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Discussion Starter #1
WHen I put my bike away last fall it was running fine. I had the carbs adjusted and also the valves. The mechanic found that the prev. owner had not disconnected the air pump when the Corba pipes were added and that was cause of the backfires. No more backfires now. This spring I bought a new battery and when I tried to start it the battery would barely turn over the starter. CHanged battery again and also took the starter out of bike and had it checked. Starter was OK, but still turns very slow!!. We went for a ride and stopped for a break after 1 hour and when I tried to start the bike, the battery was dead! Not enuf juice to start the bike. Had to push-start the bike. I was told to check the battery ground and found it went directly to the starter. It had been altered, because it usually goes to the engine.
Wondering if this is the problem? It was like that since I have the bike, 3 yrs now.
Any ideas what the problem can be??
Thanks
 

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Battery

Melmo,

I don't think moving the negative wire to the starter would be the problem.

Maybe first be sure the battery and charging system is OK. You will need a volt meter. The charged battery should be about 12.7 volts DC, engine not running. Start the motor, check battery voltage again maybe rev it up just a little. Give it a minute then check battery vlotage again. It should be about 14 Volts DC if the battery is fully charged. It could take it a minute to come up. If the voltage does not come up you are not charging.

The starter is the highest current device on the bike so lots of current. It does not take much resistance to be a problem. Fortunitly there is not much in this circuit. Maybe disconnect the negative terminal frome the battery for safty and clean all the connections in either positive or negative wires, terminals, bolts, etc. losen the connection clean it and reconnect it one at a time. There is a starter relay, remove it and look at it, try to see if the contacts are carboned up or burned.

For a test you could try connecting the volt meter leads between the batttery terminal and the starter. Crank the starter if you read a voltage that would be a drop somewhere in the wireing. Do this with both positive and negative if you can. This voltage should be very low you do not want much drop in the wires.

If it passes all these and the starter is OK I would think the problem is mechanical. Maybe the starter clutch. Perhaps by then some one with some mechanical experience will come along.

Dave
 

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Also, if it was a new battery, did you fill it with acid and charge it before install? A Must on new motorcycle batterys!
 

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Discussion Starter #5
Also, if it was a new battery, did you fill it with acid and charge it before install? A Must on new motorcycle batterys!
The battery was bought at a Yamaha dealer, watched them fill it with acid and put on a charger. I went back 5 hrs later to pick it up.
I had them do a load test on battery when I picked it up. It shows 11 volts. The first battery only showed 7, so I took it back.
 

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Discussion Starter #6 (Edited)
battery problem

Melmo,

I don't think moving the negative wire to the starter would be the problem.

Maybe first be sure the battery and charging system is OK. You will need a volt meter. The charged battery should be about 12.7 volts DC, engine not running. Start the motor, check battery voltage again maybe rev it up just a little. Give it a minute then check battery vlotage again. It should be about 14 Volts DC if the battery is fully charged. It could take it a minute to come up. If the voltage does not come up you are not charging.

The starter is the highest current device on the bike so lots of current. It does not take much resistance to be a problem. Fortunitly there is not much in this circuit. Maybe disconnect the negative terminal frome the battery for safty and clean all the connections in either positive or negative wires, terminals, bolts, etc. losen the connection clean it and reconnect it one at a time. There is a starter relay, remove it and look at it, try to see if the contacts are carboned up or burned.

For a test you could try connecting the volt meter leads between the batttery terminal and the starter. Crank the starter if you read a voltage that would be a drop somewhere in the wireing. Do this with both positive and negative if you can. This voltage should be very low you do not want much drop in the wires.

If it passes all these and the starter is OK I would think the problem is mechanical. Maybe the starter clutch. Perhaps by then some one with some mechanical experience will come along.

Dave
The only thing I haven't done yet is to put a load on the battery or starter while both are in the bike. I will be bringing it to a bike mechanic to get that done. I'm thinking now that there may be a charging problem. When I went for a ride and stopped and then tried to start the bike, the battery was almost dead. I had been riding for almost an hour at that point, so I'm thinking that it should have charged up the battery. The slow cranking of the starter was still there.
 

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Discussion Starter #7
The only thing I haven't done yet is to put a load on the battery or starter while both are in the bike. I will be bringing it to a bike mechanic to get that done. I'm thinking now that there may be a charging problem. When I went for a ride and stopped and then tried to start the bike, the battery was almost dead. I had been riding for almost an hour at that point, so I'm thinking that it should have charged up the battery. The slow cranking of the starter was still there.
 
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