View Full Version : Promblems with Tohatsu
jerson
30-12-2006, 02:59 PM
I have a 7 year old 30hp Tohatsu, it has been running fine with several trips last week. I dropped it in the water yesterday to fine the battery was flat, I was able to get it going with the pull start & ran it for about 40 minutes with no charge in the battery after running. I replaced the battery today, reconnected it, when I tried to start it the motor was very slugish, I noticed smoke coming from the insulation on a wire that is bolted to the housing that the motor pivots on when steering with the other end bolted to the motor leg. I then isolated the electrics to the rest of the boat & tried again with the result the hole motor has shut down.
The reason for isolating the motor is I installed a new sounder but used the existing power wiring as both sounders are the same make.
Has anyone got any ideas what this could be.
gone_fishing
30-12-2006, 07:12 PM
gday jerson
sounds like youve got a bad earth
im guessing with what you have described the lead that started smoking is the earth lead
if this is the case you may have to replace it now that its smoking
but first check with multimeter if you can get one the battery voltage to make sure its not a flat battery
then go around all you connections pos and neg undo them clean them and refit them do this with the battery disconnectted id start with the connections of the lead that was smoking may be lose
try these simple checks if prob still there talk to auto elec.
good luck
jerson
30-12-2006, 11:22 PM
Gone Fishing
Thanks for the reply.
The lead I spoke about does look like an earth lead, it has a loose insulation covering it that only covers part of the wire. This wire looks to have touched the leg of the motor when it arced leaving a mark on the leg & melting part of the insulation.
One strange thing is the 15amp fuse encased in the motor is still intact.
I think I can see a trip to the doctor coming up.
Deiter
31-12-2006, 06:18 AM
G'day Jerson.
Mate, few possibilities here. A 'bad' earth or connection on the nuetral at the starter motor could be causing the current to find an alternate path,i.e. through the block earth. However, the fact that it is flattening the battery suggests a short circuit somewhere. I am not really up with the electricals on your sort of motor, but that wire joining the transom bracket and the leg of the motor would be a bonding earth, which makes sure that the leg and bracket are at the same potential (voltage). If it is smoking, you have short on one side or the other, more than likely the leg/motor side.
Does it only smoke with the ignition switched on? Only when trying to start?
Knowing this info will let us know where to look next, but for know, have a gander under the cowl and do a visual inspection of the wiring. I'd be paying close attention anything associated with the starter motor.
Damo
jerson
31-12-2006, 12:03 PM
Damo,
Thanks for the interest.
When I first noticed the smoke coming from the wire I disconnected the power feeding the accessories & tried again with just the motor connected. It tried to start without success & then no charge went to the motor, not even the auto choke. the battery is new with full charge. I've checked under the cowel with no success.
Roughasguts
31-12-2006, 12:15 PM
You checked the main fuse under the cowl probably blown.
jerson
31-12-2006, 12:18 PM
Damo,
To answer your question, yes it only smokes when starting, the motor starts with ignition on & using the pull start. This was how I started the motor last trip out but didn't notice any smoke.
The problem was seen when I replaced the battery, when I started the motor it was trimmed all the way up, this is how I noticed the smoke.
The wire in question has a loose insulation that can move & is only about 2/3 the length of the wire.
I will put a meter on the battery to see if it is still fully charged.
Happy New Year.
Deiter
31-12-2006, 02:04 PM
Jerson, loose insulation, no insulation, doesn't matter, its only a bonding wire. However, it was probably the insulation smoking that alerted you in the first place. That means that that wire is conducting a lot of current for its diameter. Same thing with a bad connection - too small of a surface area to conduct the current = heat.
Normally, i would think that wire would just be there to prevent electrolysis. Not load carrying.
If it is getting hot, you have a short. Is it an ally boat?? If so, something may be shorting to the block, then through this wire, to the bracket and then to the transom. Shouldn't happen unless your Neg terminal is grounded on the boat somewhere.
Also, did you disconnect the battery leads and put them the wrong way around?? It does happen. Never to me though :-X ahem... yes, now ah, where were we?
Check those things and get back to us. Maybe by then a proffessional will have this sussed ;)
Damo
jerson
31-12-2006, 04:22 PM
Well fella's it's time for me to put the pride in the pocket.
I cleaned the connections to the battery terminals (no corroded, just discoloured) now it nearly jumps of the back of the boat.
This could have been fixed while fishing. IDIOT.
THANKS VERY MUCH TO ALL CONCERNED.
Jerson.
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