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Help, won't start

Posted: Thu Aug 31, 2017 8:40 pm
by SP_BOTT
This is the same bike in the project section, small intro, bought the bike as a 'seized project', stripped cleaned painted, all the usual stuff, got around to starting it the other day, (or so I thought)

Kicked away for 1/2 a day and decided it wasn't going for it. Found out the stator has burnt out, had a spare that tested ok according to manual/this site. fitted it and still no good.

new BR9 iridium plugs fitted, not starting.

Changed pick up coil and reset gap to 0.6mm - not starting.

Checked and shorted all switches, sidestand, clutch, off/run. - nope.

wheeled back in garage and did have fat spark (so something suggests an intermittent fault???) but today when checked nothing all day,

also had carbs off, reset floats/air screws just to be sure.

Have also swapped diode and the rectifier, and also swapped the CDI a couple of times just in case.
Had a meter on everything I can think of. Exciter coils and generator all test ok.

Had my meter on the primary coil, and getting no voltage on this when kicking (can this be checked?)

I do have fitted a 0.5 Ohm dyna coil, replaced leads on this too as fitments are a bit poor/tight. Standard coil tests out as open circuit on HT side.

Sorry it's a bit long winded, but at my wits end, and can't think of anything else, so open to suggestions please :)

Re: Help, won't start

Posted: Thu Aug 31, 2017 9:53 pm
by Binetta Steve
I know KR's are magneto type start but what sort of condition is your battery?

I found the side stand didnt inhibit starting it just made the KR misfire.

What would cause an intermittent " fat spark" , does this hold a clue?

Sorry not helping just thinking it through.

Re: Help, won't start

Posted: Thu Aug 31, 2017 10:52 pm
by JanBros
do youur plugs get wet ? do you smell gas at the pipes ? maybe carnk seals are gone and there is no mixture going through the engine..

Re: Help, won't start

Posted: Fri Sep 01, 2017 8:10 am
by SP_BOTT
Thanks, battery is good, still at 11.8v after a couple of days trying, might try another genny/alternaor off my good bike. Plugs are getting wet with fueal, as removed and checked after doing the carbs a couple of times.

I'm thinking elect, but not sure what fires LT side of coil. tried it in gear/out of gear clutch in/out sidestand up etc. Was thinking it was my dynacoil, but reads good after re doing with the new leads. Dyna is 0.5 ohm, original is 3 ohm, but manual suggests should be read less than 1ohm.

Re: Help, won't start

Posted: Fri Sep 01, 2017 4:09 pm
by Garry
I am not very good with electrics but could it be one of the following

Faulty Ignition Switch
Broken wire in the loom
Blown Fuse (not sure if this would interfere with starting)
Connector blocks not making good contact

Might not be any help so good luck :P

Re: Help, won't start

Posted: Fri Sep 01, 2017 9:29 pm
by SP_BOTT
Must admit, I haven't checked the ign switch, but it does look like a new one (different key) so worth an inspection, PV's do the 'cycle thing' when turned on and all lights etc work.

Also have a spare loom, but hopefully it's not that, as they seem quite robust when compared to LC's and that era of bike. Back on shifts now so won't get to it that much.

Re: Help, won't start

Posted: Sat Sep 02, 2017 12:37 pm
by JanBros
does it give any sign of life when kicking ?

fat spark is no good. the smaller/bluer the better.
do you have a strobe to check you have sparks when plugs are fitted ?

Re: Help, won't start

Posted: Sat Sep 02, 2017 2:27 pm
by podman
Mike (kopite30) had a similar problem and it turned out to be a magnet on the rotor was coming loose and eventually it fell off completely...worth a check anyway and good luck.

Re: Help, won't start

Posted: Sat Sep 02, 2017 8:34 pm
by SP_BOTT
Some good ideas there, Did have a spark at one point, but I had a suspician it was just on one lead/plug, hence me changing the two new leads. (have continuity through the coil now)

I do have an old strobe, somewhere, (like that idea) that's a good way of checking whilst leaving the plugs etc all fitted just in case it does stutter into life. Flywheel looks in great condition, but I will aslo recheck, as I might fit another stator I have (has slightly different resistance reading on this one, but all in spec)

Re: Help, won't start

Posted: Sat Sep 09, 2017 5:17 pm
by SP_BOTT
It's running...Yayyyy. Finally sparked into life, first kick this afternoon, had everything to bits several times over this morning, been swapping and testing everyspare I have, and tried them all, in every combination possible, also stripped the cdi and took it apart for a look.

It's running quite nicely, but much stronger on the LH pot, could be anything after a firts start, purged the oil lines, and running premix etc, roughly set the air screws, hopefully now next week whan I have a few more days off, I'll do a couple of heat cycles and tidy it all up again, as I have wires and cables/plugs hanging everywhere.

Glad to see the new Dyna coil has worked as well, so will also do a voltage check from the regulator/rectifier, as I don't want to burn the CDI out after this headache.