UK Spec NC30 - Limp Home mode

[NGneer]

Calling all electrikery boffins - HELP!

Yesterday i picked up my latest aquestition ie a UK spec NC30 with Tyga tail unit LED rear light etc etc. I never intended to keep the Tyga rear end on the bike as it is not my taste, but in work today and found outi am going overseas again - Arghhhhh!



As such my plans for a UK SPec rebuild have been binned and i am now just looking at shifting the bike on so i only have the two to mothball when i go (anyone want a UK NC30?).

I had already started removing the Tyga seat unit sub frame etc and replacing it with the OEM stuff so i decided to finish that, put some spare fairings onto it (that i had lying around) with the intention of then putting it up for sale and selling the Tyga unit seperately.

Finished swaping things over and whilst the bike starts and runs ok - as soon as you put any load on the engine it goes to (what i assume is) the limp home mode. It was perfect before the swap over so i am thinking it is somthing i have or have not done.

The previous owner had cut some of the wiring and redone the terminations with bullet connectors to accomodate the LED rear light and dinky indicators. I have modified the normal rear light wiring to bullets and sleeves and that seems to work fine.

As he had an LED rear light before - is there something i should be looking for (resistor/diode etc) that i now need to remove from the sysytem as we are back onto normal tail/brake lights?

I havn't yet done the indicators - would this have an effect?

Also as this is a UK bike there are two extra wires at the back end for the number plate light. I was not going to bother with this and was just going to tape the wires out of the way. Would not being conected through a light cause a limp home mode?

Whilst re routing the wires aftere the sub frame went back on i disconected the HT leads on the back cylinders for ease of access. Not sure if i got them the right way around when they went back - but can' t decide if this would make any difference. Do both cylinders fire at the same time (ie both rears) or is it x1 rear and x1 front that fire in pairs - i never can remember.

I am sure i am just 1 wire away from it being back on song - so any help greatfully recived

[mick.mh2racing]

Not sure but I thought the limp home mode was only if the speedo or the ignition circuit was tampered with.
And by limp home mode you mean it won't rev past 5000 rpm? If that's the case I should retrace your footsteps, something as simple as a wire shorting out will have caused a fuse to blow. Fuses might be one of the first things to check. Replace it and see if it blows again when you perform a particular task.
I speak from slight experience here. My ignition fuse kept blowing when I grabbed the brakes. Turned out the rear brake switch had melted on the exhaust and caused a short and kept doing the fuse.
Good luck.

[Jon]

Indicators and tail light wiring shouldnt have any effect.

HT leads either way shouldnt worry it either as wasted spark system.

You didnt swap the low tension leads around on the coil?
They will work reversed polarity but not a strong a spark.

Good earth on the coil? guess it is still mounted on rear subframe?

Sorry couldnt be more help.

jon

[CRM]

Hang on, this is a UK bike and as such doesnt have the restrictor circuit. so that bit of the loom and different CDI means no restriction.
i wonder if it has a jap loom and CDI and if coupled with MPH clocks and no restrictor then this is where the problems slipping in.

try your aftermarket CDI on it to rule out the restrictor.

[NGneer]

Hang on, this is a UK bike and as such doesnt have the restrictor circuit. so that bit of the loom and different CDI means no restriction.
i wonder if it has a jap loom and CDI and if coupled with MPH clocks and no restrictor then this is where the problems slipping in.

try your aftermarket CDI on it to rule out the restrictor.

Sorry i think i confused you there - not saying it has a restrictor or anything like that, just thinking (typing) aloud

As i say the bike was running spot on until i swapped the Tyga seat unit back to the standard one. In doing so i moved a few wires but didn't really break into anything so i figure whatever it is, is only a small thing. About to go and have another hour or so checking conections and earths etc. Wish me luck

[dog the gixer hunter]

A few years ago I had a loan of an nc for a hill climb.While tinkering with it it suddenly started running like shite.Turned out the brake light wires had shorted on the exhaust and blew the fuse.One new fuse later we was back in buisness.Check the fuses.

[NGneer]

Yayyyy sorted it, but i guess i must admit to some muppetry.

Took the seat unit of and was working my way through all the connections cleaning them and checking they were a good fit when i reached the rear coils. Again i was going to clean and check all the connections when i decided that actually having the low tension spade connectors CONNECTED might also help - Dohhhh!

Plugged in - fired up - went like train.