Honda Vision 50 2011 losing RPM and speed going uphill

[gvnlpt]

Advise needed!
Been riding my Honda Vision since April 2024 and everything was fine, however today on my daily commute to college spotted that speed on flat decreased from about 30mph on a speedo to about 28mph and through most of the ride engine was NOT working as loud as it normally would. Sometimes it was getting short bursts of full RPM but not for more that 10 seconds and then it'll go back to being limbed again. The worst part happened when i reached one of the hills. RPM sounded like it dropped to almost idling numbers and speed was about 8-10mph. Also worth mentioning that speed downhill reduced significantly as well (about 5mph less than normal).
Rider: 6"0 90kg = 200 pounds = 14 stone
Load carried - none
Wind - minimal
Any advise will be appreciated!
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Honda Vision 50 2011

[jaffa90]

Sounds to be short of fuel at high revs, is the fuel tap vacuum operated (any pics) and are the fuel filters clear / clean ?

[gvnlpt]

[WD Forte]

2011 eh so is that EFI or carbed?
what's the mileage and when were the belt and rollers last checked?
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bikers smell of wee

[Nobby the Bastard]

Im impressed that a moped could even get 14 stone up to 28 mph.
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trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[A100man]

has it got any oil in it?
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Now: A100, GT250A, XJ598, FZ750

Then: Fizz, RS200, KL250, XJ550, Laverda Alpina, XJ600, FZS600

[WD Forte]

had a quick look and it's probably EFI
as its 2011 and 50cc which suggests 'yoof' owned or ridden
its probably worn out or suffered much neglect
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bikers smell of wee

[gvnlpt]

[gvnlpt]

[gvnlpt]

[stinkwheel]

Make sure it's not something stupid like a brake dragging.

Also have a check of the sparkplug electrode, see what colour it's looking like which can indicate a fuelling issue or if it's burning oil.

Does it use oil? Any smoke from the exhaust?

Air filter clean and clear? No water, oil or fuel in the airbox?

Might be worth doing a compression test and checking the valve clearances.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[WD Forte]

I the eml (engine warning) light on?
It should come on briefly at switch on then go off
within a few seconds.
if it detects a not too serious fault it will stay on as you ride.
IAT or 02 sensor gone wonky for instance
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bikers smell of wee

[gvnlpt]

[gvnlpt]

[WD Forte]

I dont know the 50 but did lot of work on a 2018 Vision 110 and
will assume they have a lot of similarites.
Sensor wise it had the bare minmum to run EFI as I recall
and had clocked up 65000 Deliveroo miles and still sounded sweet.
Whether the 50 would have same long service life is an unknown.

I also recall the rear mudgaurd not being very good and the wheel threw all manner of shite over the engine around the throttle body area which I had to clean out from time to time.
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bikers smell of wee

[jeffyjeff]

Fuel system might be losing pressure through an internal leak inside the tank. If anyone has been in there before, to replace a fuel filter for example, an internal leak could be suspect. Internal fuel line needs to be rated for 'submersible' use. Regular fuel line will degrade when submersed in fuel, and eventually leak; if on the pressure side of the pump, resulting in low fuel pressure.
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History shows again and again how nature points out the folly of men - BOC

[slowasyoulike]

I wouldn't dismiss the compression test, you can get a viable tester on eBay for £11:

https://www.ebay.co.uk/itm/394118183625

and if the result comes back that it's fucked, then it saves you doing most of the other checks people have suggested.