Cbr600f 1992 jap import

[Guest]

I have a 1992 cbr600 fn, it reads in kmph. I fitted Uk clocks but now it misfires at 5000 rpm. The old clocks had a black box at the back and a convertor on the speedo cable. Wil i have to re fit the old clocks or is there a way to correct this problem. I would prefer to read in mph without buying a new bike.

Thanks in advance

[Weebl]

Does it always misfire at 5k regardless of gear? Or does it misfire at a certain speed which is 5k revs in top?

[Guest]

Hi mate, Yeah it does it in any gear when it hits 5000rpm. I think I will have to splice the black box onto the new clocks, as that was probably added to the old clocks to derestrict the bike.

[Guest]

Hi mate, Yeah it does it in any gear when it hits 5000rpm. I think I will have to splice the black box onto the new clocks, as that was probably added to the old clocks to derestrict the bike.

[Guest]

Hi mate, Yeah it does it in any gear when it hits 5000rpm. I think I will have to splice the black box onto the new clocks, as that was probably added to the old clocks to derestrict the bike.

[Weebl]

Sounds like it could be, but you have to bear in mind all Japanese Domestic Vehicles are restricted to 180 KPH (112 MPH)

As it is doing it in every gear, then it is not still restricted, but not receiving any signal at all, so going into limp mode (in all probability, it is 'fail safe' so if it does not get a signal saying 'I am not speeding' then it presumes you have unplugged it so goes into limp mode)

If yours is cable drive to the speedo, then it will collect it's speed signal from the clocks, and your UK clocks will not have the speed sensing device in them at all, so splicing the box back in will not fool anything. (normally, when you de-restrict you don't actually remove the restrictor, you just change to MPH so the restrictor is pushed up to 180 MPH from 180 KPH.)

I am not 100% sure what you mean by saying you want MPH readings? That should have been sorted when you had the KPH speedo converted? If it still read in KPH and not MPH then it was never derestricted and the black box is not for that.

First thing to check is that you have not blown the fuse while changing the clocks, do they work ok? Lights in them and everything? Check the fuse box and the one for 'meters' is what you are looking for If the fuse has gone then no signal

If that does not fix it/fuse not blown then;

I had a quick google and found the speed signal lines in your ECU (as long as they all use the same colour codes)

What you need to do to feed the constant 'I am not going faster than 180' signal. Locate the ECU connector, you should have 2 wires, one Brown/Blue, one Black/White. You need to cut the Brown/Blue and then strip a bit of insulation from the wire at the ECU end. Then strip some insulation from the Black/White without breaking the line The solder a 2K ohm resistor between the Brown/Blue wire (ECU end) to the Black/White line.

If that fixes it, remember to clean up where you have been fiddling with insulation tape etc

[Guest]

Thanks for that, the main reason I changed to uk clocks was that the jap version wasn't correct. When I was doing 30mph the needle was at 25 kmph. Very confusing and also I prefer the speedo to be Uk spec. I have only had problems since I changed them over and removed the speed convertor from the cable itself. Could it be that?

[Weebl]

Thanks for that, the main reason I changed to uk clocks was that the jap version wasn't correct. When I was doing 30mph the needle was at 25 kmph. Very confusing and also I prefer the speedo to be Uk spec. I have only had problems since I changed them over and removed the speed convertor from the cable itself. Could it be that?

 

Unlikely. And if you leave the speed convertor on, you will be indicating very low, like 30 MPH at 50MPH low.

Like I said, odds on it is expecting a 'not speeding' signal from the clocks, and you don't have any speed feedback in your UK clocks.

Don't be surprised if it still reads low either. most bikes reading 30MPH are only doing a genuine 27MPH. I just expect that your KPH/MPH convertor was exacerbating that effect a bit.

[Guest]

Thanks again for that, i have swapped the circuit board attached to the jap speedo to the uk speedo and swapped over the jap wiring loom with the black box. Hopefully that will work! I'll post later to let you know.

Cheers

[Guest]

Hi all, it worked, thanks for all your advice.