Motoplat issue

I have a 1983 430 wr with a motoplat ignition for the first 15 rotations of the flywheel i get a weak spark then nothing let it sit for a minute or two then the same

hi to europe !

supprime kill button !
look rust at ignition coil !
change spark plug !
change spark plug protector !
look key at flywell !
CONTROLE IGNITION COIL !
CONTROLE STATOR !

1 control ignition coil picture 1
2 control stator picture 2
cable blue and and frame =180/200 ohms =good
cable blue and black = 18/20 ohms !good !

Send it Vance Smith... email offline and I will get his number for you... GREAT guy!!

This is after i had the stator rebuilt re-wound, new trigger coil, new wires and plug cap person who did the work said upper coil was good. Could not kick start it but jumped it it ran for about 2 minutes then fouled plug then very weak spark after with only a very small plug gap do i get a spark?

This is such a good forum.... Just when I thought I had a problem that nobody else had I find something very similar...

This is what happened to me the weekend when at Farleigh Castle....

Been having having a problem where the engine would just die.. I thought I had cured it but it raised it's ugly head again....

1. I put a brand new plug in for the weekend racing
2. Saturday practice - no issues started and ran sweet
3. Saturday first race - no issues (apart from me stalling it) ran sweet
4. Saturday second race - Started in the pit box ran for about 30 secs then died... could not bump start it either

Took the long walk back to my tent...

Found there was no spark at all now coming from the Motoplat unit. I then spent 2 and half hours changing the Motoplat for a SEM unit which I just happened to have with me. I don't think we had the timing quite right as it kicked back on everal occasions but it did run. Got ready for the last race and fired her up and just put on my helmet when it died again. This time after kicking and several short busrts of life the Kick start gave up so I decided that I would call it a day.

I will test the Motoplat as per Visiteur1948 suggestion and set up the SEM properly. I am also looking at a new iginition system... but they are expensive but then again going to events and only doing one race is expensive and no fun...

Stu

two pictures for you husky37
test one for ignition coil !
21.1 ohms cables blue and black
= stator OK ( 19/21 ohms standart)

test two = ligths/lamps !
cable black /yellow = 220 ohms=OK !

Thank you. I will test tomorrow.

Stu

how close do the values need to be?

Checking my ignition i have on a bike i am restoring:

Coil: 34 and 5780

Stator

26 ohm and 388

So any comments from those who know - should i be looking to replace these?

Some test procedures here:
http://www.yankeetwin.com/motoplat.html

I'm on the home stretch on my 1980 390WR restoration and tried to start it this weekend, but no luck. I think it is an ignition issue at this point. It has a 4 wire Motoplat (blue, black, yellow & white) and a red wire coil. After reviewing this thread and other related threads and trying to diagnose the problem, the following is a summary of my observations:

I have cleaned all contact points ( coil bracket to frame, frame to engine mount, engine mount to engine) to bright shiny metal and installed a serated washer under one of the head nuts. I am getting 7 ohms between the small (black) and large (blue) coil lugs and 0 ohms between the large (blue) lug and ground. I set the timing based upon the Husky manual 2 mm alignment hole in the Motoplat flywheel (I wanted to get it running before embarking on the more precise TDC timing procedure).

I am getting a consistent but weak spark. I even made a wire jumper from the coil bracket to the threaded shank of the spark plug to make sure I have a good ground, but I am still getting a consistent but weak spark.

Could it be just a bad coil based upon the above resistance results? I would prefer to stay with the Motoplat system if possible. Any tech support would be greatly appreciated.