Author Topic: Shudder and Growl (re-posted from the Yager forum)  (Read 2705 times)

ScooterWolf

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Shudder and Growl (re-posted from the Yager forum)
« on: April 22, 2011, 06:14:35 PM »
Okay, I've hit 3000 + miles on my Yager GT200i. I figure that's roughy equal to one cross country trip from coast to coast here in the US. About a month ago my back fender blew out. Something blew off the left side screw mount while I was crossing the Ben Franklin Bridge doing about 57 MPH. The plastic fender came to rest on my rear tire where a good part of it melted away from the friction. There wasn't much left when I got home and took it off.

Took the scooter to my dealer who replaced the fender and did a service check -- it was time for it anyway. The blown fender had knocked loose a valve module -- not enough for the engine light to go on, but enough for air to get mixed where it shouldn't be. He fixed it, changed the oil, plugs, etc ... and I had the scooter back within 3 days.

Now I've been noticing a new problem. When giving the throttle gas the scooter will run, but when it gets to 7 mph it begins to shudder with a rattling growl, then lurches faster like its shifting to a higher gear, then runs normal. At first I thought it may have been from cold air passing into the engine, but even now in the warmer weather it happens. Some days are worse than others, but regardless it continues to happen.

Engine mechanics is not my forte. Is this a fuel line problem, carburetor, timing belt, or something else?

-Wolf
« Last Edit: January 30, 2012, 03:19:06 AM by ScooterWolf »

axy

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Re: Shudder and Growl (re-posted for the Yager forum)
« Reply #1 on: April 22, 2011, 07:29:33 PM »
None of what you suggested.

Flat roller weight manifests in the way you described, but your mileage is too low for this to happen.

I would check the roller weights in the face plate of the front drive pulley.
---
Kymco People GT300i 2017 ABS Euro4
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)

ScooterWolf

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Re: Shudder and Growl (re-posted for the Yager forum)
« Reply #2 on: April 25, 2011, 09:11:13 PM »
Axy,

Thanks for the advice. Oddly enough the problems seems to have gone away. I wonder if it was weather/temperature relate? If it occurs again I'll look into your suggestion.

Thanks,

-Wolf

Wil B.

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Re: Shudder and Growl (re-posted for the Yager forum)
« Reply #3 on: January 26, 2012, 01:32:33 PM »
I myself experienced the 'shudder' at 7-8 mph at the 6 month 1,200 mile mark.  I finally got it to the dealer (my local Honda dealer) who cleaned out the trans pulleys full of belt dust & glaze.  The mechanic says it's a common problem on larger scoots.  I think I could open up the trans case and clean things out myself if this happens again.   This is the only problem I've had with my Yager 200 gt.

Wil B.
Broadview, IL
Wil B.

2010 Kymco Yager 200
2004 Ktmco Super 9
2014 Honda CTX
"I am not a number. I'm a FREE MAN!"

ScooterWolf

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Re: Shudder and Growl (re-posted for the Yager forum)
« Reply #4 on: January 26, 2012, 03:10:00 PM »
Will,

I'm approaching the 7000 mile mark on my scooter at which point I'll bring it in to the dealer for a service check up -- change of trans fluid, spark plugs, and I may need some brake fluid too. The fix to my shudder problem was with the roller weights which were off balance and asymmetrical. They were replace and the problem is now gone. Right now my only sticking point seems to be moisture in the gas tank from the ethanol in the gas. It causes the bike to have a drop in engine power and at random moments. If I floor the throttle at the moment it happens I can power through it. I do notice it happens the most if it's rainy or damp and I fill up the tank.

Wil B.

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Re: Shudder and Growl (re-posted for the Yager forum)
« Reply #5 on: January 26, 2012, 07:18:53 PM »
Scooterwolf,   Thank You,  I'll remember the roller weights if this happens again.  Although I won't be riding until March (Chicago weather) I hope to put a lot of miles on the Yager this summer maybe even a small camping trip.

Sometimes a drop in power ONLY when it's damp can indicate a bad electrical connection.  Just a thought.  I'm not sure what filling up the tank would have to do with it, but if you get bad gas, it can really screw up things and even shut down the engine.  Let us know what your mechanic says.

Thanks
Wil B.
Broadview, IL
Wil B.

2010 Kymco Yager 200
2004 Ktmco Super 9
2014 Honda CTX
"I am not a number. I'm a FREE MAN!"

ScooterWolf

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Re: Shudder and Growl (re-posted for the Yager forum)
« Reply #6 on: January 27, 2012, 01:19:13 AM »
Not sure if there really is a connection to the gas up and power loss, unless the dampness makes the ethenol absorb more water, but I'm not much of a mechanic.

I'm actually looking forward to a trip to the Jersey shore this summer -- some place better than where Snooki and gang hang out.

-Wolf

zombie

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Re: Shudder and Growl (re-posted for the Yager forum)
« Reply #7 on: January 27, 2012, 01:54:54 AM »
This may sound like a bit of a reach but here goes... Water that gets absorbed into the ethanol will not burn but convert to steam in the cylinder during compression. This does (2) things, Increases compression ratio, and at the same time washes the oil from the Cyl. walls. During the winter months the BULK fuel containers, and transporters will be exposed to temp. swings that induce condensation inside them. Therefore there is more captured water in the fuel supply. Same goes for the scoot itself. Condensation will accumulate in the fuel tank from hot riding, and cold storage. a 1/2oz. of Seafoam in every tank should get you thru the winter. Also keep the tank topped off before you shut it down for the nite. this will prevent alot of the condensation. Above ground storage, and over the road containers are the MOST susceptible to this. Below ground containers are less prone to Temp. changes.
"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...

ScooterWolf

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Re: Shudder and Growl (re-posted for the Yager forum)
« Reply #8 on: January 27, 2012, 06:21:08 PM »
Great advice, Zombie, though keeping the gas topped off at night may not be as convenient as I like. Sometimes I return home around 10 at night, and our detached garage has no power or lights, so adding gas in the dark might be a problem.

I've heard mixed reviews on sea foam. Has anyone used it with good results?

-Wolf
« Last Edit: January 28, 2012, 12:44:46 AM by ScooterWolf »

fshfindr

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Re: Shudder and Growl (re-posted for the Yager forum)
« Reply #9 on: January 27, 2012, 08:54:03 PM »
Great advice, Zombie, though keeping the gas topped off at night may not be as convenient as I like. Sometimes I return home around 10 at night, and our detached garage has no power of lights, so adding gas in the dark might be a problem.

I've heard mixed reviews on sea foam. Has anyone used it with good results?

-Wolf
I used it in one tankfull.  It may have been my imagination, but the bike seemed to jump more when I gave it a twist.  I am finding it hard to believe, but it did happen and if not the SeaFoam, I don't know why. 

I haven't gotten gas in Phila yet, but if you know where they are mixing reg. with high test, PM me.
Richard L. in Bellmawr
Keep The Rubber Side Down & The Helmet Side Up

zombie

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Re: Shudder and Growl (re-posted for the Yager forum)
« Reply #10 on: January 27, 2012, 09:33:38 PM »
Hey Scoot, I have a wife that is not that convenient either... Wanna rent out your garage?
"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...

ScooterWolf

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Re: Shudder and Growl (re-posted for the Yager forum)
« Reply #11 on: January 28, 2012, 12:47:25 AM »
Ba-dom-bong!

On the garage, Just be careful with her when entering in the night  ;)

-Wolf

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