Ducati.ms - The Ultimate Ducati Forum banner
  • Hey Everyone! Enter your bike HERE to be a part of this months Bike of the Month Challenge!

1 - 11 of 11 Posts

·
Registered
Joined
·
16 Posts
Discussion Starter · #1 ·
I have a 500 Pantah that does not start reliably. I have read the starter draws too much power from the coils and the spark plugs do not fire under compression. I check the plugs out of the cylinders and they spark. Not a real strong spark but they spark. I tried starting fluid and no luck. I also read that as soon as the starter button is lifted the coils will fire enough to start the motor. I have actually seen this. Does anyone know anything about this problem and is there a solution? I seem to remember something about a relay in the starter circuit? Help please
 

·
Registered
Joined
·
425 Posts
If what you say is the case then if you jump start it from another battery there should be plenty of poke to fire your coils and give it a fat spark. worth trying just to see if it is a voltage drop caused by the starter first.
 

·
Registered
Joined
·
152 Posts
New battery leads may help. You can test this by using a set of jumper leads. place the negative on the negative battery terminal and the other end on a good clean part of the motor. Then the positive on the positive of the battery, switch the key on(all this with the original battery still hooked up to power the ignition etc) then touch the positive end of the jumper cable straight on to the bolt on the starter motor where the old main power lead goes to. If it makes a difference the you will benefit from new leads.
 

·
Registered
Joined
·
3 Posts
I have a 500 Pantah that does not start reliably. I have read the starter draws too much power from the coils and the spark plugs do not fire under compression. I check the plugs out of the cylinders and they spark. Not a real strong spark but they spark. I tried starting fluid and no luck. I also read that as soon as the starter button is lifted the coils will fire enough to start the motor. I have actually seen this. Does anyone know anything about this problem and is there a solution? I seem to remember something about a relay in the starter circuit? Help please
You have to modify the wiring. Alla power is routed through the ignition lock and the kill-switch. This means about 2 meters of extra wiring and the voltage drops over the coils.

The relay shall connect the + on the battery directly to the + on the coils. The relay shall be controlled by the original wire to the coils. By the the ignition lock and the kill-switch will operate the relay and everything will work as normal ... except from that the Pantah will start as soon as you just touch the button!

A typical indication of your problem is that the engine fires when you release the the starterbutton - no matter how long you have pushed it.
 

·
Registered
Joined
·
16 Posts
Discussion Starter · #6 ·
What has been said by all is the case. When you hit the starter the battery voltage drops from about 12.6 to 11.1 at the battery. I pulled the starter, which is not easy on the Pantah compared to a new bike, and then cleaned the starter. Brushes were sticking and it was full of carbon. After cleaning it it does not draw as much power. Still drops below 12 volts. Now there is already a relay in this system. One wire comes from the ignition switch to the relay and the two other wires go to the starter and come from the battery. So you say to route a new wire from the battery to the coils and go through the relay. Control the relay with the wire going to the coils that currently is through the switch and kill button circuit and not going through the starter circuit.
 

·
Registered
Joined
·
55 Posts
This is very interesting to me. My F1 has these exact symptoms. It's.a.nightmare to get started when cold. As soon as it fires its good for the day. But the cold start issue keeps me from riding it. Just as others have descibed, it fires briefly when the starter button is released. Very frustrating.
 

·
Registered
Joined
·
425 Posts
I think what he is saying is run a wire from the starter side of the relay to the coils. Leave all your other wires in place. This means when you have power to the starter when pushing the start button you also have a second feed to the coils which will cut out again once the starter stops and your original wiring works as it did. If thats not what me means its what i would try as its easy to do as an experiment.
Of course when you measure your voltage drop measure it at the coils not the battery. It will drop to 11+ volts at the battery anyway. What the guy is saying is because of the miles of wire the volt drop at the coils is even more so a piggy back wire will give you the 11+ volts at the coil which should be plenty
 

·
Registered
Joined
·
115 Posts
Based on a modification I did to my Alazzurra which had the same problem I can suggest this change to the wiring harness. It allows current to flow directly from a new fuse which is powered directly from the battery but which is controlled by the original ignition circuit.

Use a new standard four terminal relay with the single orange wire from the kill switch connected to terminal 85. This will activate the relay. To terminal 30 of the relay connect a wire from the new fuse. Terminal 86 connects to ground. From terminal 87 run a new wire to the connector (replacing the single orange wire) that joins the single orange wire from the kill switch to two brown wires that go to the transducers.

This is the modification that Hekto is referring to. I am basing the wire colours on a circuit diagram I found on Ducatimeccanica. The modification should be fully reversible should you wish to go back to the original configuration.

As Hekto says, the bike should now start easily.

Bruce
 

·
Registered
Joined
·
4 Posts
I have a 500 Pantah that does not start reliably. I have read the starter draws too much power from the coils and the spark plugs do not fire under compression. I check the plugs out of the cylinders and they spark. Not a real strong spark but they spark. I tried starting fluid and no luck. I also read that as soon as the starter button is lifted the coils will fire enough to start the motor. I have actually seen this. Does anyone know anything about this problem and is there a solution? I seem to remember something about a relay in the starter circuit? Help please
The insulation on the wires to the Bosch ignition sensors have a habit of rotting away and shorting - could be that see the threads on UK Ducati forum
 

·
Registered
Joined
·
1,605 Posts
I had this exact problem on my 94 M900 with high comp -944 kit. I replaced the starter circuit with a Motolectric Starter Kit that was made specifically for the Monster. In fact, I installed the kit when Michael, the owner of Motolectric present. Before the new kit installation, we documented the voltage at the + terminal of the battery when the starter was button was pushed. It dropped down to around 9 volts which was not enough voltage to fire the plugs. The motor would turn over but no start. Sometimes when you let off the starter switch the bike would back fire.
After we installed the new starting circuit (bigger guage wire, simplified the connections) The voltage dropped only about a volt and the bike started immediately.
There is no kit available for your bike, but if you replace the high current wiring with larger gauge, new wire, the problem should be fixed.
 
1 - 11 of 11 Posts
Top