PW50 spark problem

temppp
Posts
36
Joined
10/16/2016
Location
AU
I've had other posts on here about this bike but the basic story is that the bike ran (with other issues) and then after installing a new complete top end I can't get it to produce proper spark.

I have rested the spark plug on the head and have seen what I would describe as a bright blue spark but then there will be nothing after it. I've also held a screwdriver in the spark plug cap and have felt a shock but I don't think it's ever happened more than twice (if that...) before I gave up waiting for the next spark.

I have tested the continuity of the off/run/start switch and it's correct for each setting.

Primary coil resistance: 0.32-0.48Ω
Mine likes to sit at 2.1Ω which is a bit high even if you allow for the leads. I'm only using a cheap multimeter so it might not be that accurate at low readings?

Secondary coil resistance: 5.68-8.52kΩ
This was right around 6kΩ, good.

Pick up coil resistance: 18-22Ω
20.3Ω, good

Charging coil resistance: 297-363Ω
Nothing

Lighting coil resistance: 0.57-0.69Ω
Nothing

These are from a different year model manual but I don't think they changed at all.

I also tried testing on each end of the spark plug cap but I can't get any reading for that.

Any idea why I can't get a reading for 2 of the 3 coils? Did I somehow blow both of them or am I just doing something wrong?

Is there anything else I can do or do I need to start looking for a stator to buy?

Any help is greatly appreciated.

Thanks
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Paw Paw
Posts
679
Joined
12/24/2011
Location
Benton, LA US
6/9/2017 9:48am
I would be looking for broken wires, dirty plug in connections and etc. If nothing found then maybe the stator is bad.
Have you cleaned the ignition coil mounts? They get dirty and rusty. Have you attempted to replace the spark plug cap? They do get crusty over time. Most can be unscrewed from the sparkplug wire. Then the wire can be cut back 1/4" and the plug cap reinstalled. Also be sure the engine mounts are free of rust as well.

Paw Paw
temppp
Posts
36
Joined
10/16/2016
Location
AU
6/9/2017 10:42am
Thanks for the quick reply.

One frame/coil mount is painted, so I left that. The other had some rust which I sanded off. Also cleaned up the ground wire connector. I sanded the rust off the top/bottom of the ignition coil mounts, haven't done the "outside" on them but I don't know if that matters.

I'm using 120grit sandpaper, is that fine or should I swap to something else?

Haven't tried a new spark plug cap but it's on the list to replace. Some of the plastic from it has broken away on the end where it connects to the spark plug so it's a bit dirty and/or corroded in there. Haven't cut the wire back yet.

I didn't notice any damage to the stator wires. Sounds like I might need to remove the stator and check the other end of the wires where they join the stator? Yay.

I'll take another look at it tomorrow and get back to you.

Cheers
6/9/2017 10:25pm
Have you tried to just throw a plug in it and start it up ? I have a PW80 of a friend that I am trying to sort out for him. Can hardly see a spark jumping the plug gap. But it will start and run. If it ran before, chances are ,it should run again.

I have never had to replace any ignition components on a PW50, save for a crunched up start run switch.
temppp
Posts
36
Joined
10/16/2016
Location
AU
6/10/2017 10:31am
Yeah, many attempts. After I installed the top end I put it all back together, filled the tank and tried to start it but nothing happened. Next day I checked the wires and tried to start it again, still nothing. It's getting fuel and I think the compression feels fine when I cover the spark plug hole (don't have a compression tester)

Then I got a multimeter and followed the steps to get the readings above.

The Shop

temppp
Posts
36
Joined
10/16/2016
Location
AU
6/11/2017 9:52am
Well I found the charging coil resistance but it's not where it should be, according to the manual.

(manual) Pick up coil: White/Red - Black : 18-22Ω
(mine) same wires: 20.3Ω

(manual) Charging coil: Black/Red - Black : 297-363Ω
(mine) same wires: nothing. Black/Red - White : 301Ω

(manual) Lighting coil: White - Black : 0.57-0.69Ω
(mine) nothing. Can't find this reading on any combination of the wires.

At least I'm getting something through each wire but it's still messed up. I'm quite sure that the stator wires have remained the same over the years, apart from the connectors used.

I've had the stator out before but that was months ago and the bike had been running since then.

Any ideas?
temppp
Posts
36
Joined
10/16/2016
Location
AU
7/15/2017 6:26am
Thought I would update this for anyone who might come across it when having their own problems. I believe the only problem with my bike was the spark plug cap not keeping a solid connection with the spark plug. Didn't do anything with the stator so the above numbers must be acceptable to get it running. I've had other people give me their readings and a lot of them don't match up so the values/wires must vary over the years. Cheers
lumpy790
Posts
9253
Joined
9/18/2007
Location
York, SC US
7/16/2017 9:01am
Had a problem once and it ended up being dirty inside the handlebar switch with the start mode.

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