Yamaha starting problem

[sbaker7398]

The setup is twin 1990 yamaha 200's with two batteries and two battery switches. I forgot to turn off the battery swtiches and the VHF so naturally both batteries went dead. I replaced one battery with a fully charged battery, started both engines and everything went fine for the day. Today I go down to the dock, new battery is fine, old battery is pretty weak but to be expected as I had only run the boat for a few minutes since it was drained. Engine 1 starts right up, engine 2 nothing. So I take the cover off, tinker for a while and eliminate obivious things like fuses etc. Here are the symptons<br /><br /><br />1) on new battery engine 1 starts and runs fine. On engine 2 the starter will spin, engage flywheel but either very slowly spins flywheel a quarter turn or flywheel does not turn at all <br />2) I took out all the spark plugs and with no load and using new battery the starter and flywheel seem to spin pretty fast <br />3) spark plugs back in and we are back to (1) <br />4) I took a pair of jumper cables directly from new battery with engine 1 running to the starter and the results were same as (1) I think this eliminates bad wiring as a possible source of the problem.<br /><br /><br />I found a few more spare minutes and I went down and swapped starter 1(good) from motor 1 to motor 2 and starter 2(presumed bad) to motor 1. It is not a starter problem as the starter 2 (presumed bad) worked fine on motor 1 and starter 1(good) exhibited the same problems on motor 2. Again I used jumpers direct from the battery to the positive and negative terminals on the starter 1 on Motor 2 and had no success. I have read discussions that mention solenoids but I am unfamilar with them and their role in the starting process.<br /><br /><br />Could a bad solenoid create this problem even though I have the jumping wires direct to the starter? Could the one good and one bad battery be the problem although I am only using the one new battery through the switch. Any other ideas, thanks

 

[rodbolt]

Re: Yamaha starting problem

try switching batteries. sometimes a bad battery especially an old one that got drained will faail and act as a second load on the system and kill the good battery. why did you not just buy two batteries? to test the solinoid attach the black DVM lead to one batt term and the red DVM to the starter side soliniod term and have an assistant acuate the starter or take the brown soilinoid lead to the batt+ term. if it drops reads more than about.5 volts its failing if its less than 5 keep hunting. that method can also be used to check batt cables as well. all voltage is is a potential differene. if you have over .7v potential difference between the batt + term and the batt +terminal on the starter find and repair the bad connection in the cables. do the same with the ground lead. any more than about .7v potential across the batt- terminal to the engine block while starting will indicate a bad cable or connection.all that solinoud is is a low current controled high current controling device. the starting system is capeable of drawing 200 amps or so/. the keyswitch and wireing cannot handle that. so the place a magnetic contactor near the starter motor. when energized it brings a copper alloy disc in to make contact between the starter terminal and the batt positive terminal. its rare to see a failure. the other problem that can happen on the 25" version of that motor is the steady bushing in the midsection just above the water pump can corrode and grab the shaft. but in your case I suspect a defective battery or a bad cable connection. its not a good idea to have the good engine running and attempt to start a dead engine with an outboard. sometimes the alt current draw will burn out rectifiers and stators. kinda like crab pot pullers do when the puller battery is failing.