Author Topic: More low frequency vibes after break in?  (Read 5774 times)

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Ducati Scotty

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on: September 02, 2010, 08:00:00 pm
I've noticed a change in my bike in the last 1500 miles or so, wondering if it's normal.  It feels more rumbly with some low frequency vibes that weren't there.

When new the engine was a little harsh and vibey as they all are.  If you pushed it much into the higher revs it would shake a lot and complain, low and high frequency vibes.  It did NOT want to rev that high.  Easy enough, just don't rev high and all was well.

By around 1800 miles the engine was much smoother and smooth all the way up to 75mph.  Most of my riding is between 40 and 60 but I took it faster a few times, up to 75 a few times, 80 once.

Now at 3400 it seems different.  It starts easily and runs fine but it seems less smooth.  At idle it seems like there are more low frequency vibes, same just off idle while riding.  Nothing terrible.  It runs fine at regular speeds, maybe a little more rumbly, pretty smooth up to 60mph.  65 gets a little low frequency vibe going, moreso at 70.  It's not like when it was new and didn't want to rev and felt bad if you pushed it.  It will go but just vibrates more than it did 1500 miles ago.  The high frequency stuff is gone and the engine feels looser and more rumbly in general.

I'm planning to loosen all the engine mounts, have someone sit on the bike, and retorque them.  It's an old trick used on a lot of British bikes to relieve any pent up tension in the frame and quiet resonance.

Bradey noted something similar in another thread.  Is this just what a broken in engine feels like?

Scott


ScooterBob

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Reply #1 on: September 02, 2010, 08:45:11 pm
Scotty - Those bikes seem to change dramatically to the "tuned in" ear with break in. Your idea to "de-stress" everything is a good one. If you do it just right, it'll make all the difference in the world to you - you OBVIOUSLY have a sensitive "butt-dyno" -  ;)

The bike that I have been running the snot out of seems to get smoother and smoother with each passing flog ..... it's very impressive with its lack of harsh vibrations - although it seems to have the "mystery tick" that comes and goes completely at random. It's "OFF" today .... but day after tomorrow it'll sound like an Iron Barrel for the first run .... Go figger!
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Ducati Scotty

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Reply #2 on: September 02, 2010, 09:17:12 pm
Bob, how many miles on your dedicated flog machine?

Scott


ScooterBob

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Reply #3 on: September 03, 2010, 01:46:24 am
Bob, how many miles on your dedicated flog machine?

Scott

It has about 675 miles and one eight foot vertical on the chassis - nearly double that on the mill ...... That would be the equivalent of about 10K "normal" miles, I think .....  I was noticing today that there is close to a hole ground in the brake pedal rod and the sidestand and centerstand edges are getting ground off pretty nicely. Me and the Tall Skinny Kid have a gentleman's bet on WHEN I'm going to wad it up ...... Hahaha! That heep has led a race bikes life ..... and seems to take it FAR better than anyone ever thought it would, I'm wholly impressed with it in every way ........ really!
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Ducati Scotty

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Reply #4 on: September 03, 2010, 05:03:19 am
I stopped by the dealer today.  Justin and Pedro both took it out for a run up to high speed.  Definitely feels different but nothing seems out of place.  They both said it actually feels quite good.  i guess it's just the way this one is breaking in.  I'm still going to loosen an retorque the motor mounts, can't hurt ;)

How many miles does an 8' vertical drop equate to anyway? :P

Scott


BRADEY

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Reply #5 on: September 03, 2010, 11:28:47 am
Scotty, I have felt exactly what you have observed on your bike. Although mine was a little different. It some how vibrated more on speeds just a little above idle when new, but everything ironed out above that. It never felt stressed even if I revved it.

After 1600 miles the bike ran like a Honda CB750 smooth as it could be, two up, at 75 MPH with only a tingle at the handle bar. It would top out at 90 MPH indicated on the Speedo.

But now things have changed for worse. It vibrates like an Iron barrel anything above 65 MPH, and refuses to go beyond 70 MPH if I am sitting upright, though chin on tank it will still do 80 MPH, but feels strained all the way from 65-80 MPH.

Wondering what went wrong.................. :-[


ScooterBob

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Reply #6 on: September 03, 2010, 12:40:38 pm
Scotty, I have felt exactly what you have observed on your bike. Although mine was a little different. It some how vibrated more on speeds just a little above idle when new, but everything ironed out above that. It never felt stressed even if I revved it.

After 1600 miles the bike ran like a Honda CB750 smooth as it could be, two up, at 75 MPH with only a tingle at the handle bar. It would top out at 90 MPH indicated on the Speedo.

But now things have changed for worse. It vibrates like an Iron barrel anything above 65 MPH, and refuses to go beyond 70 MPH if I am sitting upright, though chin on tank it will still do 80 MPH, but feels strained all the way from 65-80 MPH.

Wondering what went wrong.................. :-[

Have you pulled the plug out of to check it yet? That's about the ONLY thing that could change - the EFI will "tune around" the rest! Also - beware that some parts of the world are now getting deliveries of "winter formula" gasoline - that'll change 'er up a bit, too .... I know we are getting some of it here because it smells different ....
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Ducati Scotty

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Reply #7 on: September 03, 2010, 02:26:21 pm
Bradey, that sounds worse than what I'm seeing.  My bike still runs ok it just feels different.

Bob, I did look at my plug not long ago, looked fine.

Scott


Maturin

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Reply #8 on: September 03, 2010, 10:58:06 pm
Actually EFIs vibrate different. I had the chance to take a ride on another G5 the other day, when I picked up the new fork springs. It was behaving totally different! At the tender age of 150 km the bike had an open fishtail muffler and loads of torque. But before I could turn green from envy I noticed hard vibes mainly in the footrest. O boy! 10 minutes later I came back with the pleasurable feeling of returning to my own, cultivated motorcycle  8), that moves basically straightforward.
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ScooterBob

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Reply #9 on: September 04, 2010, 12:36:45 am
Yeah - You can TELL the UCE has more verve by the "tune" she plays through the frame .... not harsh - but different to be sure. The old, comfy Iron Barrel has a totally different, agricultural, throb to it. As a BIG fan of old bikes of every kind - I find the dull thud of the Iron Barrel engine quite a comfort after a long day. The UCE is a lot like a Velocette Venom - it wants to urge you to go faster! The Iron Barrel urges me to relax and be calm .... and just get mesmerised by the "thump, thump, thump, thump" that it makes beneath me.
Spare the pig iron - spoil the part!


Ducati Scotty

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Reply #10 on: September 04, 2010, 12:59:44 am
If you hold an O2 sensor equipped model at a steady mid throttle cruise you can hear and feel the oscillation of it slipping back and forht from lean to rich as the EFI does its magic.  Personally I prefer FI, but I grew up on carburetors and I miss working on them.  I don't miss needing to work on them.

Scott


gashousegorilla

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Reply #11 on: September 04, 2010, 01:26:32 am
 Let me tell ya, with all this high speed testing going on. This little motor loves to run. And smooth when you all the way up there.
An thaibhsí atá rattling ag an doras agus tá sé an diabhal sa chathaoir.


ScooterBob

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Reply #12 on: September 04, 2010, 02:48:28 am
Let me tell ya, with all this high speed testing going on. This little motor loves to run. And smooth when you all the way up there.

I find it interesting that the harder I thrash the Crash Test Dummy - the BETTER it gets! It's plum NUTS, I tell ya! It SURE ain't no Iron Barrel! The boys in India hit the ball out of the PARK with THIS little mill ..... it's quite the worthy unit!  ;D
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singhg5

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Reply #13 on: September 04, 2010, 05:27:09 am
I find it interesting that the harder I thrash the Crash Test Dummy - the BETTER it gets! It's plum NUTS, I tell ya! It SURE ain't no Iron Barrel! The boys in India hit the ball out of the PARK with THIS little mill ..... it's quite the worthy unit!  ;D

These new UCE engines are miles ahead of the Iron barrel , AVL or ABCDZ whatever RE made before, unless you convert them into ACE Fireball  ;) 
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Reply #14 on: September 07, 2010, 10:26:33 pm
I am noticing some kind of irregularities in running as mr scotty reported. Also within the last 800-1000 kms there´s been more false neutrals in there 3-4-5 area (mentioned in another thread). About 8600 kms done. I thought things would get smoother with the travel done. After reading this thread I do believe some of the jerking is due to the ecu controlling fuel feed but there is some kind of mechanical grunt going on at 55 - 70 km/h. The rear chain is changed (D.I.D) and running well. My C5´s guarantee (parts and work) ended 4.9.-10, so a bit worried. some of you might recall that my c5 is running without auto-decompressor since what ... 6800 kms. Had that failure twice.