Vibrations @ 4200 Rpm

[NorthRider]

First of all, congrats on this new site, looks great and very quick!

I have presently 4000 km's on the blue FJR. Compared to my previous 03, I find this one has more vibration when idling around 4200 RPM. I have not done the throttle bodies synch yet. I got the carbtune II only last friday. Will be doing the synchronisation probably today.

While doing the synch, is it recomended to do this at idle or around 3500 RPM ?

Also once the throttle bodies are in synchronization with each other, will the addition of a power comander further reduce the 4200 RPM vibration?

So far I like the bike but this vibration is just annoying. I don't mind spending an extra 300 $ on a PC III if this will smoothen the FJR.

What are your experiences with this ?

 

[Yambone]

I've done about half dozen throttle body synchs so far with the Carbtune II, so by now it is an easy procedure to pop the gas tank open and go at it. Ride it around, if not happy, easy enough to go in again. I synch at idle and then rev to a steady state 4000 rpm and have gotten close enough synch at both. I can reduce and "move" that pesky vibration at 4200-RPM to about 4600-RPM, but can't totally get rid of it. I use foam grip covers over the stock heated grips. Widens my fingers and also reduces the vibes. I can ride all day and have no residual buzz in the hands, as we are talking about a very minor vibe problem.

The PC III has a 'smoothness' map, so those folks will chime in shortly, no doubt. I've stayed with the stock settings, as I usually get 44-mpg and nearly 50-mpg fuel economy in higher elevations, and don't wish to muck that up.

Enjoy the Carb Tune II and the world-o-Doityourself!

 

[Ignacio]

I agree playing with throttle body synch probably helps the most, but it obviously doesn't totally eliminate it. I think the addition of bigger bar end weights (Top Gun) helps a bit too. Then in my case the BMW grips helped just a little bit more.

Those three things I did in short order added up so I went from noticing it all the time to where I don't notice it anymore unless I'm concentrating or obsessing on it.

 

[escapefjrtist]

Recently did a TBS and plug change at 9000 miles. The #1 cylinder was slightly high about 11-12mm, the remaining three were as I set them at 5000 miles. These two items, for the most part, eliminated the 4200 rpm buzz. The bike is now very smooth running through the gears or on steady cruise. Also, seems like the engine has smoothed out between 7-9000 miles.

I have the top gun bar weights, didn't notice a significant improvement with them verses the OE ends..... my $.02

--G

 

[Constant Mesh]

The 4200 rpm buzz probably can't be adjusted out with a TB sync, etc. To verify this you can gradually increase revs in each gear as you accelerate up to cruising speed being careful to notice the engine vibes around 4200 rpm. The throttle opening corresponding to 4200 rpm in each gear will be considerably different. Yet, when you pass through 4200 rpm in each gear you'll notice an increase in engine vibration.

If the vibration was primarily a function of TB sync it would ebb and flow with throttle opening. But, the maximum buzz always seems to occur at around 4200 rpm.

Finally, butterfly valves such as those in the TB's are very imprecise flow control devices. They have a significant effect on air flow during their first few degrees of opening but once open more than 15 - 20 degrees or so they are very crude flow control valves.

Thus, trying to fine-tune them when they are almost totally closed may be desirable but trying to fine-tune them when they're open 20 degrees or more may offer little value.

 

[yamahlr]

I have to agree w/ escape, I installed the topgun weights. Other than looking the part, didn't seem to notice a difference with them verses stock.

 

[ionbeam]

Just a quick note that EPA numbers are taken around 4k rpm and engine intake/exhaust design is optimized for EPA and not for riding comfort in this range. Research will show that in all motorcycle groups there is a driveability, buzz issue around 4k rpm. We will hear from the few and lucky exceptions shortly.....

Alan

 

[NorthRider]

Well At least I'm not the only one with this problem.

I still comtemplating getting the Power Commander III, but only if it will improve / minimize the 4200 RPM vibration.

Would like to hear from those who have upgraded to a PC III. Is there much of a difference in the buzz/ vibration @ 4K RPM range? I'm not concerned about HP gains or anything, just stable engine from 1100 to 5000 RPM range. I'm mostly in the 4K range and this buzz is annoying. :angry:

 

[ionbeam]

My '04 has had a careful sync and I have a Power Commander III installed (without the Smoothness Map). SpeedFreak and I traded his '05 for my '04 for a short ride to see if my bike was any smoother than his. His opinion was that my synched, PCIIIed '04 was no smoother than his unmodified '05.

I am not bothered by what I perceive to be a very minor buzz. SpeedFreek seems to be annoyed/bothered by the buzz. Given the same situation we all draw different conclusions. Heck, if we all thought alike one of us wouldn't be necessary <_<

Alan

 

[gypsy]

I too have added the bar end weights from FJR Goodies but I also wear Olympia gloves which have gel in the palms. The combination pretty much takes car of any buzzing.

gypsy

 

[kerhrhr]

When did you all start to notice the vibration? Was it from day one, or did it start to settle in after the break in? Maybe I am one of the lucky ones, but I dont' feel any vibration on my 05. Of course I only have 500 miles on it right now. Only had it a week.....

 

[NorthRider]

I notice it the vibration past the 1000 Km. I may had it from the very beginning but I didn't bring up the RPM very high during the breaking. I now have 3700 Km's

I did the TBS yesterday. They were slightly off. Well go and ride today and report later

 

[Bearly Flying]

I recently sync'ed my throttle bodies on my 05, 5000 km on it. Adjusted the air bleeds at idle as per procedure and then balanced the TB's with each other at 4200 rpm. Had to run it up and down several times checking the top and bottom settings and idle speed each time. Made quite a difference in vibration levels at Hiway speeds. ( The bottom end was fairly close before I started, but the settings at 4200 rpm were out quite a bit with # 2 and 3 cylinders doing most of the work.) Don

 

[OrangevaleFJR]

You all have it wrong!!!

All you have to do is borrow my 1977 BMW R100RS for a few hours and you'll never complain about vibration again :lol:

 

[gr8eyes]

I synched the TB's and installed a PClll, and put in iridium plugs. It made a huge difference in the buzziness on my bike. I don't think the plugs had anything to do with it but the bike sure did run smooth after all that.

Glenn