NC24 electrics fried!! Please help!!

[Utopic]

Hi folks, here goes my first post...

I bought a '87 NC24 with Repsol colours and she's an absolute beaut!! Now the seller pointed out the problems and I discovered a few of my own too. The following components were completely fried and I bought all the replacements today: CDI, Reg/rec and starter solenoid.

Now my first question is why did the starter solenoid blow?? I understand that the reg/rec overheats and often blows but the solenoid is completely anihilated!!

My second question is how do I test the resistance of the stator coils?? I don't know a thing about testing but I have located it. I just need to know where I need to place the positive and negative leads to get the readings.

My final question is how can I tell if the CDI I bought is working before I install it??

I'm looking forward to any advice you guys could offer to help me get my baby on the road!!!

[Neosophist]

You can't really test the ignition box.

I hope the Ignition box and Reg / Rec wern't those cheap ones from China off ebay as you'd be better of setting fire to your money.

How do you know the igntion box is broken?

It sounds like it's had a really bad short somewhere.

First off..

Disconnect the plug to the reg/rec, the one with 3 yellow wires to it.

Call these wires A, B and C.

Get a multimeter and set it to Ohms.. if it's a manual setting put it to 200 (lowest setting)

Measure between

A and B
B and C
A and C

You should have 0.1 - 1.0 ohm on each.

Next.. your battery is most likely goosed so a replacement would be well on the cards.

Make sure you have a fully charged battery and start the bike up, leaving the yellow plug disconnected (make sure your lights are off for this)

Set the multimeter to AC volts.. 200/250 setting if it's manual.

Hold the RPM at 5000 and test the same pairs of wires listed above.. you should have around 50v on each pair.

If all these are ok then your stator is most likely ok.

The best reg/rec to fit is one from a 1999 - 2005 R6 Yamaha.. you'll need to cut the plug off and solder spade connectors on but a 2nd hand one can be had for around 25gbp and there bullet proof.

Also.. they never came in repsol colours so it's had a respary, probably due to crash damage.. check everythings straight and true.

The rear wheel bearings are expensive and often overlooked when greasing for services so check them.

Carbs often have bits mixed up and incorrectly set, so when it's running if it's not idling smooth or fails to pick up well when warm first port of call is to strip and check carbs, adjust valve clearances and balance carbs. Should run really smooth.

The collectorbox is a weak point.. if they rust and rot away as most do its' an engine out job and 300+ to replace.

Front forks are typical 80's Honda so very soft... if your a heavier rider some new springs will make a world of difference.

The front brakes are 2 piston sliding types.. these are also often neglected.. a good overhauled set with new rubber grommets and seals and proper grease will work well.. a neglected set with swollen seals and stuck sliders will perform poorly.

There not a bad old bike.. typical 80's Honda ride.. also don't fetch much money due to the overwhelming popularity of the NC30 which had better brakes, tyre choices, frame etc.

Still, there a decent cheap old bike with a reliable motor, hopefully it's not been neglected too badly and won't turn into a money pit.

Welcome to the forum, if theres anything else you need to know about them just reply!

[Utopic]

Wow thanks for the wealth of information!! I know that the CDI got fried cos when I opened it there was a big black gaping hole where a capacitor once sat!! The replacement is an original of a bike that was stripped for spares from a local and might I add reputible bike shop. Ok befor I can do all of the tests for the stators I need to figure out how to wire up the solenoid. I have a red/yellow wire, 2 green/red (that were together befor the crimp blew apart) a red/white and a plain red.

Pertaining to the engine I have been led to believe that everything works extremely well and I trust the guy. Checked her for accident damage and everything seems good. The forks do seem a little soft but I'm a really light person so don't think I'll have any problems just yet. My main aim for the time being is to get the electrics sorted and then I can start tinkering with the engine, suspension and body work.

[Utopic]

Oh yea the exhaust and collection box have been completely overhauled. In fact it looks as if the whole lot have been recently fabricated because there isn't a spot of rust on em at all!!

Pertaining to the battery when I removed it, it tested 12.59V and looks to be in good nick so I doubt it poked but I'll maybe get another just in case. God knows I've had bettery problems with every car or bike I've ever owned!! Must be a curse lol!

[Neosophist]

Wow that sounds like a major fault!

I'd leave the ECU off and connect up the solenoid and turn it on to make sure it doesn't go bang again.

Sounds as if fuse was bypassed and probably battery connected wrong way.. lets hope too much else isn't fried.

Might be worth getting a new loom.. I actually have a spare but it's miles away i'm afriad.

It's not difficult to wire up.

You have 4 wires that goto the plug.. there are two of each.

I'll have to check the wiring diagram or get somebody to take you a picture.. you can use Spade connectors but make sure they are insulated so they CANNOT touch and are SOLDERED.. they carry high current.

Put a 30amp fuse in the solenoid.. connect the plug and the wires to the solenoid.

[Utopic]

Yea thanks for that everything has been sorted. Would it be viable to mount the regulator ont the side of the chassis?? I've heard this is a good way to keep it cool.

When you say you're miles away what does that mean?? I'm comtemplating getting a replacement loom cos the one on my bike is looking quite tacky.

[Neosophist]

Yea thanks for that everything has been sorted. Would it be viable to mount the regulator ont the side of the chassis?? I've heard this is a good way to keep it cool.

When you say you're miles away what does that mean?? I'm comtemplating getting a replacement loom cos the one on my bike is looking quite tacky.

I live in Japan but the spare loom I have is in the UK somewhere.

As long as it's working the current loom should suffice until all the other problems have been sorted.

You could mount the reg/rec on the subframe.. there are two rear triangles.. I welded some 2mm steel to one of mine to make a plate to mount the reg/rec.

[Utopic]

Ok cool I think I'll do that!! Looking forward to my ride later :D