I hope someone here can think of something that I haven't. I have a starting problem with my scrambler. I can pull start it, and it will start every time. If I use the starter and have my charger hooked to it, it will start about 80% of the time. The other 20% (if I don't pull start it) it will just turn over and if I quit and give it a few minutes it will usually start right up then. I unhook the charger and it might start a couple of times then no more. I pull the rope and she's running again with ease. I just don't get it. I know the battery is good, I've used several different ones that are all good, so I know that the battery isn't the problem. I've checked every connection and cleaned every connection. It seems to be charging ok when it is running.

The voltage on the battery when it is charging is around 14.5 volts When I unhook the charger the battery stays around 12.8 and will usually start. After a few cranks the battery goes to around 12.3 and it won't start anymore until I pull the rope then she fires right up. It seems to be a voltage issue. Could it possibly be the voltage regulator causing this? If not does anyone have any suggestions of what it could possibly be?

 

if your getting 14.5 volts when its on, then the reg./recifier is doing its job. i know some of the newer modles save they need at least 12.5 to 12.8 volts to start. but heres a curve ball. on my 800, i started it when i was in the votlage reading screen and noticed it dropps to 11.8 volts when i was starting it, but went right up to 14.2 when it started. so i dont know how much it really effects it except for what the books say. is the starter dragging at all. i know like on a snow blower that you can start it easier w/ the pull crank vs the electric start because the pull turns over the engine faster. just a shot in the dark.

 

Thanks for the reply.I forgot to add that the starter is new too. This is a problem I have had for a long time with this bike. I had some carb problems and while I was doing the carb work and had the plastic off I thought I would tackle this problem also while I could get to everything. So I put a new starter on it, I thought it might be the problem also. Now my carb problems are fixed and it runs great. It just won't start with the battery and has me stumped as to the reason why. It has to be voltage related because as long as the battery shows a voltage around 13 or so it will usually start.

 

i know this sounds stupid, but how are the cables and wiring? in order to carry the right amount of jucie it needs to have the right size cables or not damaged ones. and your sure you have the right stared and right battery? thats the extent of my guessing and idears. sorry.

 

Did you try a new spark plug? You could also check the coil by pulling the plug wire and put a screw driver in the boot then hold part of the screw driver near (about 3/8") the engine block. Crank the engine, if the spark is white or blue the coil is probably ok if it is yellow or orange, the coil may be weak.

What year is your bike? How many miles are on it?

 

I agree with Stendori. you know i was having the same exact thing happen but on a vehicle, and the vehicle was practically new too. checked and double check the battery. took out and disassembles the starter various times. and do you know what it turned out to be. it was the terminal. though the terminal was clean and the post was clean too the terminal lost its ability to conduct electricity and would not send the correct volts to the starter. i replaced both terminals at the battery and whamo! instant gratification....................!!!!!!! and also if i might add. the cables also lose their ability to conduct electricity and cause the exact same problem. both of these items can be the problem.

 

Thanks for all the replies guys. Its a 2000 scrambler 500. I tried changing the plug too. Same thing no matter which plug I use. The plug has good blue spark on it when pulling it but it does look alot weaker and more intermittent when I use the starter. I've pretty much eliminated the cable issue also. I've bypassed wires with more wire to check each one. Same thing every time. It's just about has to be something breaking down. The coil maybe, but I'm not sure because it starts so easy on a pull and runs to good when running. I think I'm going to replace the stator if I can find a used one cheap. I was reading somewhere where someone had almost the same problem as me and it turned out to be the stator. An expensive guess but I'm at a loss. I've got to get this fixed though because I don't like being out on a trail and the pull rope my only means to start it. I've had the rope come loose to many times and if that happens on the trail it would ruin the trip for me and the other riders.

 

You could test the stator and the ignition coils with an ohm meter. The stator charges the battery so I think it is OK. I do not have the specs on a 2000 but on a 2002 they should be:
Ign charge coil 19 ohms, no ground connection
Ign trigger coil 97 ohms, no ground connection
Battery coil .22 ohms, no ground connection
Yours should be close to this or someone else may have better numbers.

You could also try disconnecting the kill wire from the CDI ignition box. The ignition system on your bike is like an old lawn mower and does not need 12 volts to work. The kill wire on an 02 is Black and is shorted to ground to stop the engine.

If I remember right the start switch on a 2000 is part of the kill switch on the left handle bar. If disconnecting the kill wire from the CDI ignition box helps check the start/kill switch.

 

Just a shot in the dark, but hows the compression? I've saw 6 volt tractors that were really hard to start, and then converted to 12 volt with the 6 volt starter and it spins much faster allowing a faster start. Just a thought

 

I've checked the compression (good) and the stator and it checks out with the ohm meter. The only funny reading I'm getting is when I check the output of the stator to the voltage regulator. It says the 2 yellow wires should show atleast 7 amps from the stator. My meter shows nothing there but it could be messed up on the amp setting. The red wire from the voltage regulator when disconnected at the regulator shows 10 volts on the regulator side and 12 on the harness side with the bike running at idle. So the stator is putting something into the voltage regulator. I'm just not sure what the voltage should be on the red wire. 6 volts doesn't really seem right but I am showing charging at the battery. Thats why I think the problem is in the voltage regulator or the stator. I'm just not sure which it would be. Maybe I'll find another meter and retest those yellow wires.