Help, no spark: By zbuck (Read 6,986 times)

[zbuck]

Rich, checked resistance on the pickup coil. 147.3 Ohms. Trigger magnet solid in flywheel/rotor. Magnetic field strong on inside of the flywheel (stator side). But very weak magnetic pull from trigger magnet. How much height should I have on the trigger magnet from flywheel? I am thinking about buying a new flywheel, but I am trying to fiqure out the difference between a 10$ one verus a 30$ one. Don B.

[Bashan]

It turns out you have a very odd stator and that may be part of the problem. I talked with Dr. JR and he's rushing home in his truck loaded with manure to look at your problem. He at least has heard of your stator, to me it's an alien being. The tutorial you were reading in the electrical section that I posted is on my eight pole single ignition five wire: G/W/Y in the harness with a blue and red hanging seperate. This is a description from Scrappy's site:SCRAPPY DOG PARTS PAGE

Here is a pic I took of my flywheel:

Dr. JR thinks your test may be coming out wrong because of a ground difference. We'll figure it out. Rich

[zbuck]

Thank you Rich & Dr.JR for your replies. Rich,the picture that you posted for Scrappy Doc is the one I bought along with Hi-po coil and CDI from Scrappy Doc. The air gap between pickup coil and flywheel magnet checks .032 and I see no way to adjust. Dr. JR, the wire colors thats in your reply are the same on the new stator and the old stator. I guess that it could be possible that the new stators pickup coil could be bad, as the old and new there is no ACV from blue and white wire. Any more ideas/suggestions will be greatly appreciated. Don B.

[Bashan]

Oct 9, 2010 17:16:34 GMT -6 felliott said:

The setting should be from .008 to .015. I just checked one that runs and it is .018.

Oct 9, 2010 17:39:16 GMT -6 felliott said:

Up date: I just checked a new engine I have on the shelf and it checks .006

I did a lot of reading on this today and found out some interesting things. The main thing is every gap I found for the sensor was never over .02" regardless of whether it's a scooter or larger unit. So at .032, considering what felliot found and I measured, I've got to think the sensor is too far away to get a signal. Now how the gap changed, or indeed IF it changed, I have no idea. Can you measure the height of the trigger magnet on the flywheel? I'm grasping at straws though. Rich

[sprocket]

When you changed the stator is it the same number of poles as the original? I'm wondering if you are using an 8 pole stator with 6 pole flywheel...?

[zbuck]

Rich, magnet heigth .045. Sprocket, same number as the old one, 8 poles, 4 wires. With the flywheel that is orignal to the scooter. Any more ideas/suggestions? Don B.

[bige]

I had one in my shop that did the same thing, replaced all the componets with known good ones. turned out there was a ground wire in the middle of the harness that was bad

[sprocket]

Not sure if this will help...

I know of someone with the same problem.. after weeks of testing wiring it was actually a short in the kill switch...every so often the switch decided to shut the bike down...

One of the large problems on these scooters is they often use lead acid core plumbers solder, to make the connections in the harness. Probably more available and cheaper in China than rosin core, but it will corrode the copper wires within a year or so...

It is easy to test, just wet the solder connection with with a damp finger and then taste it. If it tastes like acid (lemon) then it is acid core solder and all the connections should be re-worked...

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[zbuck]

Thanks for the replies guys. bige, I am going to go thru the wiring again. I have four grounds on the scooter, three I added from the battery negative side. sprocket, I am going to recheck the kill and igntion switches. You are right about the wire connectors, Chinese junk I have replaced about 90% with USA connectors and as far as I can tell they used acid core solder and they did not do a very good job at that. Don B.

[zbuck]

Update, it lives again. Went over the wiring again, nothing wrong. Pulled new stator to check continuity on bl/w wire, none, bad connection, repaired. New hi-po coil, spark plug fell out of boot, connection in the boot(bakealite part) was so loose could not hold spark plug, used boot from old coil , good connection. New plug and were running. I guess I should have bought a better grade of Hi-po stuff. Oh well live and learn. Thank you guys for all your help. Don B.

[Bashan]

Man, what a journey, kudos to you for sticking it out and figuring it out. Well we learned the airgap isn't all that critical but the blue wire does have to be connected from beginning to end. Those coils and plug boots can be a real problem, they look OK but don't make contact sometimes. Glad you're back up and running, I guess we all learned something, that's what a forum is for. Rich

[zbuck]

Yes, I very much learned something trying to figure this problem out. But cold staring this scooter is a trip. You have to prime the heck out of the carb. But once it starts and warms up a little it is fine. All kinds of power and it has a 72cc kit in it with modded exhaust and a UNI filter. Grandson stated, that I should start a scooter repair shop, my answer, there is no freakin way. Again Thank you everyone for all the help. Don B.

[sprocket]

Cold start problem.. You check the enricher on the carb to see if the pin is either stuck or not operating. Sometimes it is just the enricher connection to the wiring harness... check for voltage there could be AC or DC, and probably will only register when the bike is running...

[zbuck]

Sprocket, when I put the BBK in it, I also installed new carb., with new enrichner. I will check the wiring. I might have messed up the connection when trouble shooting for the no start problem. Don B.

[sprocket]

Usually the plug on the enricher is red in colour and joins the harness under the seat tub on the right side. Check the copper spades in the connector, I have seen many of them bent and not making contact...