Author Topic: Vibration at high RPM/SPEED  (Read 3793 times)

Pavel_proo

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Vibration at high RPM/SPEED
« on: March 12, 2021, 11:12:03 PM »
Hello everyone, I was lucky enough to get my hands on a 2009 250ri. With super low mileage. It pretty much didn't move until I purchased it. Upon purchase I have immediately noticed that the bike vibrates(mostly feels at floorboards) at rpms higher than 6500 and at speeds above 62mph or so. I have already replaced both original tires and balance wheels, not much difference. I have went further and replace the belt, what improved things slightly, but not enough. I have already checked valve clearances and adjust properly. Any suggestions as to where else to look?
Otherwise the scooter seems to drive just fine with good acceleration, etc.
« Last Edit: March 12, 2021, 11:34:38 PM by Pavel_proo »

JJJoseph

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Re: Vibration at high RPM/SPEED
« Reply #1 on: March 14, 2021, 05:51:57 AM »
Helkp us out: what is a "250ri"??

Kansas kymco

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Re: Vibration at high RPM/SPEED
« Reply #2 on: March 14, 2021, 03:36:47 PM »
I know your getting close to red line on the tach so I could see a little added vibration.   I had a vibration on my 09 250 RI above 55mph but mine was a front wheel out of balance. Previous owner had new City Grip's installed and balanced but the front tire was off balance.
In parts 200S and Grand Vista and my motorcycles 2 CS BMW'S and one GS BMW.

Sold-32 Kymco scooters of various sizes this summer.

Stig / Major Tom

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Re: Vibration at high RPM/SPEED
« Reply #3 on: March 14, 2021, 03:38:15 PM »
Helkp us out: what is a "250ri"??



Stig
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Neil955i

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Re: Vibration at high RPM/SPEED
« Reply #4 on: March 15, 2021, 10:36:27 AM »
Define "super low mileage"?  If less than 3K miles, I'd say wait until it's done a few more before looking to fix any "problem".  I had similar with my X-Town 300i from new and this all but disappeared at about 3,000 miles.  I put it down to full smoothness (if a single-pot bike can ever be classed as "smooth") not being reached until the scooter is properly broken in?
Regards & ride safe,
Neil

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Past bikes: BSA C15. Honda S/wing (GL500). Kawasaki GPz750. BMW K100RS. Kawasaki GPZ900R. Yamaha FJ1200 x2. Sprint. Triumph Daytona 900. Kawasaki ZX-7R. T595 Daytona. Kawasaki ZX-9R x2. Triumph Daytona 955i. X-Town

CROSSBOLT

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Re: Vibration at high RPM/SPEED
« Reply #5 on: March 15, 2021, 02:24:21 PM »
Vibration in sync with road speed or engine speed?
Karl

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Neil955i

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Re: Vibration at high RPM/SPEED
« Reply #6 on: March 16, 2021, 09:46:50 AM »
Vibration in sync with road speed or engine speed?

I'm guessing it will be engine speed (mine was) rather than an unbalanced wheel?
Regards & ride safe,
Neil

Current garage:  Kymco DTX360 & Triumph Street Triple 675R
Past bikes: BSA C15. Honda S/wing (GL500). Kawasaki GPz750. BMW K100RS. Kawasaki GPZ900R. Yamaha FJ1200 x2. Sprint. Triumph Daytona 900. Kawasaki ZX-7R. T595 Daytona. Kawasaki ZX-9R x2. Triumph Daytona 955i. X-Town

Pavel_proo

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Re: Vibration at high RPM/SPEED
« Reply #7 on: March 19, 2021, 06:32:15 PM »
It seems to be more engine speed related.
I am still not sure where to look.

Pavel_proo

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Re: Vibration at high RPM/SPEED
« Reply #8 on: March 19, 2021, 06:33:14 PM »
Define "super low mileage"?  If less than 3K miles, I'd say wait until it's done a few more before looking to fix any "problem".  I had similar with my X-Town 300i from new and this all but disappeared at about 3,000 miles.  I put it down to full smoothness (if a single-pot bike can ever be classed as "smooth") not being reached until the scooter is properly broken in?
280 miles at time of purchase 8)
1500 now

CROSSBOLT

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Re: Vibration at high RPM/SPEED
« Reply #9 on: March 19, 2021, 09:41:00 PM »
I'm guessing it will be engine speed (mine was) rather than an unbalanced wheel?
Engine speed, may have a stuck or damaged roller in the variator..
Karl

Three motorcycles 1960-1977 (restored a 1955 BSA)
Agility 50
Yager 200i
Downtown 300i
Navy tech, Ships Engineer, pilot and aircraft mechanic

Pavel_proo

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Re: Vibration at high RPM/SPEED
« Reply #10 on: March 20, 2021, 01:56:30 AM »
Engine speed, may have a stuck or damaged roller in the variator..
I got Tech Pulley Flying Roller II sliders installed today. Will report tomorrow as to how that worked out.
By the way Tech Pulley is supposedly a next gen of Dr. Pulley and claims to be even better preforming.
« Last Edit: March 20, 2021, 01:58:59 AM by Pavel_proo »

Pavel_proo

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Re: Vibration at high RPM/SPEED
« Reply #11 on: March 26, 2021, 08:03:58 PM »
Sorry for no updates. Bike doesn't start. Will update once fixed.

Pavel_proo

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Re: Vibration at high RPM/SPEED
« Reply #12 on: April 02, 2021, 02:00:35 AM »
So, got the bike fixed all good now.
However as for vibration it seems perfectly smooth up to about 65 mph when vibration starts and gets gradually worse with 70+ being uncomfortable quite a bit. With new sliders the cruising rpm went down so that's probably why the vibration now starts at a higher speed. So it is definitely engine speed related and not ground speed related.

Kansas kymco

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Re: Vibration at high RPM/SPEED
« Reply #13 on: April 02, 2021, 02:18:03 AM »
So, got the bike fixed all good now.
However as for vibration it seems perfectly smooth up to about 65 mph when vibration starts and gets gradually worse with 70+ being uncomfortable quite a bit. With new sliders the cruising rpm went down so that's probably why the vibration now starts at a higher speed. So it is definitely engine speed related and not ground speed related.
65 mph on mine is red line. What's red line now with the new sliders?
« Last Edit: April 02, 2021, 02:20:58 AM by Kansas kymco »
In parts 200S and Grand Vista and my motorcycles 2 CS BMW'S and one GS BMW.

Sold-32 Kymco scooters of various sizes this summer.

Pavel_proo

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Re: Vibration at high RPM/SPEED
« Reply #14 on: April 02, 2021, 01:32:35 PM »
65 mph on mine is red line. What's red line now with the new sliders?
I tried pushing it to 80mph(8000+ rpm) yesterday two up and it did fine except for engine vibration.
Right now 65mph is just slightly over 6500rpm. 23g tech pulley flying roller II sliders and malossi belt.
I am actually starting to think that what I describe as a vibration is really a normal motor vibration for a a 1 cylinder.
« Last Edit: April 02, 2021, 11:13:55 PM by Pavel_proo »

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