Pulsating engine speed?

[donkey rider]

One of the things I wanted to consult with people is the pulsating engine speed of my 2008 FJR. Here's what it sounds like:



It doesn't feel right.

In the vid the bike is cold, but it does the same when it's warm. I also think it might be what contributes to the jerking when I start moving.

Any ideas?

 

[RaYzerman19]

It's cold, it's leaned out in the FI department..... let it warm up to improve...... so what's next.... Barbarian mod, hot idle speed up to 1000-1100, unwind your throttle spring, live with it or get a PC-V. Lots of info on here about all. Pssst.... go with the PC-V.

 

[donkey rider]

It's cold, it's leaned out in the FI department.....

Ummm... It doesn't change when it warms up, only the idle RPMs drop, but still keeps pulsating. Sometimes it evens out, then starts pulsating again.

Not sure what "leaned out" means, sorry

Barbarian mod, hot idle speed up to 1000-1100, unwind your throttle spring, live with it or get a PC-V. Lots of info on here about all. Pssst.... go with the PC-V.

Yikes! From what I've read so far it seems that PowerCommander is a rather widely used thing... Is it really worth installing? Doesn't it void warranty?

 

[spyderbret]

Pssst.... go with the PC-V.

+1!!!!!

The Power Commander is a great addition. If you are patient they come up for sale in the classifieds on a pretty regular basis. That's how I got mine.....

Good luck!!

 

[03HiYoSilver]

donkey,

If you think it is that Bad, take it back to the Yamaha Authorized Dealer and have it checked out. At least start a repair ticket to document you perceived issue(s).

 

[donkey rider]

donkey,
If you think it is that Bad, take it back to the Yamaha Authorized Dealer and have it checked out. At least start a repair ticket to document you perceived issue(s).

Well, I've been to a dealer once, and they said everything's fine, so I wanted to check with others before I go there again insisting something is not right

 

[03HiYoSilver]

Donkey,

Contact your Regional Yamaha Service Manager and have them look at your problem personally or let them know about what is happening.

 

[blkredlinedrvr]

I dunno sounds fine to me. I've had a few 4-cylinder bikes and never had them idle "evenly". It doesn't affect the bike for me anyway and never caused a problem so I just ignore it.

 

[wheatonFJR]

Have the bike been synched?

 

[RaYzerman19]

+1 on what the guys are saying.... The system runs so lean (emissions requirements) some surging occurs. A throttle sync will help, and when you're at the dealer documenting your concern, ask them to do a throttle sync as it will help some.

 

[dhb820]

I have a new 2010 FJR and it does the same thing, but does not seem to have an effect on performance.

 

[donkey rider]

Mine does affect the ride as well - it's not just the idle, it's also doing that under low acceleration as well. If I give it a little more kick - it's not noticeable, but if I accelerate just a little bit, or coast - then the bike even starts to jerk a little bit. I'll ask the dealer to do the throttle sync... Thanks!

 

[kolonial72]

I don't see how a Power Commander would void the warranty. If you're concerned about that, it is a simple task to remove the PC prior to taking the bike in for service.

The symptoms you describe are fairly common. My '05 exhibited the same behavior. Down low it was a PITA, but with more throttle the thing would scream down the road. I performed two TB syncs and played with the Barbarian mod to no avail. The PC3 with Wally's smoothness map smoothed that bike out to just about perfect.

The low-end jerkiness is more than a nuisance as it can cause difficulty with low-end (parking lot) maneuvers. However you do it, you would be wise to fix such an issue, and not just for convenience.

 

[JamesK]

Honestly I couldn't really hear anything terribly wrong from that vid. However, as others have already said, your best bet to get the bike to run smoother and cooler is to ad a Power Commander. Than do the TBS after the PC is installed.

Now if you believe the bike is running even rougher than just being tuned too lean, you could check for vacuum leaks, as a small vacuum leak say in one of the TBS rubber caps or other hoses would certainly be more noticeable at lower RPMs.

 

[donkey rider]

I don't see how a Power Commander would void the warranty. If you're concerned about that, it is a simple task to remove the PC prior to taking the bike in for service.
The symptoms you describe are fairly common. My '05 exhibited the same behavior. Down low it was a PITA, but with more throttle the thing would scream down the road. I performed two TB syncs and played with the Barbarian mod to no avail. The PC3 with Wally's smoothness map smoothed that bike out to just about perfect.

The low-end jerkiness is more than a nuisance as it can cause difficulty with low-end (parking lot) maneuvers. However you do it, you would be wise to fix such an issue, and not just for convenience.

Agree on the low speed maneuvers: I can't do a u-turn without help with my foot as it's very unstable and hard to control. I'm definitely gonna give the PC a go!

Thanks all for your help!

P.S. I'm definitely going to have more questions once I get to that, so beware

 

[blkredlinedrvr]

Feathering the Clutch is your friend. You can keep engine speeds a bit higher without actually going faster. Also the final drive unit and transmission both have play in them, it's hard to keep constant power on the drive train without feathering the clutch to keep all the parts from "bouncing" around as they load and unload with engine power.

 

[Fred W]

The idle stumbling in your video is just the way that these bikes all run in stock form. If you listen closely to a lineup of FJRs you'll hear that they (mostly) "all do that".

It is caused by the mixture (intentionally) being a bit on the lean side, for emissions purposes. Even with a PCIII (and disconnected O2 sensor), unless you tweak your fuel map in the cells in the upper left corner of the map (at zero throttle and 1000-1250 rpm) it will continue to have that burble. I have actually tweaked those cells (along with others in that column) and have made my idle considerably smoother. That said, it really isn't a big problem and definitely not worth getting a PCIII just to get rid of that.

However, sensitive riders may also notice that the engine actually exhibits this same "lean stumble" whenever the engine's fuel injection goes into the closed loop mode while riding along. In addition to at idle, closed loop mode happens whenever cruising at a steady throttle setting and relatively light engine loads. The way it feels is like the bike's speed is "lurching" just a little bit, even on very smooth roads and with no winds. This was actually the phenomenon that prompted me to get a PCIII for my 1st gen.

The added bonus of having the PCIII (and disconnecting the O2 sensor) is that the ECU will never go into closed loop mode, and you can add fuel up and down the first few columns of the map where the 0% and 5% throttle openings are. You will never be cruising or riding around at these throttle settings. What they will effect is what happens when you close the throttle down as you come into a corner, and then want to roll back on the throttle mid-corner. The default ECU fuel map cuts off all fuel under trailing throttle situations, which makes the roll-on very herky jerky. Exactly what you don't want in mid corner. Adding fuel in these columns softens that transition and makes the bike much more ride-able.

Curiously, the maps that you get from DynoJet, and most of the other fuel maps that you see around, do not make any attempt at enrichening the zero throttle column of the fuel map, instead paying attention only to 5% and greater throttle openings where cruising and acceleration happens. However, if you do diddle with the first column, whether or not your bike would pass an emissions gas test is surely in doubt. These settings are for "offroad use" only

 

[cruppelt]

I have a 2006AE, mine sounds almost identical to yours in idle, warm or cold. I have done a TBS, new plugs and have a PC in there with a good map (custom dyno), and it's still doing it the same way.

The only thing I am wondering about that might still help would be bathing my gearbox clutch plates in oil (clutch soak) when I'm doing my next service. I've always wondered about the fact that it seems to idle better when in first gear in comparison to a rougher idle and grinding noise when in Neutral.

 

[donkey rider]

I think I kind of figured out a way to deal with the "jerkiness" when starting to move or moving at very low speeds by rolling on the throttle a bit more than usual and holding the foot brake, using the latter to "smooth out" the jerkiness. It works well for left turns, but not so well for tight right turns (in case I don't do it absolutely perfectly and have to use right foot to balance).

And there's also the question whether this has a negative effect on the clutch.