when you pull in the clutch.

Makes sense though. Not only are you weird, but your FJR is too.

wfooshee · Nov 15, 2011

At 1500 RPM in first there is such a small throttle opening that the difference between driving the rear wheel or not is enough to change the engine speed. Changing the load without changing the throttle results in an RPM change every time. Always.

I'm also assuming that by "disengage the clutch" you mean release the lever, which actually engages the clutch, as in causes it to transmit torque to the transmission. We don't see the clutch lever, we just see the tach and hear the motor. if you actually mean disengage the clutch by pulling the lever, then my explanation goes out the window:

DJB · Nov 16, 2011

I guess the real question is why do we care? If the bike is doing it's job who cares how they programmed the ECU? You need to find more relevant things to rant about.

CAJW · Nov 16, 2011

DJB said:
I guess the real question is why do we care? If the bike is doing it's job who cares how they programmed the ECU? You need to find more relevant things to rant about.

rant/rant/

Verb:Speak or shout at length in a wild, impassioned way.

Noun:A spell of ranting; a tirade.

rel·e·vant/ˈreləvənt/

Adjective:Closely connected or appropriate to the matter at hand.

Synonyms

ertinent - appropriate

ob·ser·va·tion/ˌäbzərˈvāSHən/

Noun:

The action or process of observing something or someone carefully or in order to gain information.
The ability to notice significant details.

I would offer our good DC here is merely offering an observation, not a rant. He has always been a keen observer.

(or maybe a little weird, but aren't we all?)

HotRodZilla · Nov 16, 2011

Um...Carver is a LOT weird. How the hell does one even know this happens? You have snow at your house Don???

BikerGeek99 · Nov 16, 2011

Don - are you high?

Is it Friday yet??

beemerdons · Nov 16, 2011

HotRodZilla said:
Um...Carver is a LOT weird. How the hell does one even know this happens? You have snow at your house Don???

Trust me AJ, it's definitely snowing inside of Carver's head; I mean, it's a fecking blizzard! jes' sayin' and nuff' said!

carlson_mn · Nov 16, 2011

Confused as to what is going on here

Fred W · Nov 16, 2011

dcarver said:
Towards video end, you can see the speedo too.

Yes you can. Is this an early April fools joke? The speedo is only dropping from 25mph to 15mph when the engine speed drops. This kind of suggests that the clutch is not actually being disengaged. :huh:

Spud · Nov 16, 2011

This should immediately be reported to the NHTSA. Under certain circumstances, this problem would lead to serious injury or death. Let's get a campaign started--I'll run home at lunch and see if mine does it too. We need to find out if it's a Gen 1 issue too. Volunteers?

RECALL!!!!!!!!

Geezer · Nov 16, 2011

I am not going down to the garage to try that, not even in February with a couple feet of snow on the ground. :huh:

dcarver · Nov 21, 2011

wfooshee said:
At 1500 RPM in first there is such a small throttle opening that the difference between driving the rear wheel or not is enough to change the engine speed. Changing the load without changing the throttle results in an RPM change every time. Always.

I'm also assuming that by "disengage the clutch" you mean release the lever, which actually engages the clutch, as in causes it to transmit torque to the transmission. We don't see the clutch lever, we just see the tach and hear the motor. if you actually mean disengage the clutch by pulling the lever, then my explanation goes out the window:

Engaging the clutch, placing load on the engine, raised the rpm - that's what I found *unusual*. Disengaging the clutch resulted in lower rpm - opposite of what seems logical, where logic would say loading a throttle locked engine should drag engine rpm down.

CAJW said:
DJB said:

I guess the real question is why do we care? If the bike is doing it's job who cares how they programmed the ECU? You need to find more relevant things to rant about.

Click to expand...

rant/rant/

Verb:Speak or shout at length in a wild, impassioned way.

Noun:A spell of ranting; a tirade.

rel·e·vant/ˈreləvənt/

Adjective:Closely connected or appropriate to the matter at hand.

Synonymsertinent - appropriate

ob·ser·va·tion/ˌäbzərˈvāSHən/

Noun:

The action or process of observing something or someone carefully or in order to gain information.

The ability to notice significant details.

I would offer our good DC here is merely offering an observation, not a rant. He has always been a keen observer.

(or maybe a little weird, but aren't we all?)

Thanks CAJW!

Not a rant, just found the behavior unusual, like most of the inmates on this board!

HotRodZilla said:
Um...Carver is a LOT weird. How the hell does one even know this happens? You have snow at your house Don???

Geesh, not yet, but the dirt road is a mud bath.. Now then, where's the phone number for that female mud wrestling troupe?

BikerGeek99 said:
Don - are you high?

Is it Friday yet??

Yes, high on life!

Fred W said:
dcarver said:

Towards video end, you can see the speedo too.

Click to expand...

Yes you can. Is this an early April fools joke? The speedo is only dropping from 25mph to 15mph when the engine speed drops. This kind of suggests that the clutch is not actually being disengaged. :huh:

No Aprils fools joke - try it yourself, trust me! :rofl: You will be amazed with what you find out, causing you to research the ends of all technology to reach a reasonable hypothesis...

Spud said:
This should immediately be reported to the NHTSA. Under certain circumstances, this problem would lead to serious injury or death. Let's get a campaign started--I'll run home at lunch and see if mine does it too. We need to find out if it's a Gen 1 issue too. Volunteers?

RECALL!!!!!!!!

Exactly! This is world crisis!

beemerdons · Nov 21, 2011

So Carver, is the Creston harvest of the Fall mota crop finally completed and stacked in the barn, so you can now concentrate on other important and pressing matters.? That SLO Wowee must be killah, two hits and the paper turns brown!

dcarver · Nov 22, 2011

beemerdons said:
So Carver, is the Creston harvest of the Fall mota crop finally completed and stacked in the barn, so you can now concentrate on other important and pressing matters.? That SLO Wowee must be killah, two hits and the paper turns brown!

Come on BD, give it at try and say I'm wrong!

I freakin' DARE you!

This issue is huge, and will motivate earth from planned orbit unless root cause problem is identified!

So put Lucy on center stand, start, drop in gear with throttle locked at 1,500, then engage/dis-engage clutch...

double dog dare!

SaharaJp99 · Nov 23, 2011

Maybe the resistance of the oil when the clutch is opened up, ie disengage, is enough to bog down the engine just a tad. Once you engage the clutch it pushes the oil out from between the plates and is solid, with less surface area spinning through the oil. Once the clutch is engaged and the rear wheel spinning, I think the centrifical force of the rear wheel would keep the rpms up without the tire touching the ground with no "real" load, and the load of the oil would be more than that of a spinning wheel.

Just a thought and I'm probably way wrong and definitely not an engineer.

wfooshee · Nov 23, 2011

Yeah, oil is so much harder to move than gears and wheels and stuff.

Still haven't performed the experiment, but when I do, I will do it with the bike cold, and then warmed up, and see if either exhibits the Behavior, and if there's a difference.

Science, y'know.

SaharaJp99 · Nov 23, 2011

I sense the sarcasm.

You'd be suprised what kind of a load oil can add to an engine. Right now, John Deere has a recall out to replace all of the hydraulic and engine oils in their new skid steer line that are operated in sub-freezing temps. They are switching to a wider range viscosity fully synthetic oil. Why? Because with normal dyno oil in there it puts enough drag on the engine and hydraulic pumps that the starter can't spin the motor fast enough for it to start. Now I'm sure if oil didn't make a difference Deere would love to save the 100's of thousands that this is costing them.

FJRBluesman · Nov 23, 2011

Ok, a couple observations:

1) I concur, dcarver is weird...er than most.

2) Towards the end of the vid, the speed-O was also increasing/decreasing. So that would tell me your mileage will also suffer. Just sayin'.

3) This is definitely a Gen2 issue.

:huh:

RPM's increase when clutch is engaged

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