I recently picked up a used Roketa 110cc quad (circa 2008) for the kids to play with.

Day 1: Would start with a click of the starter button. Half an engine turn, max. Pretty slick.

Day 2: Would not start. Daggonit, I guess I should have charged the battery overnight. I charged the battery and it would turn over two or three times and then stop turning. After several attempts it started up just like day one, half a turn on the engine and its alive. Weird.

Day 3: Same problem as day two. Will start eventually, but wouldn't start a second time. Recharged the battery again.

Then I tore into it.

I found:

1: Loose wiring everywhere (chinese quality I guess). I replaced a lot of the connectors and soldered a few joints.

2. The hot wire (red) from the battery to the coil gets really hot following a cranking session.

3. The hot wire leading into the coil got so hot it melted a bit of the plastic wrapping. I cut out the bad section and rewired the connector.

4. Pulled the starter (figured maybe with was causing the heavy draw). Took it apart and found no carbon build up, turns easily, tested without a load and turns indefinitely with starter switch depression.

5. Battery is holding 12-13 volts. Same at the coil. During a start it drops to 8 volts.

So, is it the battery? Is it wiring faults? Is it the starter?

Appreciate any insight.

Thanks,
- Pete

 

I'm a bit confused... See some comments below...

What exactly is this "hot wire from the battery to the coil"? When people say "coil" they often mean "ignition coil". But there certainly should *not* be a 12 volt wire to the ignition coil. That would burn up the coil, and make all the wires feeding it hot (and blow the fuse too if it hasn't been bypassed). For some reason a lot of people think there should be 12 volts at the ignition coil. Perhaps this misconception dates back to the old Kettering style ignition (points, plug and condensor) from the 1960's, but on CDI systems there isn't 12 volt anything at the ignition coil input. It is moderately high voltage (a couple hundred volts), high frequency pulses. That's it. No 12 volts .

By chance did you mean the fat heavy wire from the battery to the starter solenoid? This would be to a screw terminal on the solenoid, and there would be another fat red wire from a second screw post on the solenoid down to the starter motor.

When you say connector I hope you don't mean a real connector with small pins housed in a plastic shroud. If so we're way off base since there should be no connectors on the way to the starter motor. They just wouldn't be able to handle that kind of current. There are ring terminals (or screw lugs if you prefer) on the way from the battery to the starter motor, but they are large crimp terminations each on a single wire.

Does this red wire that gets hot "leading to the coil" (I hope that means starter solenoid) get uniformly hot over it's entire length? Or does just a single joint or piece get hot?

Again I hope you don't mean the ignition coil. If it is at the starter solenoid then OK. But then you say that during a start the voltage drops to 8 volts? Where did you measure this? Did you have the probes right on the battery terminals (plus and minus), or were you measuring somewhere else? Please be specific - this is important data.

If you are really talking the starter solenoid then I think this will be an easy problem to solve with a meter. Some of the answers above will get us pointed in the right direction.

 

Yes, I mean starter solenoid (sorry for the confusion).

Both battery wires get hot during start attempts. The starter turns the engine over a couple of turns and hangs. Taillight fades and wire leads get hot. Can repeat several times until battery looses charge.

I replaced the battery yesterday. Same symptoms.

Ordered a new starter last night.

 

Phew...

What you're looking for here is symmetry. All the wires going to and from the starter should be uniformly hot. The idea here is that the wire gauge for the starter feed wires, and the ground return wires are the same. So they should act and exhibit symptoms the same because the exact same current is flowing though the entire path. Ditto for all the terminal connections. They should all be the same temperature right after a stalled starter motor scenario. If any one section of wire, or terminal joint stands out above the rest that is a big red flag that indicates a problem right where the heat is greatest. But this does not sound like your problem....

I think a bad starter is a real possibility. An engine that is too hard to turn is another less likely possibility. You can try grabbing a hold of a nut on the crankshaft and see if the motor will turn. If the motor turns OK the starter motor is the most likely fault where starter wires get uniformly hot over their entire length (indicating starter is drawing way too much current).

In the meantime keep that new battery charged up with a maintenance charger. Batteries that sit around discharged get ruined quickly.

 

I've had this type thing on several of my quads/3-wheelers when I buy them. Here's what I've found to fix it.

-As Lynn states, batteries drain from long term sitting and then won't hold coltage when a load is put on it when starting. I've installed trickle charger/maintainers on all my OHV's/mowers, etc and that solved that. They self adjust to what the battery requires and woll not overcharge the battery

- Next item would be disconnecting the battery leads, solenoid leads, starter lead and wire brush them all. Dirt/corrosion build up no matter how slight looking to the eye will cause you to lose good current flow.

-Another thing I've done to help narrow things down was to take a good fully charged battery (I have a spare I keep handy) and connect it directly to the starter (or starter solenoid) and see how it turns over. This not only helps narrow down where the problem may be, but also if it's a component (solenoid, starter, etc) or wiring.

Let us konw how it turns out and good luck.

 

I replaced the battery. Didn't fix it. Figured it was the battery or the starter. Put an order in on ebay for a the starter ($22 shipped).

Popped the starter in and viola - back in business. Twas the starter.

Thanks for the help guys.

- Pete

 

I'm glad you got it back up and running...