So I'm new here, just joined up hoping to get some help with this little quad we acquired. A friend gave it to me after his kid stopped riding it, I happen to have a 5yo nephew who is ready to ride. Basically it looks in decent shape but won't start up, it will crank but no spark. I am suspecting some sort of wiring problem as it has a few safety features that seem to be deleted(looks like a lanyard pull out safety style switch has been bypassed, also looks to have some sort of alarm?).

Anyways, here are a few pics of the machine, hopefully we can identify it or narrow it down enough to be able to work on it.

I greatly appreciate any help with this matter, I am happy to read whatever you recommend and can take readings and such with volt meter here. Let me know what I can do to help fix this thing!

Thanks very much in advance!

 

50 views and no replies? Am I doing this wrong?

I went out last night and noticed the spark plug wire seems cracked but still connected. I guess I'm gonna start by buying a generic ignition coil and cable, might buy an extra CDI unit while I am at it.

If anybody has specific ideas for me to try to pinpoint the issue I'd appreciate it greatly.

Thanks again.

 

ok, you said it cranks but no spark. that means the brake switch interlock is working. you do have the left handlebar brake handle engaged, right? next, explain the bypass on the rear tether switch. Lynn has an excellent write up on the rear tether switch, that could be the problem also. i'll peruse through the many posts that Lynn has done and post them as hyperlinks to make it easier for you to start testing.
BTW, welcome to the forums.
you've obviously pulled the spark plug and checked for spark there, right? i presume that's how you deduced that you have a no spark condition-just double checking your method with this comment.
you'll need to double check the position of the kill switch on the left handlebar. also check the wiring on the backside of the keyswitch to make sure no other wiring is grounded out, either by a hole rubbed in the wire jacket or rubbing the ground wiring there in that area.

 

is there a VIN stamped to the lower left hand side of the frame or a metal ID tag up front on the grab handle? sometimes there may even be a sticker on the vertical tube heading up to the handlebars. i worked on a 110cc just like that one about a month ago and the name escapes me! it "might" be a zongshen?

 

Hi and thanks for the reply!

Yes it cranks but won't start. I don't think I tried pulling in the left handbrake when cranking, is this required to get spark?

I did pull the spark plug and saw no spark when I grounded it to the engine and cranked it. Again w/o the handbrake engaged.

The rear teather looks like somebody just cut the wires and butt spliced them together, it wasn't cranking like this though so I unconnected them and it would at least crank then. So right now the two wires are just loose.


I'll try it with the handbrake pulled in when I get home, maybe it's that simple but how would it keep running once the brake is released?

 

I found what looks like a VIN on the rear grab bar, it reads as:
L5NSUMC015T008758


Thanks very much for you help here, greatly appreciated!

 

Also wanted to mention that there is "YUN BA" printed on what looks like an alarm and computer box, is this specific to those components or the entire quad?

Here's what I am talking about:

 

Maybe I should also include that I did try to test the kill switches last night. I basically took the CDI box off of the plug and checked for the presence of a connection to ground on the lower middle pin of the connector(black w white stripe). At first it grounded, then I pulled apart the tether wires and turned the key to the ON position, after that it reads 0.00. So I think the kill switches are OK.

Maybe I did the test wrong or maybe it has nothing to do with my problem, I don't really know at this point. I have found a lot of similar threads and just trying to make sense out of all the various information. I am normally pretty good about figuring this stuff out but without even knowing what make/model it is I am at a bit of a loss.

 

sorry i got my cart before my horse, the brake switch interlock has to be satisfied in order for the quad to crank/turn over. rear tether kill switch may be suspect, but if you got the wires separated, that should do it. have you traced the wiring and looked for burn/hot spots,kinked wires, and other suspect wiring that may be deficient in and around the CDI and towards the regulator?

 

i know nothing about those alarms. we'll have to find some of Lynn's write ups about that.