KymcoForum.com
Scooters - 125 to 300 => Downtown 300 => Topic started by: Snorvey on January 07, 2020, 07:04:00 PM
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Riding home tonight, about 100 yards from my house, the Kymco developed a sudden vibration and a loss of power. It still went forward but if it was a 4 cylinder bike I'd think it was only running on 3 - That kind of feeling.
To cold to go into the shed at this time of night, so it'll have to wait until the weekend.
I fear the worst.....
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Waiting for your report and to render any assistance possible. Please say it was like a four running on three with no clanking noises, like a plug wire fell off! Could it be a stuck vent valve to the gas tank (my current favorite harp!)?
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Thank Karl.
There was no clunking sounds that, after some reflective thought, makes me think it was something 'horrible going on in the motor.
Your stuck valve could explain it. Fingers crossed anyway.
Update coming soon.....
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Considering how really well these things are made it seems unlikely any mechanical failure in the engine. Considering the pesky failure rate of the cursed vacuum vent valve and the voltage requirements of the ECU (any below 10.5 vdc spark becomes iffy) points to fuel starvation and ignition failure. Holding breath until your reply (wheeze!)!
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Thanks again Karl. Your number is on speedial :)
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H2O in the tank?
Stig
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Ok so status update.
The DT starts well and there are no nasty noises coming from the motor. Up on the mainstand it revs as normal.
So I took out out for a short blast. At low speed, negotiating the narrow streets and speed humps around my house, it felt horrible - particularly on part throttle. It squeaks and vibrates and forward drive feels terrible - but crucially the engine feels alright.
Out on the open road, the motor feels fine, all the way up to (briefly) top speed*. In fact the whole bike feels fine. temp guage is good
So it feels like something has broken/snapped/come loose. Like an engine mounting or something in the final transmission perhaps.
A quick visual with a torch didn't show anything obvious. I was going to take the plastic off anyway for a bit of a refurb, so hopefully I'll find out then what is wrong with it. That can wait until its a bit warmer though. In the meantime I have a back up plan in the shape of a second hand Toyota :-)
Any thoughts in the meantime (Karl/Stig) are most welcome.
*Yes, I know it's not a good idea to take it up to top speed if there is something loose.....but it's done now.
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Stig's idea of water in the fuel has possibility written all over it! We await your next post....!
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Thanks Karl/Stig.
I'll get the fuel drained and some fresh petrol in there. A cheap fix to try first at least.
I'll keep you updated.
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"...something might be broken,... let's go wide-open-throttle!...."
Keep the go-pro filming, this could be a top scoring youtube!!!
Title it, "Uh-ho!"
Make your surviving family members famous!
You're a nut.
Stig
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Livin" on the edge.
When I grow up I wanna be an air force test pilot.
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Belt and rollers ?
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The belt is only about a 1000 miles old (OEM). Dunno about the rollers.
I've ordered a hand fuel pump and container from the Bezos Tax Efficient Retirement fund, so I'll look at that first.