Engine revving while braking
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Hooked
2016 MP3 500 Sport
Joined: 21 Jun 2007
Posts: 110
Location: Indianapolis, Indiana
Fri Jun 14, 2019 11:21 am quote
My 2016 MP3 500 Sport continues to rev when I let off the throttle. When I brake, it seems like the brakes are fighting the engine. Shouldn't the revs drop as soon as I let off the throttle?

Thanks

Marty
Hooked
2019 MP3 500hpe Sport
Joined: 03 Nov 2014
Posts: 451
Location: Germany
Sat Jun 15, 2019 10:21 pm quote
what do you mean by continues to rev?

There is engine braking until the revs get down to about 2400rpm or so then the clutch releases and then it coasts...if that makes sense.
Hooked
2016 MP3 500 Sport
Joined: 21 Jun 2007
Posts: 110
Location: Indianapolis, Indiana
Sun Jun 16, 2019 7:19 am quote
Thanks!

It feels like the throttle is trying to accelerate while the brakes are applied. It doesn't feel like engine braking.
Ossessionato
BV350, Primavera 150, Yamaha Zuma 125
Joined: 06 Jun 2013
Posts: 2800
Location: The Twin Cities of Minneapolis/Saint Paul, Minnesota
Sun Jun 16, 2019 7:35 am quote
You're not rolling on the throttle as you're applying the brakes, are you?

Does the throttle snap all the way closed when you release the grip?
Hooked
2016 MP3 500 Sport
Joined: 21 Jun 2007
Posts: 110
Location: Indianapolis, Indiana
Sun Jun 16, 2019 7:39 am quote
I'm not rolling on the throttle at all and it does close, but I wouldn't say it snaps.

Thanks!
Veni, Vidi, Posti
Neutrino MP3 492.7 AK, 2013 Moto Guzzi Norge
Joined: 29 Mar 2008
Posts: 21367
Location: Harriman, Tennessee, Tn
Sun Jun 16, 2019 10:30 am quote
drawnon wrote:
I'm not rolling on the throttle at all and it does close, but I wouldn't say it snaps.

Thanks!
you might have a cable off or not working properly.

this is a push/pull throttle system so you have 2 cables.
Hooked
2019 MP3 hpe 500 sport Advanced " Missy "
Joined: 21 Dec 2018
Posts: 203
Location: West Germany
Sun Jun 16, 2019 10:42 am quote
It could be a sticky Throttle Cable. I would get it looked at A.S.A.P. It could become a Run away. So be careful!
Moderaptor
The Hornet (GT200, aka Love Bug) and 'Dimples' - a GTS 300
Joined: 26 Aug 2007
Posts: 37557
Location: Pleasant Hill, CA
Sun Jun 16, 2019 2:44 pm quote
And don't just replace one throttle cable - replace them both! If one has gone AWOL then the other won't be far behind. BTDTGTTS, but my duff cable was the ON one rather than the OFF one. Stranded on a UK motorway for half-an-hour until the tow arrived.
Hooked
2016 MP3 500 Sport
Joined: 21 Jun 2007
Posts: 110
Location: Indianapolis, Indiana
Sun Jun 16, 2019 7:58 pm quote
Thanks guys,

I'll have the throttle cables checked this week.

Marty
Molto Verboso
Kymco AK550
Joined: 09 Feb 2008
Posts: 1113
Location: UK
Mon Jun 17, 2019 1:02 am quote
Yes it happened to me.

If the cable is not lubricated ( they are installed dry and have tight rubber seals over the ends) it tends to corrode mostly near the right angled metal sleeve in the engine compartment. The cable frays and starts to bind then eventually snaps. After the first time I was careful to slide the rubber seal out of the way and run some oil in from the engine end. No further problem in six years. The other cable should provide positive closure but may not be correctly adjusted. When you snap the throttle shut with engine off you should be able to hear a crisp click as it hits the throttle stop. Repeat this test on full lock to make sure adjustment is not too tight.
Hooked
2016 MP3 500 Sport
Joined: 21 Jun 2007
Posts: 110
Location: Indianapolis, Indiana
Mon Jun 17, 2019 5:47 am quote
Thanks. That sounds like it might be the problem. I'll see if I can find where to lubricate the cables.

Marty
Hooked
2016 MP3 500 Sport
Joined: 21 Jun 2007
Posts: 110
Location: Indianapolis, Indiana
Mon Jun 17, 2019 9:25 am quote
Hey guys,

Thanks for your suggestions for my throttle problem. I took the front dash off and lubricated the cables at the throttle with white lithium grease. Now, my throttle is very smooth and snaps back when I release it. Unfortunately, it didn't affect my revs staying high while braking. I don't seem to be getting any engine braking at all. It still feels like the engine is continuing to power the bike until I am nearly stopped.

Marty
Moderaptor
The Hornet (GT200, aka Love Bug) and 'Dimples' - a GTS 300
Joined: 26 Aug 2007
Posts: 37557
Location: Pleasant Hill, CA
Mon Jun 17, 2019 9:39 am quote
drawnon wrote:
Hey guys,

Thanks for your suggestions for my throttle problem. I took the front dash off and lubricated the cables at the throttle with white lithium grease. Now, my throttle is very smooth and snaps back when I release it. Unfortunately, it didn't affect my revs staying high while braking. I don't seem to be getting any engine braking at all. It still feels like the engine is continuing to power the bike until I am nearly stopped.

Marty
Check the other end of the cables, that's where the problems usually arise.
Hooked
2016 MP3 500 Sport
Joined: 21 Jun 2007
Posts: 110
Location: Indianapolis, Indiana
Mon Jun 17, 2019 9:40 am quote
How do I get to the other end? Do I have to remove body panels?

Thanks!

Marty
Moderaptor
The Hornet (GT200, aka Love Bug) and 'Dimples' - a GTS 300
Joined: 26 Aug 2007
Posts: 37557
Location: Pleasant Hill, CA
Mon Jun 17, 2019 9:45 am quote
drawnon wrote:
How do I get to the other end? Do I have to remove body panels?

Thanks!

Marty
Yes. Doesn't take too long, just a bit of a phaff.
Hooked
2016 MP3 500 Sport
Joined: 21 Jun 2007
Posts: 110
Location: Indianapolis, Indiana
Mon Jun 17, 2019 9:47 am quote
Where do I start to get to the engine side of the cables?
Moderaptor
The Hornet (GT200, aka Love Bug) and 'Dimples' - a GTS 300
Joined: 26 Aug 2007
Posts: 37557
Location: Pleasant Hill, CA
Mon Jun 17, 2019 3:22 pm quote
drawnon wrote:
Where do I start to get to the engine side of the cables?
You could read the workshop manual for starters...

Basically start at the back. I misremember if you have to take the seat and front tunnel cover off - possibly not.
Hooked
2016 MP3 500 Sport
Joined: 21 Jun 2007
Posts: 110
Location: Indianapolis, Indiana
Mon Jun 17, 2019 3:42 pm quote
Thanks. I started with the workshop manual but couldn't find anything about the rear throttle cables.

Marty
Molto Verboso
Kymco AK550
Joined: 09 Feb 2008
Posts: 1113
Location: UK
Tue Jun 18, 2019 12:09 am quote
If the throttle snaps back when released I don't think it is the cause of what you describe. This can be confirmed by watching and listening to the cable drum via the engine access panel under the seat.
You may have some form of air leak into the inlet which bypasses the throttle butterfly after it closes. There are also many other possibilities but it would be unwise to speculate without further hands on testing. Can you reproduce this behaviour when the scooter is on the centre stand? ( Place a weight on the seat to override the rev limiting sensor).
Hooked
2019 MP3 hpe 500 sport Advanced " Missy "
Joined: 21 Dec 2018
Posts: 203
Location: West Germany
Tue Jun 18, 2019 2:22 am quote
roadster wrote:
If the throttle snaps back when released I don't think it is the cause of what you describe. This can be confirmed by watching and listening to the cable drum via the engine access panel under the seat.
You may have some form of air leak into the inlet which bypasses the throttle butterfly after it closes. There are also many other possibilities but it would be unwise to speculate without further hands on testing. Can you reproduce this behaviour when the scooter is on the centre stand? ( Place a weight on the seat to override the rev limiting sensor).
Hello roadster. He doesnt really need to put something on his seat. He just needs to turn off his Rolllock before testing.
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