Another vibration thread...

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blue09

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Bought the 09 used last year, had around 4,000 miles on it. I guess I like it because I am at 24,000 miles now.

I had the common 5k-5.5K buzz right away, read all the fairing mod stuff and it fixed that. I would get a minor 6k buzz but it was really smooth from 7k to redline...like electric engine smooth, and it just loved to play up there.

Now I have very harsh vibrations from 5k all the way up. I am talking hand and feet tingling for awhile after getting off the bike and having spent some time in the high rpm range.

The bike- gutted cat and 2 brothers slip-on, fuel line mod, blocked AIS..that's it from stock.

The vibration started occurring about three weeks ago, but did not immediately start out as bad as it is now.

Occurs on the side side, on the center stand, and while riding in neutral or any gear.

Things I have tried:

All the fairing mods I could find on this site, felt around wires, instrument cluster, radiator guard, radiator covers, etc. Basically tried just about everything I could find. Absolutely zero change.

Changed the oil, spark plugs, air filter (plugs all looked great). Removed and re-torqued motor mount bolts, put a wrench on pretty much everything I could access to make sure they were tight.

Removed the slip-on, ran open header, no change. Put rubber tape on fairing bolts.

Ran several tanks of gas through from different locations. Used good injector cleaner in every tank.

I am down to a valve adjustment or who knows what else I can try. It really seems like it is just a rough engine above 5k and its no longer fun to ride. I also think I am down on HP at the high end, but that is my subjective butt dyno.

Not burning oil, and no other indications that there are other engine issues.

Thanks!
 
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Wow! That's a lot of troubleshooting and still not finding it... Sorry it's happening.

You could try to test all four coils. Some have been known to fail under load with micro fractures causing arc points.

Sync the throttle bodies.

Have you had the wheels balanced? Did you recently put on aluminum angled valve stems? I've heard of those causing vibrations if not balanced. One other quick though... take off all wheel weights and put dynabeads in both tires.

Wheel bearings and steering stem bearing are all tight?

That's all I can think of outside of your extensive list...
 
FZ1inNH said:
Wow! That's a lot of troubleshooting and still not finding it... Sorry it's happening.

You could try to test all four coils. Some have been known to fail under load with micro fractures causing arc points.

Sync the throttle bodies.

Have you had the wheels balanced? Did you recently put on aluminum angled valve stems? I've heard of those causing vibrations if not balanced. One other quick though... take off all wheel weights and put dynabeads in both tires.

Wheel bearings and steering stem bearing are all tight?

That's all I can think of outside of your extensive list...
Click to expand...

Coils and throttle bodies are both very good things to check as you suggested. Since it does it on the side and center stands we can rule out wheel balance and worn sprockets (or chain issues).
 
Oldschool said:
Coils and throttle bodies are both very good things to check as you suggested. Since it does it on the side and center stands we can rule out wheel balance and worn sprockets (or chain issues).
Click to expand...

Well there's my DUH moment... Skipped over the side and center stand facts. ;: :doh2:

Good catch Lee! :tup:
 
Correct, but in your case, because you haven't touched them yet, DON'T touch #2 or 3, just use the spring screw I mentioned to balance those two, then use the brass screws on #1 & #4 to balance them with 2 & 3.

I only had to seat the screws and back them out 2 turns BECAUSE I'd tried to adjust #2&3.... Your sync will be easier!
 
FZ1inNH said:
Correct, but in your case, because you haven't touched them yet, DON'T touch #2 or 3, just use the spring screw I mentioned to balance those two, then use the brass screws on #1 & #4 to balance them with 2 & 3.

I only had to seat the screws and back them out 2 turns BECAUSE I'd tried to adjust #2&3.... Your sync will be easier!
Click to expand...

Well the procedure went perfect! 1 and 4 were put all they way in and then out two turns. Got 2&3 matched with just the screw. Then I matched 1&4 to 2&3, they all lined up perfectly.

And now the really good news....I think it is fixed! Only went for a short 15 minute ride but it is smooth at the top and the harsh vibes are gone. I will do more testing tomorrow. I was actually very skeptical that the sync would work, since everything else I tried made zero difference. I wonder how they get out of whack anyway? I can't see what could possibly change over time in that area of the engine.

I guess maybe one thing I would add to the procedure- Hook up your gauge and have a look at all four before you touch anything! I seemed to have a big improvement, so I am curious what the readings were before touching a screw.

I am going to test the coils as well just for a sanity check.

Thanks guys!!
 
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That's awesome news! Yes, you should check with the gauge in place first just to see where all four are reading. But ,the key is getting them balanced which you accomplished. Well done!

I'm not entirely sure why these cause such vibration when they are not in sync. I think Ivan could tell us how it factors in. He also might have an explanation of how/why they change.

Still going to do the pictorial when I set up my wife's bike.
 
I used this DIY:

http://www.998cc.org/forum/gen-ii-tech/18874-throttle-body-sync-diy.html

And the pics in this thread from Erci...they were very helpful...

http://www.998cc.org/forum/gen-ii-tech/9607-throttle-body-sync-2.html

The brass screws are difficult to access. I used ty-wraps to pull wire bundles and hoses away to better access the screws while tuning. I also had to go buy an assortment of small screwdrivers for the job. The brass screw locations are not user friendly. Just be patient and keep at it until you find a way to access them that works for you.
 
Showing my noobness here. I thought for some reason you only had to sync carbs. I never realized you need to sync throttle bodies too. Anyone have a pic of the tool? Going to check my valve clearances and other stuff during to super long cold NH winter.
 
This is the one I have. If you don't want to spend the money to buy one, you're welcome to ride to Dover and I'll help you with it. :D

MORGAN-CARBTUNE.jpg
 
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