RVF not firing on front cylinders

[big fat fish]

Right, all this started with a rotten front coil. The bike was missing on 1 cylinder, took the coil off to check it, and one of the pins that the HT lead screws to had rotten away. I've replaced the coil with a new one, amd trimmed the rotten ends off the HT leads. all resistance readings check out ok, but the bike is now not running on front cylinders. The coil resistances check out ok, the resistance on the pulse generators checks out ok, and wire continuity is ok, there is 12v at the coil. bike starts and runs on the rear cylinders, you can unplug the coil and it makes no difference to the running of the bike. (I admit I have yet to swap the coils over to test the new coil-for now we'll assume the coil is ok until i get to work to test it tomorrow)

My bike is deristricted (before i bought it) There is a little black box spliced into the cdi wiring. why? what is it, how do i test it, I am assuming it's part of the de-restrict kit. Right now, I'm assuming this is the faulty part, but have no idea of how to diagnose the fault

(I am a car mechanic so have an idea of how it all works, but my next port of call before getting the cdi tested is to check out this wiring mod) The speedo has been apart and has the little tab bent back, so surely there is no need for the 'black box' in the wiring loom? Any help would be appreciated


Cheers

Fish

[MexicanGringo]

Hey fish, just to be sure it is the fronts not firing, take one of the fronts and one of the rears out and touch them against the frame & crank engine to see which ones spark, maybe check them all to be completely sure.. The derestrictor is usually some arrangement of resistors, tho if it was working fine before this shudnt have died.. Prob not reg/rect if the rears are firing fine.. Are the plugs ok? They need to be quite clean on an NC to work properly. Ur a mechanic so uv prob checkd that.. Maybe check secondary resistances again using the ends of the HT leads rather than at the terminals, that way you know the cables and connections are fine.. Otherwise check wiring, the coils have a live connection to the stop switch, and the cdi to the pulse generators which may be loose/corroded.. Fuses? nay, you already checked them?

[Freekazoid]

i had same prob on my NC30 with plugs not firing. but that was due to age & dirt, the spacing i thing is supposed to be 0.6-0.7 but don't hold me to it. chances are good that the plugs are poped because of the how difficult it is to change the front plugs (assuming it is the same as the NC30?) i know that plugs are expensive but in comparison to a coil it's cheaper so why not start off replacing the plugs & seeing if that fixes it if not move on to the next part?

[big fat fish]

I'm checking the plugs tomorrow, (yeah i know you're supposed to do the simple stuff first )........the plugs are 500 miles old so assumed they're ok, having read other threads over the last day or 2, it seems they are a bit........fragile. Especially if the engine flooded, which moving it about with poor spark/buggered coil could do. I like my electrical work and seeing this black box concerned me and i wanted to know how to test it. I know for certain the front coil was poked, as the pin for the HT lead had completely rotted away, just a shame it looks like it took the plugs down too....

Just my luck it's the front plugs too!

bloody bike.....get my freshly painted and repaired fairing back soon, and then she'll be ready for the road again...

cheers

Fish

[Cammo]

Hey mate, there's a pretty good chance your front plugs will be stuffed since lots of petrol will have been going in there without a spark to burn it off.

You're right, the plugs can be trouble when flooded. Let's hope this is your problem!

The black box will more than likely be a derestrictor to get around the 180 km/h speed limiter. They're a simple bit of gear (a restrictor bridging 2 of the cdi's wires) and shouldn't cause too much worry.