Ignition ?

[straycat]

I've been posting on the carb thread, but am beginning to think I might have an electrical problem.
Carbs have been stripped and rebuilt as instructions. New intake o rings.

I appear to have a rich running problem but it is now happening at all throttle positions. Once I get over 4500 rpm it clears - I can open the throttle by any amount over this engine speed and I have smooth delivery. Idle has started to play up again.
I was thinking last night that this reminds me of a recent problem I had with my son's car. It would occationally blip at tickover and pull rough until I got the revs up. It turned out to be a leaking plug cap shorting on the engine. Car is only 4 years old,but French !

My bike became very poor at starting this winter ,sometimes flattening the battery 3 times befofe coughing into life. I also had an almost new plug fail. Tested voltage at coils and it was only 10.0 volts. I ran a temp cable from the battery,but bike ran no better. I have noticed a voltage dip at the battery when the coils are connected. You can see the cable arch with some load when connecting. Is this normal - condensers ?

the bike has points btw. I replaced them and condensers 3 years ago.

any thoughts ?

sc uk

[mike_of_bbg]

Please check your charging system health before going further. Have you done that?

http://www.thegsresources.com/_forum/showthread.php?p=1272192#post1272192

http://www.thegsresources.com/_forum/showthread.php?t=152769

[BassCliff]

Hi,

What cable is arcing? Have you checked and cleaned every electrical connection on the entire bike? Don't forget the fusebox and ignition switch. The coil relay mod should help.

Thank you for your indulgence,

BassCliff

[straycat]

I went through the entire charging test chart. Only thing I had was a slightly high charging voltage at the battery, but it had recently been flattened.
Looks like my stator is a replacement as all cables are yellow

If I connect the coils + 12v (or/wh) to the battery they appear to take some sort of load My battery voltage dropped from about 12.4v to 11.4 volt . I never tried it with the cables to the points disconnected,but will when I next look at it. I know the condensers store charge then the points make and discharge them to earth , could there be a slight short somewhere?
It still did this with a wire direct from battery.

sc

[hampshirehog]

Could be the condensors breaking down - one or both of them. I would replace them as a matter of course as they're so cheap. Either that or swap over to electronic ignition. I hate points now.

[straycat]

progress !

I've re checked my coil voltage. If I break the points with card, I don't get the voltage drop when ignition is on or with a direct wire from battery +12v to coils +12v. My battery voltage is probably a touch low at 12.3 volts, so I tried an overnight trickle charge, leaving the voltage at about 13.5 volts. I connected a ground negative cable from the battery to a single point on the r/r mount along with the loom ground and r/r ground cables . Did a full stator test as desribed in the stator papers. Only fault is too high a voltage at 5000rpm aproximately 17 volts. Drops to about 13-14v with lights on.

Stator has continuity of 0.75 ohms balanced
Output voltage at 5000rpm is 75-80Vac

Mine has yellow wires so I presume it's a replacement

R/R passes all the tests, but that's still where I suspect fault lies ?


Anyway , I decided to take the bike out with it's newly refreshed battery..............guess what - it never missed ! Until I put the lights on and stopped at a junction then pulled away. It did it's coughing below 4000rpm again. Switched the lights off ,rode for a while pulled up at another junction and it pulled away smoothly.

I'm going to do the coil relay mod as it was obvious I was losing at least 1volt there and I've ordered new plug caps and a set of plugs.

I can hopefully stop worrying about the carbs at least !
where do I go next ?

thanks in advance

sc

[mike_of_bbg]

If I connect the coils + 12v (or/wh) to the battery they appear to take some sort of load My battery voltage dropped from about 12.4v to 11.4 volt .

So, the load of the coils alone (no lights?) drags your battery down a whole volt? That doesn't sound like a good omen for your battery. I recently replaced mine in about that same shape or maybe even better, but I'm getting much better charging numbers out of it.

Are all 3 legs of the stator connected directly to the r/r? That's pretty common over here but our overlords decided that we shouldn't be able to turn off our headlights. One of your stator legs probably used to be switched through the headlamp switch so the r/r wouldn't have to carry that load when the lights are off. That might well explain 17V when the headlamp is off.

Is the r/r stock? Can you see what make/model it is?

[straycat]

I've just checked the wiring. The 3rd phase of the stator went out to the switchgear ,but never came back whatever position light switch was in. I 've just stripped the switch and found these contacts badly burnt. I've cleaned up the contacts and put a little tension on the springs (after I'd found them on the garage floor !) .The 3rd phase now go's to the r/r when lights are on. After checking the voltage with the lights on , I've disconnected it. Yes ,I had lights brighter than the sun at 5000rpm .

I wondered why the bike had a pack of fuses under the seat when I bought it ! The switch must have failed and that's what's stopped me blowing lamps,but not stopped frying batteries.

I followed the stator papers, but like I said earlier, I don't know what else it could be other than the r/r. It looks original to me.

sc

[Matchless]

Bypass headlight switch for the phase from the stator, by unplugging the yellow wire going to the headlight switch and directly plugging it to the R/R. This is a common modification.
First fully charge your battery and then do the stator papers test again. You will most probably find your R/R is faulty and not regulating, especially if its the original one.

[straycat]

I checked it all again . Double checked the grounding and all connections,but bike is still putting out 17-18 volts at 5000 rpm

I've finished the coil relay mod today, Fitted a new r/r ,new plugs and caps ,cleaned up my fuse box connections and redone all the grounds.

I trickle charged the battery overnight, and it was showing 13.2 volts when I disconnected it. Fitted to bike and started up. It was a bit poor on the starting,but I'm not sure if I bogged it down with too much choke,as pilot screws may be too far out now.

Checked charging at 2500 and 5000 rpm and they are now spot on as described in stator papers !

I went back to bike about 20 mins later and it wouldn't start - not even bump start. Checked battery and it's down to 11.3 volts, 11.1 after ignitiion on for about 90 seconds. I think I need a new one,as it was probably ruined by the high input voltage (?)

I never quite understood what a battery did once a bike was running ?
Does it store current to run the ignition ,lights etc. and even if you have plenty of volts out of the alternator you need amperage from the battery ?

sc