Author Topic: Rough take off and rough ride  (Read 8230 times)

XavierTico

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Rough take off and rough ride
« on: December 14, 2009, 08:57:55 PM »
I'm a new owner of a 2006 500. I don't know how many miles are on it because the speedo and odo don't work. The bike is immaculate, however, and the original tires on it don't look like they have rolled more than 1000 miles.

I've just moved up from a 125cc Honda scooter and I've got questions about two things.

First, when starting slowly from a stop or accelerating from a slow roll the bike gets into a sympathetic vibration with the engine at around 2500 rpm that feels like it's going to shake the machine to pieces. To avoid it I have to rev up quickly, (sometimes more quickly than I want to), or not slow down as much as I'd like to. The vibration is major, shaking the bike till the windshield and cargo box rattle. Any ideas to fix the problem? Different belt weights, perhaps, or a lighter or heavier slider?  I can avoid it completely by accelerating briskly from a stop. In that case the engine revs to above 3000 and feels like I'm slipping the clutch on a regular transmission, then drops into gear with a noticeable thunk and really digs in when the slipping stops. By the time it thunks in solid , the engine is reved above the critical 2500 vibe range, so I avoid the vibration. Is this normal?

The other item is the ride. I live in Costa Rica where many secondary roads and local streets are less than perfectly smooth. One of the reasons I moved up to the 500 was to have a heavier bike with bigger wheels to smooth out the ride. Much to my disappointment, my 125 has a noticeably smoother ride at low to medium speeds than this 500 does. Is there some adjustment I can make to take the jolt out of it? Can I soften the tires a bit without sacrificing handling?

Otherwise, I love the bike. Solid as a drilling platform on smooth four lanes, good power and wind protection, but the rough ride and the engine vibe are annoying a lot of the fun out of my new ride.

zombie

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Re: Rough take off and rough ride
« Reply #1 on: December 15, 2009, 12:56:10 AM »
Sympathetic vibration is ALWAYS caused by something /loose, out of round, or worn beyond service limits. Your scoot may have been ridden at specific rpm's since new , and taken a "set" where it will only run smooth if you repeat what was set into it. That being said, try getting the rear wheel off the ground, and revving the engine SLOWLY to get the symptom to occur. You can then try to isolate where it is coming from. Could be in the cvt or a rear wheel bearing or a loose engine mount. You will have to try to pinpoint where the vibration is originating to find the problem. Common sense will guide you through locating it. Since it happens riding it will happen on a stand as well. As for the harsh ride, tires, and air pressure go hand in hand. The Chen Shin tires that are most likely what you have are good all around tires, and cannot be run softer. (less air). Your two troubles MAY be related. A seized shock or fork? Kymco does have the tightest suspension of ANY motorbike I have ever come across, so once you find the first problem, you may want to "tune" the second.  Put it on blocks, and try to find the culprit! Maybe a mechanically inclined buddy can come over to hold the throttle while you poke around can help. Good luck, and please keep posting. Someone here may have the exact answer with more diagnosing on your end!
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

XavierTico

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Re: Rough take off and rough ride
« Reply #2 on: December 15, 2009, 02:28:49 AM »
Thanks. I was hoping some expert would tell me not to worry about it, they all vibrate like that. It's extremely smooth otherwise.

I'll get it on the stand soon and try to pinpoint the problem.

As to the ride, I think one of the rear shocks may not be working correctly. There's some oily crud on the innermost chromed cylinder, and some rust on the inside of the spring. It doesn't seem to compress properly when I have someone hop up and down on the back seat.  The tires are Kendas inflated to the pressures recommended in the manual.

Thanks again. I'll post what I find out.

zombie

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Re: Rough take off and rough ride
« Reply #3 on: December 15, 2009, 09:09:43 AM »
No Expert here; only trying to help w/ experience!  You will find the problem if you take it one step at a time. Just look for the "base" of the vibration. I have a thing against "dealer" trouble shooting. I have worked for other people, and know what it means to turn a $. You know what is happening w/ your scoot, so locate the trouble, and post the results to help another. The CURE is always in the last place you look.
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

jan.strydom

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Re: Rough take off and rough ride
« Reply #4 on: December 15, 2009, 01:39:16 PM »
I also believe that the clutch assembly is a possible culprit - your problem just sound a lot worse than the shudder or slipping noise problem I have - and all the dealer does is take the glazing off the clutch shoes and it goes away. It does sound that there is a possible shock problem as well and maybe the two together make it so bad!!

keep us posted

Jan

axy

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Re: Rough take off and rough ride
« Reply #5 on: December 15, 2009, 02:49:17 PM »
On scoots, this kind of shudder is in 99 % cases caused by flat spots on roller weights. You should be able to fix this for 15 U$ by buying new rws if that's the case.
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ts1

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Re: Rough take off and rough ride
« Reply #6 on: December 15, 2009, 04:39:17 PM »
At about 2500rpm the automatic clutch engages (or releases) and a worn or cold clutch may cause this effect too. I sometimes have this effect in the early morning.
And in fact the Xciting is not a very smooth starter. The (german) manual says you should not start slow.
If you have to drive slow with slipping clutch, it's easier coming from the high rev side and use the rear brake too.

XavierTico

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Re: Rough take off and rough ride
« Reply #7 on: December 15, 2009, 10:20:42 PM »
TS1, that is just the technique I've been using to avoid the rough spot.

I put the bike on the stand and ran it up some. There is a notable vibe when the transmission engages, but nothing like when it's got a load on it. Although the bike has no odo reading, I'm much more inclined to think this is an issue that resulted from the bike sitting unused than it is one stemming from heavy wear on some part or another. There are none of the obvious signs of wear that would show on a high mileage machine. Tires, brake pads, seat cover, floor mats, handle bar grips, brake handles, all show almost no signs of wear. The windshield has almost no scratches.

I just ordered a new set of rollers and I plan to examine the clutch when I get the cvt covers off. Unfortunately, the local dealer is little interested in maintenance work, and I have to order what I want in my less than perfect Spanish. He offered me an appointment to get the speedo fixed in early Feburary. I didn't even ask him about diagnosing the vibration problem.  It will take at least two weeks to get the new rollers from the States. Till then, I'm going to try to figure out how I'm going to get the variator and clutch bolts off without an impact wrench.

I appreciate everyone's input on this. I'll keep you posted.

ts1

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Re: Rough take off and rough ride
« Reply #8 on: December 16, 2009, 08:55:58 AM »
For the speedo/odometer look on the right side of the front wheel. Perhaps it is only the (too wide) gap between hall sensor and the spaced disc.
For the variator your mechanic should use special tools provided by Kymco.

axy

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Re: Rough take off and rough ride
« Reply #9 on: December 16, 2009, 10:13:30 AM »
TS1, that is just the technique I've been using to avoid the rough spot.

I put the bike on the stand and ran it up some. There is a notable vibe when the transmission engages, but nothing like when it's got a load on it. Although the bike has no odo reading, I'm much more inclined to think this is an issue that resulted from the bike sitting unused than it is one stemming from heavy wear on some part or another. There are none of the obvious signs of wear that would show on a high mileage machine. Tires, brake pads, seat cover, floor mats, handle bar grips, brake handles, all show almost no signs of wear. The windshield has almost no scratches.

I just ordered a new set of rollers and I plan to examine the clutch when I get the cvt covers off. Unfortunately, the local dealer is little interested in maintenance work, and I have to order what I want in my less than perfect Spanish. He offered me an appointment to get the speedo fixed in early Feburary. I didn't even ask him about diagnosing the vibration problem.  It will take at least two weeks to get the new rollers from the States. Till then, I'm going to try to figure out how I'm going to get the variator and clutch bolts off without an impact wrench.

I appreciate everyone's input on this. I'll keep you posted.

You do not need impact wrench to remove variator and clutch. To block the plate on the variator you can use custom tool that goes into two holes on it in order to fix it, you can use long thin pliers or something like that.
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Kymco Agility 125 2008

(Past: Kymco People 250S, Piaggio Beverly 200, Kawasaki ZR-7S, Yamaha TW125, Kymco Cobra Cross 50, Peugeot Zenith 50, Piaggio NRG 50 mc2 72 cc Naraku kit)

XavierTico

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Re: Rough take off and rough ride
« Reply #10 on: December 17, 2009, 03:05:25 PM »
Whether it's a custom tool that I don't have or an impact wrench that I don't have makes little difference. I'm scouring the local hardware stores now looking for something I can use. Good tools are hard to find in this country, and specialty tools damn near impossible.

In looking for the source of my vibration I've also discovered a little smile on the left side of the rear wheel rim. It looks like the careless use of a tire iron bent it out slightly. As a result there is a very small wobble in the rear wheel. I can't feel it at any speed, but watching the rim carefully as it turns makes it pretty obvious. Any ideas about whether such damage can be fixed or am I left with replacing the wheel?

zombie

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Re: Rough take off and rough ride
« Reply #11 on: December 17, 2009, 03:24:04 PM »
The wheels are cast aluminum, and they seem to bend fairly easily. The hard part is getting them back into shape. I have used a soft (brass) hammer to fix minor dings. 75% of the time it will work out fine.  25% of the time the piece will break off. If it is a smooth bend with NO kinking or apparent tearing chances are better for a repair. I would recommend releasing the air pressure before trying to fix it. You can also "make" the tool for removing your cvt parts with a piece of 1" steel stock 1/4" thick, and 10-12" long. drill two holes for 3/8" bolts that will act to capture the clutch, or multivar. If your clutch bell has a smooth surface (no holes in it) you can use a "strap" wrench similar to a large oil filter wrench. That can also be rigged up fairly easy with an old piece of garden hose on a 6"x1/2" drive extension. Where there is a will there is a way
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

axy

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Re: Rough take off and rough ride
« Reply #12 on: December 17, 2009, 03:32:39 PM »
The wheels are cast aluminum, and they seem to bend fairly easily. The hard part is getting them back into shape. I have used a soft (brass) hammer to fix minor dings. 75% of the time it will work out fine.  25% of the time the piece will break off. If it is a smooth bend with NO kinking or apparent tearing chances are better for a repair. I would recommend releasing the air pressure before trying to fix it. You can also "make" the tool for removing your cvt parts with a piece of 1" steel stock 1/4" thick, and 10-12" long. drill two holes for 3/8" bolts that will act to capture the clutch, or multivar. If your clutch bell has a smooth surface (no holes in it) you can use a "strap" wrench similar to a large oil filter wrench. That can also be rigged up fairly easy with an old piece of garden hose on a 6"x1/2" drive extension. Where there is a will there is a way

I have a slighltly bent rear brake lever for Agility 125 - my gf fell off it on oil patch on the road and this was the only damage, we bought a new one.

What do you think, would it be possible to straighten it using a rubber hammer or something? Or should I just leave it as it is as a replacement part in case the scoot falls again so I have to use something as "immediate" replacement?

Tnx.
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Kymco Agility 125 2008

(Past: Kymco People 250S, Piaggio Beverly 200, Kawasaki ZR-7S, Yamaha TW125, Kymco Cobra Cross 50, Peugeot Zenith 50, Piaggio NRG 50 mc2 72 cc Naraku kit)

drifter

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Re: Rough take off and rough ride
« Reply #13 on: December 18, 2009, 12:30:16 AM »
try cleaning you're clutch or better yet drill holes on you're clutch bell and modifiying the clutch linning.
"it's more fun to ride a slow bike fast than to ride a fast bike slow!"

zombie

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Re: Rough take off and rough ride
« Reply #14 on: December 18, 2009, 12:56:21 AM »
YES!  DO BOTH OF THE PRIOR POSTS! The handles that break, I use for "shorty's" use a grinder to clean up the broken edge and get yourself a set of shorty leavers (after a left,AND right fall) for FREEE
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

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