Rev counter issue

[Farmingstock]

Hello all

I have a Rieju 50cc and it has a strange issue with its Rev counter.

On tick over the Rev counter doesn’t register anything however when I Rev the bike it then works, I’m not sure if the counter has been messed with as this is how I bought the bike (was a none runner)

Also, not sure if it’s related but the coolant sensor light is permanently on, if I unplug the wire from the sensor it goes off, I’ve ordered a new sensor but just thought I’d mention it just in case they are related.

[stinkwheel]

I wonder if the battery is getting flat and it's not making enough power to run the rev counter until you rev it up a bit.
____________________
“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.

[xX-Alex-Xx]

Dodgy earth. Check yo wires.
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DILLIGAF

[jeffyjeff]

Coolant light sounds like a bad sensor to me. Remove the lead from the sensor and touch it to the engine. The light should illuminate, confirming a bad sensor.
____________________
History shows again and again how nature points out the folly of men - BOC

[Farmingstock]

Tried putting the wire directly to head and the light came on so looking like the sensor.

Can’t seem to figure out the Rev counter.

[jeffyjeff]

Well, without seeing a wiring diagram, I would suspect that the tachometer signal comes directly from the ignition module. You can check for dodgy connections or damaged terminal pins/connector in the circuit that signals the tach.
____________________
History shows again and again how nature points out the folly of men - BOC

[Nobby the Bastard]

There's usually a earth and a 12v feed on the meters that provides a basis of comparison to the signal coming from the ingnitor. I'd check that they are both working.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Sprint ST 1050

[Farmingstock]

This is the only wiring diagram I can find, there is no cdi as such just an igniter and a regulator any idea which wires to check??

[Nobby the Bastard]

That wiring diagram doesn't seem to have an electronic speedo or any wiring for a rev counter.

I say that because neither are on the wiring diagram.


Therefore it's the wrong one.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Sprint ST 1050

[Farmingstock]

[Farmingstock]

There are only a few wires that go to
The dash, I have tested most which go to things like headlight, indicators, warning lights but none that if I put power/earth to it makes the Rev counter move at all, would there be a signal I can check for with multimeter to find which wire it is to trace back? Could be the dash, the Rev counter revs round but is 2000 ish behind.

[Farmingstock]

Found this diagram

[Nobby the Bastard]

As I said, there are 3 wires to the guage, a +ve and -ve which are references values and a feed from the ignition pulse. I would check the earth.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Sprint ST 1050

[Farmingstock]

Earth and live both fine, stable readings from the wiring plug, there are two yellow wires, what voltage etc should be coming out of the plug? On the diagram it shows yellow - what reading should I check?

Thanks

[Nobby the Bastard]

You don't check for voltage when checking an earth, you check for continuity....
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Sprint ST 1050

[Farmingstock]

So it should be a reading of continuity from the yellow wires? Obviously asking for advice as I’m not 100% sure what to do.

Check continuity from the rectifier to the end of the lead that plugs into tacho?

Should it move with revs if fine?

[Nobby the Bastard]

The earth needs to be checked for continuity, and the earth is normally black.

The yellow needs to be measured in voltage and it will go up as the revs increase.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Sprint ST 1050

[Farmingstock]

This is what happens

[Nobby the Bastard]

How about take the meter apart, pull off the needle, and then put it back on pointing in the right place?
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Sprint ST 1050

[Farmingstock]

Bought replacement clocks and the issue is still there, any other ideas? Tried moving the dial however it has a keyway and is stuck in that position!

Must be something else somewhere?

[Easy-X]

If an electric-pulse based rev counter is not working correctly and you've tried a new one then the only other inputs are the RPM signal and the main electricity supply (low-volts, noise.)
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Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[Nobby the Bastard]

As I previously said there are three wires.

1)12v. This is a reference voltage.you either have 12v on that wire or not. Easy to check.
2) pulse for the rev reading. This comes from the lt of the ignition soit either works or your bike doesn't run.
3) an Earth. This is also a referencenas well as an earth for the pulse.


As the reading is going lower than the minimum measurement of zero volts (zero revs) I would suspect the earth.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Sprint ST 1050

[Nobby the Bastard]

The coolent sensor light being on is the rev counter using the bulb to find an earth.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Sprint ST 1050

[Farmingstock]

The live is fine
The earth is fine
The pulse is sporadic- this is what I need help checking, is it a case of multimeter on 12v check (same as checking battery voltage)? Wire to earth and other wire to pulse wire?

As can be seen in the video above this is what I did then and it shows voltage?

Are there any other parts to try and change/check to fix this? Diagram above shows wiring?




###The coolant light was the sensor I have changed that and cured the coolant light problem now###

[Nobby the Bastard]

If the pulse wasn't working or sporadic, the needle would stay showing zero revs or drop to zero. It wouldn't go lower than zero.

The fact that it's going 'negative' implies that the reference zero volts (the earth) in't working correctly.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Sprint ST 1050