NC24 questions

[RHonda]

I have a question about what is the function of two little black sensors in the speedometer of NC24. My father said that this is a photo-cell. Sensors are connected by three wires. Between the sensors, there is a metal disc, controlled by the needle. Is this a 180 km/h restriction? Should I remove the sensors? I have read much about restrictions, but never saw something like this. Other two wires which lead into speedometer are disconnected.

I also want to know about this ECU: http://cgi.ebay.co.uk/Derestrict-CDI-FO ... 9001r34706- this one is for NC30, but is available also for NC24. Does this ECU increase bike's horespower ? How much rpm reaches the bike if you install it ? Is top speed higher ?

Another question: I have installed new engine on my NC24. Now, it revs only to 7000 rpm. With previous engine, there were no such problems. I didn't touch electrics after I unplugged the old engine. Is it possible that there is problem in the carbs (I have been cleaning them) or in electrics? On servis they said that the voltage regulator is not original, should be this a problem ? But before it worked well. I am not sure that regulator is connected properly, should it be to achieve top revs ?
Where can also be a problem ?

[CMSMJ1]

I have a question about what is the function of two little black sensors in the speedometer of NC24. My father said that this is a photo-cell. Sensors are connected by three wires. Between the sensors, there is a metal disc, controlled by the needle. Is this a 180 km/h restriction? Should I remove the sensors? I have read much about restrictions, but never saw something like this. Other two wires which lead into speedometer are disconnected.

I would connect the wires into the speedo first of all - the bike needs to know the speedo is connected or it will not run correctly. The little "half moon" is the 180kmh restrictoin trigger. This can be removed to stop the restriction kicking in

I also want to know about this ECU: http://cgi.ebay.co.uk/Derestrict-CDI-FO ... 9001r34706- this one is for NC30, but is available also for NC24. Does this ECU increase bike's horespower ? How much rpm reaches the bike if you install it ? Is top speed higher ?

That ECU is for the NC30 - the NC24 nd 30 are not as similar as you think. It also does nothing for the speed or power..it removes the 180kmh restriction...and from the experience people on here have had they are not the most reliable.

Another question: I have installed new engine on my NC24. Now, it revs only to 7000 rpm. With previous engine, there were no such problems. I didn't touch electrics after I unplugged the old engine. Is it possible that there is problem in the carbs (I have been cleaning them) or in electrics? On servis they said that the voltage regulator is not original, should be this a problem ? But before it worked well. I am not sure that regulator is connected properly, should it be to achieve top revs ?
Where can also be a problem ?

It does not mater if the regulator is plggued in for the engine to work. The 7000 issue might well be caused by the speedo bein unplugged. On an NC30 this causes the bike to drop to 2 cylinders at 5500 revs. I assume the NC24 has a similar issue.

Welcome to the site too...

[RHonda]

First thank you for the answers.
I dont understand how does this restriction work. Does anyone know what is function of this photocell (two black cubes) ?
Maybe that it triggers electrical contact ??

Picture of the cell


In between the cell is a little metal disc (*the half moon). I took a look in the speedometer and I saw, that from 0 to 80 kmh (not 180!!) there is no disc in between, but from the 80 kmh and to the end, there is (disc rotates). I wonder why not from 180??? I hope that it is not restricted at 80.

Position of disc at 0 kmh


Position of disc at 80 kmh (and to the end)


I want to know, what should I do for restriction? The disc can not be removed, it is fixed. Should I remove the black cell (element on the picture above) from the position or do something else ??? Please help me.

[Lope]

the VFR400 has a speed warning light at >=80km/h because that was the maximum speed limit in japan long ago (or still is perhaps) :) it doesn't limit performance in any way, its only a warning.

VFR400s usually have a RPM restriction at 5500 or 7k rpm or something as CMSMJ1 said above which can be bypassed with a resistor between 2 wires.
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does the wire for the 80km/h warning light just run from the speedo to the light panel? anyone know what colour the wire is?

[RHonda]

Yes, two wires run from the speedo to speed light. One is red/brown and another is brown/black. And there is also the green wire, which runs from the speedo to main connector for the control panel.

I realized that everything I described in previous post, is not the restriction, it is connection with speed warning light.

But there are two another wires which are in speedo, I dont know their function. They are disconnected in my speedo.
Anyone knows their function ??

[Neosophist]

You are confused.

The NC24 is not limited at any speed.

The disc simply lights up the 'Speed' light when the bike reaches 88km/h (55mph), maybe 80km/h (50mph) I can't remember.

This is to let the rider know they are breaking the law (the maximum speed for a bicycle during the NC24 era was 80km/h, this is no longer the case)

Just leave it all connected. You can take the bulb out the 'Speed' light (if it hasn't already) if it bothers you.

The 3 wires for the Speed sensor are 'Power / Earth / Speed Sense Trigger'

There are also 2 bulbs to the speedometer. 3.4 watt and 1.7 watt if I remember correctly.

[RHonda]

I would like to know, if the voltage regulator from another honda bike would be useful for the NC24? I cant buy it anywhere. Do
honda bikes use the same regulator or is it different from model to model ??? Thanks.

[rich1988]

You are confused.


There are also 2 bulbs to the speedometer. 3.4 watt and 1.7 watt if I remember correctly.

That would explain why my speedo is really badly lit, I replaced it with two 1.7 watt equivalent LEDS

[Neosophist]

I would like to know, if the voltage regulator from another honda bike would be useful for the NC24? I cant buy it anywhere. Do
honda bikes use the same regulator or is it different from model to model ??? Thanks.

Yes, fit anything you want as long as it is the same in operation ^_^

Yamaha R6 Regulator (2000-2002) is very popular choice. Big and reliable. Will need to cut wires and SOLDER not crimp spades.

You are confused.


There are also 2 bulbs to the speedometer. 3.4 watt and 1.7 watt if I remember correctly.

That would explain why my speedo is really badly lit, I replaced it with two 1.7 watt equivalent LEDS

Yes thats a bad idea.

The bottom bulb is 1.7watt, the top one is 3.4