Acceptable Level of Vibs

weehe

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I'm trying to figure out if I am trying to fix something that just can't get any better on my 04. Currently at 6k rpms and up I am getting what I would consider unreasonably high levels or handlebar and seat vibes (I can live with the seat vibs). At 9k the stock mirrors are useless since they are shaking so much. Gets worse as you go to redline. Cruising at 70-80mph will make my hands go numb after 15-20min. This has been the only bike I've owned so I can't compare to anything else. Don't have any local friends that ride to try their bike. Only thing to note is an out of town friend with an 07 fz6 said he didn't notice and excess vibs, but I don't know how aggressive he rode it.

I have changed plugs, new air filter, new oil, ran freering in 2 tanks of gas, 5° trigger wheel mod, +1 on front sprocket (I think, which ever makes the gears taller), checked the plug wires, synced TBs at idle and 6k rpms, added grip puppies and weighted bar ends. The only thing I have not done yet is check valve gap. The bike has 42k miles on it, I've only put 5k of those on it, but is running great (besides the vibs). No history to know if it has ever been done. This is the only issue I have with the bike so I'm really hoping to fix it.
 

MattR302

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Do a throttle body sync, along with this:
 

Ohendo

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OP stated they did do the sync, and checked the plug wires. But not sure how you ‘checked’ them... so following above link is a good start.

It’s probably motor related... but check wheel balance too just to rule it out.

I have an ‘05, and haven’t had any issues with vibrations, so something is off.
 

weehe

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That link is what I meant by checking the plug wires. Wheels were balanced with new tires about 1k miles ago, no change. Could valve clearance really cause vibs? Was hoping there might be other low hanging fruit to try.
 

TownsendsFJR1300

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A tight gap in the valves is not good. If little gap /no gap when hot, besides burning a valve, the engine won't run correctly (one or more cylinders not fully sealing)

As you don't know(or didn't state) if the valves were checked, and your coming up on the SECOND RECOMMENDED mileage to check (every 26,600 miles), I'll pull the valve cover and do some checking.

Also, re-syncing at 6,000 RPM's should be done at 4,000 RPM's max. After 4k, the syncing doesn't matter/do anything.

How far out or close is the sync (in MM's) once done?

While doing a valve check, I would do a LEAK DOWN TEST as well as a compression test to check on the internals of the engine itself...

.
 

weehe

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A tight gap in the valves is not good. If little gap /no gap when hot, besides burning a valve, the engine won't run correctly (one or more cylinders not fully sealing)

As you don't know(or didn't state) if the valves were checked, and your coming up on the SECOND RECOMMENDED mileage to check (every 26,600 miles), I'll pull the valve cover and do some checking.

Also, re-syncing at 6,000 RPM's should be done at 4,000 RPM's max. After 4k, the syncing doesn't matter/do anything.

How far out or close is the sync (in MM's) once done?

While doing a valve check, I would do a LEAK DOWN TEST as well as a compression test to check on the internals of the engine itself...

.
Why would it not matter to sync above 4k rpms? I did 6k because it is closer to where I'll be on the highway. I do plan on checking the valves, just wasn't sure if there was anything else to look into. FWIW I pulled the header and the tops of the valves all looked good/uniform. Can't remember exact mm from the last sync, but they were almost spot on. I'll look into getting the leak down/compression test tools, but have no indications of a piston/ring issue.
 

TownsendsFJR1300

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The block, where you adjust the TB's works ONLY up to 4k. The factory manual only has you adjust at idle (no mention of 4k, etc). I've personally found a re-sync at 4K helped a BUNCH for vibs...

Anything after that, (4,000 RPMs) the butterflys are open, and syncing beyond that doesn't do anything..

Looking thru the head at valve stems does not show/tell how well the valve is sealing. You may see excessive carbon build up on the stem(indicating a valve seal leak-sucking oil into there, major carbon build up) but that's about it...

If you have a cylinder not performing properly/fully (low compression/leaky valves, worn rings, etc), the engines going to run rough...
 

weehe

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I'm not following you on the "butterflies are open". Are you saying the TB doesn't open until after 4k rpms? I'll give 4k a try and see if anything changes. The engine is definitely not running rough. It is very smooth in power delivery, and the power is just fine at the top end, no looping idle or bogging. My only thought on the valves possibly causing it is because it would be amplified at higher rpms.
 

TownsendsFJR1300

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I'm not following you on the "butterflies are open". Are you saying the TB doesn't open until after 4k rpms? I'll give 4k a try and see if anything changes. The engine is definitely not running rough. It is very smooth in power delivery, and the power is just fine at the top end, no looping idle or bogging. My only thought on the valves possibly causing it is because it would be amplified at higher rpms.

I didn't say that at all...
The throttle shaft/butterflys open when you turn the throttle.

The sync is performed under the tank at the circled (in blue) part below:




The base cylinder is #1, the rest are synced to that.

YAMAHA calls for no more than 10MMS difference at IDLE. That block, circled in blue, the adjustments work for ONLY UP TO 4,000 RPMS, period... Sync at 10k, 6k, it won't make a difference...

**Once past about 4,000RPMs, the throttle body butterflys (round plates attached the main throttle shaft-see below pic) control, if you would, the AIR FLOW as their open WAY MORE than at idle (or at 4k).

I doubt the sync is your issue but I would cover BASICS first.

Knowing the internals to the engines health is ESSENTIAL.. We don't know if the valves have been checked or are in spec...


Capture.JPG.
 

weehe

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I checked tb sync and they were within 4mm of each other at idle and 4k rpms. Got them to within 2mm but no noticable difference. Will check valves hopefully in the next few weeks.
 

pmmcanon

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Which vacum-meter are you using? Does it show the vacum value? As an example the Carbtune does it with more or less accuracy. Knowing the #1 cylinder vacuum value can tell you if the sync can be done properly using the #1 as reference.
 

pmmcanon

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I have the carb tune, all cylinders were at 22cm at idle.
Curious! This value seems to be 1 cm/HG higher than the recomended which, by the way, is very dificult to reach. 21 cm/Hg is the theoretical vacuum value at the sea level.
This means that your engine is leaks free but (also theoretically) at low rpm is getting less air than the expected; this doesn't mean a failure is just an adjustment and should affect only between iddle and 4k rpms. Do you have the iddle screw working properly or feel it hasn't a direct response to move it?.
Another point to check is the throttle buterflys sync. Do all of them move sync?
KR
 

weehe

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Wouldn't a higher vacuum mean it's getting more air at idle. It's sucking in more air. When going to 4k rpms the values were higher. Idle screw works just fine. Can move 900-2100rpms if I want, have it sitting right at 1260-1300. Last time I had the air box off there was no visual issue with the actual butterfly valves. All moved together.

On the valve check topic, I would assume if they are out of spec they would be out on the high side (too large a gap). Not sure how you can wear things out and the gap would get smaller. So if there is an issue it could be that the valves are not opening all the way.
 

TownsendsFJR1300

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Wouldn't a higher vacuum mean it's getting more air at idle. It's sucking in more air. When going to 4k rpms the values were higher. Idle screw works just fine. Can move 900-2100rpms if I want, have it sitting right at 1260-1300. Last time I had the air box off there was no visual issue with the actual butterfly valves. All moved together.

On the valve check topic, I would assume if they are out of spec they would be out on the high side (too large a gap). Not sure how you can wear things out and the gap would get smaller. So if there is an issue it could be that the valves are not opening all the way.

Valves tend to tighten up spec's with mileage/time .

Too tight a valve, especially the exhaust, can burn up a valve (as heat generated is not dissipated when the valve fully sits on it's seat)...

Exhaust spec's are wider due to the ex valve getting hotter, expanding and tightening up clearances more so than the intake valves.
 

weehe

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You would have more experience, I just don't understand how metal in the valve train can increase in size to cause a tighter gap. I figured metal would compress/wear out over time and cause a larger gap and lower lift.
 

TownsendsFJR1300

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You would have more experience, I just don't understand how metal in the valve train can increase in size to cause a tighter gap. I figured metal would compress/wear out over time and cause a larger gap and lower lift.

The valve tends to go deeper in the head as the valve seat (very hard steel seat) gets "hammered"/pressed (probably not the correct words) actually DEEPER into the aluminum head.

The valve goes deeper into the head (we're talking very small #'s now, .001" , etc) and the valve clearance tightens up (as the cam doesn't go anywhere).

Hydraulic lifters(most automotive applications), take up the slack with oil pressure in the valve train.

The shim and bucket style (what we have), is the best for high RPM engines as the shims are tucked underneath hardened "buckets"....

Lower performance engines (not high revver'), can use the hydraulic lifter (no adjusting) or the "set screw and lock nut" for adjusting the valve clearance. Those tend to not be as stable (clearances don't hold up under high stresses, high RPM's, etc).

In any event, the better the seal (no leakage via worn rings, worn valves, too tight a valve, etc) the better..

.
 

TownsendsFJR1300

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Please post back what spec's yours are once into the top end...

When I did mine at 26,600 miles I had one exhaust valve that out of spec's by .001"-
Now, pull the cam, chain, etc for .001"?? (#4 exhaust too tight).

I already had a shim kit and heck, that's why they have spec's. Out she came. Took a bit longer
but I know she's good for another 26,600 miles.

Yours, not knowing if it's ever been done, ever, is a definite "at least check it"

BTW, most first checks (from reading here the last 10 years), don't need adjustment. A few have been loose as well..



From 1-6-19, my exhaust cam pulled for adjustment:










Lastly, should you pull both cams, mixing them up is EASY. There is a way to tell the difference (I forgot but do a search here if need be)...


.
 

TownsendsFJR1300

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I thought about your post while out on a ride today and wound mine up to 12,000 in second gear.,
mirrors were just as clear as at 4k (it's rare i wind it up over 6K).

Anywho, something else to check for the vibs:
- Crack loose and re-torque ALL engine to frame mounting bolts(one at a time, should be 40lbs).
-Check head to header nuts, that all are tight.
-Check rear sub frame to main frame engine mount torques.
-crack loose ALL the exhaust clamps(leave the head to header alone). You want it just slightly loose so it can find it's "happy spot", IE, a pipe putting un-due(and vibs) thru the exhaust system, then being transferred to the rest of the bike. Then tighten the exhaust back up.
-If a faired bike, check the tightness of the fairing main stay to the frame itself for tightness..
 
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