Super 9 Vibration

[gordon_as]

Have wanted a scooter for a long time , just found a great deal on a 2007 49cc Kymco Super 9.   It was suposedly dead , but I got the engine running great in about  1/2 hour.  Had to repair a bent steering stem and now I am riding it daily.    Here is my problem.    When coasting down a big hill , everything is nice and smooth.   When traveling under power , there is a very noticible vibration.  It feels like a  very out of balance tire or a bent rim , but the rims are fine.    I suspect it is originating in the  CVT.     Could a worn spot in the belt cause this ?    I had the CVT cover off  and the outer clutch bell is not warped or anything.      I am pretty good with mechanical stuff , and probably could figure it out eventually , but I have never even looked at a CVT prior to this , so the opinions and expertise from others will be of great help.    thanks   GORD

[DMblues01]

I don't have any experience with the super9, but my 2012 Super8 150 gets jittery at speed. It's mostly from the stiff suspension on the Super8. Even a "smooth" road feels like a washboard at speed.

If the Super9 has the same stiff ride, then it could just be the road. You may also put it on the center stand and throttle up to see if the rear tire has a wobble.  I've heard a few people talk about certain tires being out of round, and needing replaced.

Also keep in mind, as has been mentioned in another thread, a single cylinder engine is always going to have some vibration when it is running. Especially as the revs get higher.

[gordon_as]

Have spun the wheel up while on the center stand and can see it vibrating the wheel and entire suspension and bike up and down.   The thing is , I am pretty sure it is not the wheel or tire because I can coast down a hill at  40mph with no vibration at all.     As soon as I start moving under motor power , the vibration is there.

[DMblues01]

Then it's most likely just normal single cylinder vibration. Even if the engine is counter-balanced, it's just the way they are. Not much you can do about it, if there is nothing worn or warped in the cvt.
Other than the possibility of an internal engine issue, it may just be the nature of the beast.

[zombie]

I was thinking a worn out variator/rollers. Could also be bad crank bearings or wrist pin. You're gonna have to open up the CVT, and fan side of the engine to try to narrow it down.

I would order a new variator kit w/ rollers, belt, and rear 2000 contra spring. Install that stuff, and see what happens. We can hook you up to get all that stuff for under 100.00
Even if you later find it is a bad crank the bike is worth fixing, and all the stuff for a crank install is under 200.00 including a crank puller. The bike is easily worth 8-900.00. (unless you tell people it has a twisted frame)

[gordon_as]

 a friend who is a motorcycle mechanic had a look and swears that when I replace the badly worn rear tire all my problems will be solved.    Gonna order one tommorow.     Re : the frame  ,  It was not bent , at first I thought i had a bent fork , but when I took it apart I found that it was one side of the steering stem (triple tree )  twisted and holding one fork at a different angel.    Heated it cherry red with a torch , gave it a bit of a twist and reinstalled it.   Expected to have to do it a couple of times to get it right , but it was  perfect after the first try.   Just dumb luck.      The person I bought it off of was one of those who took it to a shop for  service and repairs.   I assume they have allready done some mods because  the rev limiter has obviously been removed / defeated.    She said it would go  95 km/h which is about  58 Mph.    I have had it up to  60 K / 40 mph  and still have lots of throtle left.   I am hesitant to  rev past  6500 rpm ,  don't want to blow it up ,  need it to ride to work all summer as my truck gets  horribly bad fuel mileage. 

[wkreps]

Still doesn't make sense to me. if it is the tire then why would it run smooth downhill (no throttle). At any rate, keep us updated when that new tire gets on there. Hope you're riding (safely) soon.

[gordon_as]

Ya , that was my logic too.   Makes sense to me.    I will put on the new tire (which it needs anyway)  and  hope for the best.

[zombie]

Still doesn't make sense to me. if it is the tire then why would it run smooth downhill (no throttle). At any rate, keep us updated when that new tire gets on there. Hope you're riding (safely) soon.

Why do sooooooooooooooooooo many people tell you 1/2 the story, and then say it was out of gas.
I assume people assume we are all a bunch of clairvoyant a_holes.,

It's broke, and we don't know why. TADA!

[gordon_as]

Hmmmm , don't believe you to be clairvoyant , but the part right after that.......... apparently maybe.      What is wrong with  posing  a legit question to a group that  might just have a good answer ?   

[wkreps]

Why do sooooooooooooooooooo many people tell you 1/2 the story,

Maybe cause they don't know how to tell a story. Translation: I'm new to scooter ownership so when something goes wrong, I may not give all the info needed cause I just don't know what all info to lay out there to give others a good idea on what's going on.

[Stig / Major Tom]

Gents, there are no dumb questions.
I'm living proof of that!
OK, well maybe that's a bad example.
Just saying....
Stig

[zombie]

Gordon... There are indeed no stupid questions IF you really don't know the answer But when you/someone says the bike shakes, and I don't know why/ Then comes back with I don't think it's what you think it is because the tire is "badly" worn... it gets frustrating.

Going on your OP about the neck being twisted it is easy to assume the bike was in a wreck, and potentially broke a weld that you can not see.
The rear wheel out-put shaft can be bent.
A fork could be jammed.
An engine mount broken
An engine mount bushing worn.

There are a hundred more... Everyone that post here helps the community, and LOTS of them have been posting for years. What we ALL have in common is a desire to help, and to some extent common sense.
This leaves me... I don't give a rats arse, and am as dense as a black hole. I just don't have any friends, and since I cry ALOT I have to do something to keep my mind off of my Adult Onset Down Syndrome (AODS) Please understand.

Post up, and chit chat... Shoot the breeze... tell a joke... whatever. But PLEASE don't make me go out and hurt someone cause you already knew what was wrong w/ your bike, and you just didn't want to tell us. It's not fair to that poor random person, or my case worker that has to fill out hundreds of forms every time this happens. With all the love that can be mustered... Z

Ps... Do you have a sister?

[gordon_as]

What make you think I knew what was wrong with the bike ?    I still don't know what is wrong with the bike.     If replacing the tire solves the problem , then I will know what was wrong with the bike.    If you happened to actually read my post , you should have been able to garner enough info to realize that I thought I might have a problem with the CVT , a piece of mechanical equipment that I have  zero experience with.
I will probably be  reading this Kymco forum alot , and may one day realize that you are a great guy and very helpful and knowledgeable , but at the present time I just find you rude and  annoying .   I Read some of your other posts and suspect that I am not the only one who feels this way.     Happy Mother's day

[zombie]

Welcome to the group!

I'm pretty sure I can get my ass kicked in twenty to thirty countries. Fair warning... I have a pocket full of rubber bands, and paper clips.

Happy Moms day back.