Howdy do,

I recently bought a VFR400k NC21 all was happy and running well until i Jet washed it yesterday.

It was running fine and then slowly started to Die, it eventually cut out and wouldn't start. So i left it over night t dry out and came back to it today. It was a nice day so i stripped It down cleaned all the plugs and sprayed with GT85 and tried to get her running again. It was turning over but not firing, so I stripped it down once more, taking the Spark plugs out and cleaning them up and trying to turn it over checking for spark.

To which there wasnt any, and I thought about the rectifier. After a few more hours of tinkering and drying the water out i built it all back up, turned the key and Nothing happened. The CDI usually clicks and a little OIL light pops up, but this was as if there wasn't a battery connected.

The battery is brand new and I'm thinking I may of blown the Rectifier and/OR the CDI so I've ordered a new one of each hoping this will solve the problem.

Is there anything else i may of done in the process of washing the bloody thing?

Gareth.

Why take two stabs in the dark and spend money on a rect/reg and ignition unit when you have no idea what is wrong and have not waited for an answer to your request for assistance.

Not aware of any CDI that clicks when the ignition is turned, why not check the fuses, including the MAIN fuse in the starter relay, if it acts like the battery is not connected? Then you could check the battery signal into and out of the ignition switch and on down the wiring loom looking for the point at which it stops.

i had similar symptoms when the main fuse went (NC35).

the reason it went was the reg/rec as it happens, check the fuses though

magg wrote:Why take two stabs in the dark and spend money on a rect/reg and ignition unit when you have no idea what is wrong and have not waited for an answer to your request for assistance.

Not aware of any CDI that clicks when the ignition is turned, why not check the fuses, including the MAIN fuse in the starter relay, if it acts like the battery is not connected? Then you could check the battery signal into and out of the ignition switch and on down the wiring loom looking for the point at which it stops.

Stabbing in the dark makes things more interesting. To be honest, there are a few things you learn from playing with cars bikes etc for almost 20 years... If your going to try and repair something ordered all the parts you think you will need in advance and then you can crack on with the job at hand instead of waiting around for parts being delivered.

I've checked all fuses, Ive checked all terminals and connections, I've dried cleaned and sanded all the earths. I wire brushed all the parts I could to ensure a good connection was made.

In honesty, I personally think its the Starter relay which again is on order along with the Reg. I'll fit the Relay and see how we go. Fingers crossed i will manage to get a spark to the plugs.

I had no idea how flimsy and weak the electrical system was on these things, its a bit of a joke that it cant handle water without breaking. It makes me think i have chosen the wrong bike to race as i'll be a little apprehensive about racing in the rain as it might not make it into the next round. I'll see what happens.

Cheers for you help and you too DGUNTHOR.

If i get it running again I'll be happy if not i'll bang it back on ebay as a non runner and get an NC30 like i should of done in the first place hahaha.

GarethW wrote:
Stabbing in the dark makes things more interesting. To be honest, there are a few things you learn from playing with cars bikes etc for almost 20 years... If your going to try and repair something ordered all the parts you think you will need in advance and then you can crack on with the job at hand instead of waiting around for parts being delivered.

I've checked all fuses, Ive checked all terminals and connections, I've dried cleaned and sanded all the earths. I wire brushed all the parts I could to ensure a good connection was made.

In honesty, I personally think its the Starter relay which again is on order along with the Reg. I'll fit the Relay and see how we go. Fingers crossed i will manage to get a spark to the plugs.

I had no idea how flimsy and weak the electrical system was on these things, its a bit of a joke that it cant handle water without breaking. It makes me think i have chosen the wrong bike to race as i'll be a little apprehensive about racing in the rain as it might not make it into the next round. I'll see what happens.

Cheers for you help and you too DGUNTHOR.

If i get it running again I'll be happy if not i'll bang it back on ebay as a non runner and get an NC30 like i should of done in the first place hahaha.

I completely disagree with pretty much everything you have written above.

There is a hell of a lot of difference between rain and a high pressure jet washer (which you will find most manufacturers advise against using.) Give me a pressure washer and I can probably kill most bikes and cars ever made by spraying water under high pressure in the right places, not to mention ruin all the bearings too.

Myself included members on here have ridden thousands of miles in many different countries in some really tropical rain storms without issue.

Stabbing in the dark doesn't make things more interesitng, it takes more time and money and you risk breaking other things in the process, imagine if your doctor took this approach during surgery.

It would seem you don't learn much after 20 years with this stabbing in the dark approach, as the starter relay has nothing at all to do with spark to the spark plugs. It's a magnetic switch that engages the starter motor when you press the starter button. If the engine cranks but has no spark your starter relay is working. If the bike is totally dead this doesn't mean your starter relay is broken.

Also, you can run the bike without a regulator even fitted and it will still work... so no need to buy one of those unless you can run the bike and then perform the tests on it to determine if it works or not.

I can't even understand the current state of play with the bike from your vague description.

It started to stutter and misfire and then died? Did it crank over after that but not fire up or did it just cut out and not crank again? Any electrical signs of life like cranking?

I understand that after this you stripped it down and found no spark? so it cranked? but then you started "stabbing about" and now it doesnt work at all, as in it looks totally dead?

Which fuses have you checked.. there is a main master fuse as magg has pointed out hiding in the starter relay by the battery, if you shorted somethign big this will pop. its pretty much the only thing that should stop the oil pressure light coming on when you turn the key.

" If your going to try and repair something ordered all the parts you think you will need in advance and then you can crack on with the job at hand instead of waiting around for parts being delivered."

From what you have described so far your fault could be anything from water in the carbs, a shorted out electrical connection, blown fuse, fried ignitino box.

You do not simply blindly order all those parts, which range from about 20p for a fuse to a hundred pounds or more for the ignition box, when it might not even need any parts at all.

I can see why you are blaming the bike when you don't really seem to understand what is going on or how to fix it.

With the vast amount of knowledge on here, and in the service books and other documentation, a little methodical approach and diagnosis will help you find the cause of your problem

Sanding earth tags after washing the bike to try and fix the problem is like doing a dance to make it rain.

with your current attitude I don't think you will fair any better with an NC30 as apart form having different suspension and forks the engine is very similar apart from the actual crankshaft, as is the electrical system.

take a methodical approach to solving the issue with the bike and with help from people on here like magg etc you will get it working in no time, probably spending as little as possible.

But in terms of replacing it for an nc30, you would probably have more problems as the nc30s have always been more desirable and more abused becuase of it so often developing more problems.

Thanks for the Advice.

To be fair I wasn't in the best mood or frame of mind when I posted this, which is to be expected after ruining your bike and I presume my wording and description/argumentative tone has left me looking like a bit of a cock and has got me nowhere in the process of fixing it.

In hindsight, I should of taken the time and effort to clean the bike by hand, but I didn't and have effectively made my bed, so one shall now sleep in it.

To be honest, I agree with most of your comments and I should of attacked the bikes problems in a systematic manor, starting with the basics etc. Instead, I've left myself with no real starting point and a messy electrical system.

Current State of play is:

Stripped down to bare essentials, all fuses are in tact and have been cleaned to ensure a good connection.

The Starter relay poles had been stripped (threads so this could of added to the problem) and so a replacement was ordered.

All connector blocks and wiring connections have been cleaned and dried (I was going to use a silicon grease once it is running to aid in the protection of the wires, I am still researching the effects of this.)

There are No ignition lights at the moment

Battery is brand new and currently being maintained by a trickle charger.

Earthing points have been cleaned

coil pack spade terminals have been cleaned and cheeked for breakage in the wires all four seem to be in good condition (visually)

Starter motor is fine and will turn the engine over.

Plugs are fresh and clean using the standard gapping


The problems arose from washing the bike as stated, It turned over and started on the choke with no issues. It Ran for around 5 mins after that time I backed the choke off and it cut out. From that point it would crank, but not start.

I left it until the following day checked over the fuses which were all fine and the visible wiring plugs were disconnected and dried.

Once I had gone over most of the bike checking the wiring plugs etc and it still wouldn't start I pulled the plugs which were wet with fuel, I cleaned and dried them and then cranked the bike over testing it was getting spark. At this point it wasn't.

One thing I did notice was a clicking noise from the back of the bike when the ignition key was turned, this stopped around the same time the ignition refused to work.

There are two relays at the back of the bike along with a black box next to the rectifier which I'm a little unsure about (any ideas)?

The Neutral switch is faulty, but this is bypassed with the clutch switch but that wouldn't stop the ignition lights/oil pressure light showing once the key is turned.

Like you say, and I agree i May of totally fried one of the main electrical components. I will get her going again, its just a matter of time now and a fresh outlook which i now have as I'm back on my medication :D

Probably me too, but at least there is a nice good description up now of your current state of play, with the knowledge on board im sure you'll get it sorted.

The 400K was a training school bike so perhaps its wired up differently to a stock NC21. Being nearly 30 years old and a grey import it could have had any number of wiring loom hacks done to it.

If you heard a clicking before when you turend the key this sounds like some kind of relay was switching on and off via the key. Have you checked for any relays on the loom and made sure their contacts are ok? you can actually test relays with 12v from the battery if you know the pinout.

Have you checked the main fuse in the starter relay? Its separete to the fuses in the fusebox.

It cranks now but you have no lights? or it doesn't crank at all?

If it cranks and you dont have anything thats very interesting (at least to me!) ill try and dig up an vfr400k wiring diagram. If its just totally dead then probably main fuse or connection or somethign simple.

If its cranking and no lights on the dash then you have no power to the dash and probably coils, hence the no spark.

The relays and igntion box sound interesintg, any chance of a picture? also the ignition box on the 21 is usualy by the battery. have you checked this too?

from the sound of it could just be as simple as a relay stopped working that switches the loom on.

but if that relay is controlled by the ignition box and its died then thats the issue hmm

lets get it sorted!

Finally a little progress, the vfr now has ignition and will crank over.

I left it at that today as I had to get home and see the the little one, I stripped the full loom off the bike and found a broken wire and a sneaky connection which was poor.

Next step now is to get her running again.

good good.

you have spark?

I do indeed, I had it running for a few mins and then turned it off. I can carry on with it now woo :)

Cheers for your help pal.