Wrong kind of spark? By mapbike (Read 5,085 times)

[mapbike]

Hello, I am new to this forum and new to scooters in general, but I have run into an issue on a 50cc Velocity 21th scooter that belongs to my younger brother and thought maybe someone here could help me to either confirm my thoughts on the problem or possibly give me another idea to consider.

:Problem: The scooter battery started running down while just sitting over night, and then after a few days the scooter started getting harder and harder to start, and then now it will not start at all, battery is on charger and spins the engine over very good but it will not start, we have checked to make sure it is getting fuel and it is, we have changed the CDI box, and replaced the ignition coil as well, we checked to see if it is getting fire to the spark plug and it is...But....! the spark that is seen as the plug is firing is bright ORANGE in color and not a good blue spark like is normaly seen, so My thoughts are that the STATOR is the problem and the reason why the spark is ORANGE and weak and may be shorted some how which is also the cause of the battery going down over night.

Has anyone else had this issue and if so do you think that my idea on the stator being the problem is possibly right based on the test I have done so far.

Sorry this is kinda long, only way I knew how to explain it all out.

Thanks in advance for any help received on this, Shan

[Bashan]

You did good, no need to apologize. You are correct, the spark should be bright blue, orange=malfunction. That would usually be the coil,but you ruled that out. Before you hit the stator swap the plug, they go bad and cause weak spark sometimes. CDI is off the table. Why is the battery going down? Is it old or do you have a short draining it, that might be the cause of the weak spark also. I'd pull some plastic and trace the wires, it's not that bad really. If all of that is good, yep, probably stator. Here's a link to a diagnostic: IGNITION DIAGNOSTICS . Hopefully some other guys will weigh in on this too.

[mapbike]

I think the battery is about 2 years old and could be bad....? as for the spark plug I used a different plug than is in it to check spark and the spark was orange just the same, like I said in earlier post I put a new CDI and a new COIL on it to see if that would affect the spark, it made no difference still had weak orange spark that is why the only other thing I could think of would be the stator, I was looking at the stator on Scrappydog's site and it does state there that the stator is a very common part to go out on the chinese scooters, that is why I thought the stator would be the next step in trying to solve the weak fire issue.
Thank you for the good advice, Shan

[mapbike]

I know for a fact the coil is not bad, I took it off my own running scooter and did the same with the CDI so I know that they are both good.

I do have a question about kickstarting the 50cc Velocity Scooter I'm messing with for my little brother though, this scooter has only got about 300 miles on it but I can reach down with my hand and spin the engine over real easy with the kickstarter and I am wondering if that is normal on the 50cc engines, because I know there is no way I could do that on my 150cc scooter, I am very concerned that it may not have enough compression to run and maybe the orange spark is not the problem and it may be something much worse that weak spark....!

[mapbike]

I put a new hotter coil and a upgraded CDI on my 150cc scooter about 2 days before I was told about the 50cc scooter having a problem, I went over to my dads house and looked it over thinking maybe it was a fuel issue, so I pulled one of the vacuum lines off the intake and sprayed a little wd-40 in it and tried to crank it, and nothing, wouldnt even try to start! I put my finger over the exhaust opening and had my dad crank it over to see if I got exhaust pressure on every stroke or on just every other stroke like it should be, it was doing as it should and I could smell the wd-40 at the tail pipe, we removed the fuel line to the carb. and cranked it over and it pumped gas so we knew we had gas getting to carb. I then remove the spark plug wire and put plug in it, grounded the plug and had it cranked over, it had what looked to be good steady spark but it was an bright orange color which in my experience is usually a cold spark that is to weak to run a small engine, that is when I desided to go and get the coil and cdi that I had just pulled off my scooter and try it out on the 50cc to see if one of those 2 items may have gone bad, after changing them out the results were the same weak orange spark and no run-E........!this is the point that I thought that the stator may be the problem, it would not keep the battery charged and may be sending such a small amount of voltage to the coil that it could not muster up a good hot spark, I would think that if the stator was only putting out a fraction of the voltage it is suppose too that the coil would not get what it needs to produce a god hot spark to the plug, that is why I had come to this conclusion.

Now on the compression topic, I can feel the compression rise as the piston reaches TDC while pushing down on the kickstarter but it seems fairly easy to push it past the compression stroke with only a slight change in resistance this is what worries me, this engine did not just quit while it was running, my dad did say that my brother told him that it seemed to have lost some power a day or so before it got to where it would not start and run after he had gone to town and shut it off, I dont know if they tried to jump it off or not I'm thinking that if they did this may have burned up a coil on the stator possibly and this may be why the spark is weak. what do you think about this?

[Alleyoop]

I think you have been fooled, "It is odd though as in my experience, a stator is either good or bad not in between but heck I've been fooled before."

Stators do get weak I think your thinking of the CDIs, they either work or not.
Alleyoop

[mapbike]

I went and looked at it again a while ago, I knew my dad had put the battery on charge and disconnected it from the scooter by removing the positive cable from battery post, this was before you guys had posted the above info. and the link for instructions on testing the stator, I took my ohm meter and did do some tests not really knowing for sure how I should be testing it....... but what I did was put my meter on DC voltage setting and then I put one probe in the red wire with black stripe and then put the black probe in the blue wire with I think a yellow stripe that come directly out of the stator wiring, I then reconnected the battery and cranked the engine over and it would show13+ volts then jump to19+ volts very irratic for about 2-3 seconds and then it would show 0 voltage from that point on, the battery had set for a couple days now after being charged up real good and seemed to have plenty of juice until I left it hooked up to the scooter for a while and then in went dead again, I went over the wiring fairly good as for what I could see and get too, cant find a short anywhere but even though the battery may be weak and need replacing it is being drained down very quick if left connected to scooter.

I'm wondering if there is a connection continually between the stator and the battery through the voltage regulator or is there a cut out between the two until the stator sends current to the regulator which in return regulates that voltage to the battery, I'm just trying to figure out if possibly the stator is where the short may be that is draining the battery or if that is even possible, I just dont know how this stuff works on these things, electrical issues are the worst for me because I am very limited in my knowledge of these systems, I know the mechanics of an engine very well been building small engines of many types for 30 years, but I have never had to trouble shoot on these types of systems before.

Thanks for the link jrryan, I will do the tests outlined on that page and see what I come up with, I have to work 12hrs a day for the next 4 days so it may be next Tuesday before I get to do the test and post my results but you guys just watch this thread and I will be back on it ASAP......!

Thank both of you both who have chimed in on this issue I appreciate it very much and I know that the info. I have been getting from you will help guide me to resolve this problem and get that little scooter on the road again.

I will still be on the forum each evening bugging you'all with other stuff, only difference is I'll be asking questions about upgrades to my scooter and not on my brothers broke one.....!

Thanks again, Shan

[mapbike]

I think you are right about the battery being weak, when hooking it up there isn't a spark I did look close and check that earlier, I will do the test on the stator and if it shows to be good based on that test then I'm not sure where I go from here on it but I may pull the flywheel cover off and check to see if maybe the key on the flywheel is sheared which I would think would throw the engine out of time and could also be something to consider, I dont know what else I would check and would think at that point that it must be an internal problem with valve train or back to the lack of enough compression for it to run. I just cant get past the bright orange spark at the plug.........this is the puzzler to me, new coil, new cdi, still weak orange spark, I just keep coming back to ignition problem or possibly timing issue..........I will know about the stator maybe tomorrow evening, even though I will be tired and it will be hot out, I will probably run over and do that test on the stator, this thing is driving me up a wall, funny things is it isnt even mine, I'm just trying to help out because I'm the only one that knows very much about it and I know very little at this point about these scooters.

Thanks Again, Shan

[fairweasel2323]

do u get arcing off the negative battery terminal I had a short like that and went all through the wiring if I had battery hooked up would just drain it ended up being the regulator just a thought from my past experience

[mapbike]

well guys I was gonna go over and do the test on the 50cc scooter this evening but it is over 100 degrees here in central texas and I left home this morning @5:10AM on my 16 mile trip to work on my scooter after only getting about 2 1/2 hours of sleep last night and I got back home this evening at 6:40PM and was just to tired to mess with it, it may be Tuesday before I get to run the test but I will get my results posted here on this thread just as soon as I know something.

Yes I am aware that the battery has nothing to do with the firing, and yes we charged the battery alone unhooked from scooter and it held a good charge for 2-3 days but when it was connected back to scooter it was dead in about 15-20 minutes, the reason I have been including both items in my questioning of the problem is because the battery started running down and the scooter was getting harder and harder to start about 2-3 days before it got to the point it is now, my brother said that it was loosing some power it seemed also, so bty this It seems that this was a problem that started small and then progressively got worse over just a few days until it would no longer start and run at all, it just seems odd that it all started with the battery not staying charged after the scooter sat for a little while and then now not only will the battery go dead after being connected the scooter after a short while but now it also has that weak orange spark at the plug and will not even try to start up, wow..... it is going to be very interesting to finally see what is causing all this mess, this bugger is really gonna be a doozy looks like.

Thanks again, Shan

[mapbike]

Thanks for the great how-to on checking for a short, I never thought of doing it that way.