KR-1S.co.uk Forum

Hi everybody i just got my kr1s and have discovered that my head lamp is shite. very weak and when i break it gets brighter any suggestions cheers

check the earth to the frame...but mine has dimmed the head light when you brake or switch on an indicator(it flashes at the same rate).for years with no apparent cause(good battery,good earth,corect bulb)..not a lot but noticeable....crap electrical system...

I also have this strange problem with my 1989 KR1. Headlight gets brigher when I brake (and rubbish at idle as battery low on charge). Also noticed the indicators flash faster the higher the engine revs. Engine also running like sh*te and reluctant to pull cleanly or go above 7K. It was this sick when I bought it, and thought it was due to having seized KIPS valves. Now just finished a full top end rebuild, new KIPS valves, seals, rings, small ends etc and it is still running same sick symtoms. Cleaned tank and carbs out. Checked every jet. Dropped needles (as everyone seems to advise) and still no luck. Now thinking it is regulator/rectifier, or could it just be a cra@p battery making everything go screwy?

Let me guess, the exhausts are blocked up with carbon (the only think left to do unless it is electrical gremlins - which always do my head in...)

Any one else experienced the above?

Sounds like a crap earth to me.

Check all the little tags on the frame for corrosion and that the wires are intact.

If you have a meter, measure the battery voltage when the bike is running (about 3000rpm should be ok) and then check the supply voltage to the cdi box. You will need the wiring diagram for this but it is in the manual. If they are the same then it sounds like a coil not functioning. If there is a big difference then I'm afraid it's electrical gremlins and a bunch of fault finding. Could be crap in any one of the connectors. To measure the voltage at the cdi you need a couple of paperclips pushed into the back of the connector where the wire goes in. Might take a couple of goes to make a connection. I suggest getting a helper, you will need about 4 hands to do it all....

Cheers for the advice. I will try all of the above and get back to you. Hopefully, it is just a duff earth.

Hi Cexley,

Does the battery hold its charge? Is it a fairly new battery?
I would check the rectifier but I would check the alternator & flywheel first just to make sure its actually pumping enough leccy back to the battery & there are no probs with the windings.

When I removed the flywheel from my engine rebuild, I noticed the magnets were starting to break up (quite common on some Kwak models, IE my GPZ500 & my KE175 both have this prob).

Poor running at high speed can also be attributed to lack of leccy but also I would test the ignition coils.

Hope this helps?

Howie

I woul also check earth first, it's crappy on most bikes, even more modern ones, as it is usually more or less 'left to chance' when they assemble them at the factory...

having said that, there's going to be some kinks in a twenty year old electrical system. What mine does is the brake light comes on when I switch on the ignition, and curiously doesn't switch off even if the ignition goes off. I checked some of the connections etc and the bloke who sold me the bike basically was an utter moron who didn't take care of it at all. Lots and lots of frayed wires is what I found, I wouldn't dare ride the bike in the rain for fear of being electrocuted.

Well I am losing the plot now. Checked, cleaned and reset earth connectors. I could only find 2. One from the Rectifier/Regulator and the inevitable one from the neg battery. Are there any others I have missed? Wiring diagram only shows these 2 main earth points.

Bought a new battery and plugs today (just to eliminate them from the enquiry). Put a meter across the battery and voltage stayed constant when reving the engine. I guess this was because the battery was new and fully charged?.... Should I have seen an increase in current?

I have just spent this evening with a blowtorch and my daughter's hair drier setting fire to the spannies. Get them red hot and then use hair dryer to create a blast furnace inside the pipe. The bright red inferno works its way up the pipe and burns out the oil and carbon. If this doesn't solve this PITA problem, then it has to be electrics - which I hate.

I don't have a puller to get the flywheel off and I don't really understand what goes on in the CDI etc. Any tips to help me isolate which box of tricks has failed would be greatly appreciated.

Battery voltage always being the same points to one of two things, the rectifier or the generator.

First thing check your fuses are ok, the feed to the battery from the reg/rec goes through the 20 amp one to get to the battery. A white wire goes from the reg to the fuse and a white/red comes out to the battery. You should check this wire is ok too by unplugging the reg and sticking the meter on 'ping' from the white terminal on the plug to the positive wire on the battery. On my bike there was a bullet connector in the wire near the battery, that small bullet connector was corroded to buggery, all the copper has dissolved in the wire and although it showed continuity it could not carry any current, so bugger all worked without the engine running, except the headlight which was bright.....

The other output from the reg (brown wire) goes and does all the other stuff, powering the cdi, lights etc. While you are by the reg, just check that the earth wire form the frame is actually a wire not a piece of plastic tube masquerading as one. The brown wire is more difficult to check, because it goes off to a bunch of places. So we will leave that for a moment.

Next up is check the generator is working. First resistance, check between the 3 yellow wires, between any 2 of them you should see between 0.3 and 1.0 ohm, if they are outside this then the generator rotor has to come off. Check all three 'pairs'. If one is very different to the others, or any are outside the range, then the generator is buggered

Plug it all back together and with the trusty paper clips (be very careful here do not short the two clips together, you will kill the rotor in very short order) measure the voltage across the pairs of yellow wires. You should see more than 25volts at 4000rpm. Oh have the meter on AC volts, otherwise you will think it is broken and it isn't....

As you are by the plug, turn back to DC volts and measure between the earth point and the white wire and then the brown wire, you should see this voltage get up around the 14volts mark when you rev it on the white one and the brown should be clipped to 12.5 or so. (the white is unregulated, the brown is regulated). If they don't and everything else was ok, the reg is buggered. From what you say in your post I would say the reg is the most likely problem, but doing the simple checks first means you haven't spent any money until you are sure.

There are a bunch of other things that can affect the running, the diode pack can fail and this allows the back emf from the sensor coils into the cdi box which stops it working properly, and then stops it completely.

I don't think you have this issue, because of the battery voltage issue. However if the reg/rec and the wires prove ok, then it will involve further checking.

See how you get on with the generator first.

Oh get a puller, beg borrow or steal one because the rotors weld themselves to the crank, and no amount of hitting, swearing or bodging will get them off. Even with a puller they can be right tricky little bleeders, you may need the trusty blow torch, but only near the puller, not by the magnets.... (The magnets crack very easily, and then the generator does not work properly.) I did take one apart which had about a half of one magnet left.....

You can get them from most bike shops and certainly from M&P or whatever they call themselves these days, and they aren't that expensive. Remember to remove the bolt first. I watched a mate of mine try and pull his off with the bolt in place, still tightened up

After a while I asked why and he said he didn't want to damage the threads....

Electrical stuff is a right pain to isolate & the list of things to check is endless

Given the problems you have & that you have now changed the battery, you need to check that the alternator is pumping leccy back to the rectifier/regulator. Without looking, I'm assuming the manual gives the info you will need & you WILL NEED THIS INFO!!! I am also hoping the manual with give you the specific testing procedure because it is long winded affair & I do recommend the use of beer & tabs when testing electrics (although the manual will not state this).

Fair play on setting light to the pipes I hate that job, so I just use caustic soda nowadays, its evil stuff Ha ha ha, if you use it just make sure it doesn't come into contact with aluminium, clothing, skin, pets, children, blah blah blah.

If you need any specific info about testing let me know (I owe you one for the dowels) & I'll track it down for you.

Howie

Wow, loads of advice on the black art of electrickery. I will work through all of the above and get back to you.

Apart from smoking out the neighborhood, burning out the spannies didn't produce a big pile of carbon (which I was hoping for) so apart from burning off the oil (mainly from it running sick) they were pretty clean, so engine wasn't sick due to too much back pressure or reduced diameter on tail pipes etc.

Thanks for all your help. I will give it a go tomorrow and try not fry anything expensive.

Howie wrote: Fair play on setting light to the pipes I hate that job, so I just use caustic soda nowadays, its evil stuff Ha ha ha, if you use it just make sure it doesn't come into contact with aluminium, clothing, skin, pets, children, blah blah blah.
Howie

Ah the joys of caustic soda... Mixed with sugar, pulped bog roll and water in the right quantities to form a paste, it makes a very good low power explosive.... Cheap too......

Never tried the 'blast furnace' cleaning job, always used soda.

Trouble with beer is there is always one faulty can which causes you to let the magic smoke out of whatever it is you are testing. Don't know about you but I've never managed to put that stuff back in.....

Well.... I have done all of the above and the tests in the manual. So far:

New Battery - Old one looked like it had been boiled as various cells almost dried out when I got it.
Checked earth connections - OK
Checked fuse connections - White to Red/White fuse holder a bit corroded
Checked resistance and voltage from Generator yellow connectors - OK
Checked resistance on rectifier diodes - OK
Checked generator AC output - OK

Only thing I couldn't check was the regulator (needs a load of batteries connected in series etc), the CDI and the ignition coils.

Blow torched the spannies from both ends as the engine feels like it is being choked when it tries to rev out.

Just put it all together and went for test ride in the pi$$ing rain (will it ever stop?). Anyway it was a lot better. All the lights, indicators etc behaved normally with slight dipping of headlight at idle and steady headlight strength at all revs. The indicators also flash 'normally'. They were flashing faster and faster the higher the revs and the headlight went bright when I put the brakes on (weird).

From an electrical viewpoint, all is normal. However, although better, the engine still won't pull cleanly thtough the revs. It feels like it is holding back. Occasionally it will all chime in and the show starts to take off like a 2-stroke should, then it goes off song and starts bog down. It feels like the ignition timing is randomly retarding the ignition.

I need help. This is now turning into some sort of forensic exercise! Is it the CDI or coils?

Cexley wrote:However, although better, the engine still won't pull cleanly thtough the revs. It feels like it is holding back. Occasionally it will all chime in and the show starts to take off like a 2-stroke should, then it goes off song and starts bog down. It feels like the ignition timing is randomly retarding the ignition.

If your ignition is randomly retarding as you suspect, then make sure you flywheel is tight. A few guys on here have had this come loose recently, and since it is what triggers the ignition pickup, this could be the problem.