Yamaha F150 won't start and trim

[99yam40]

And from what I have read they still have not done a reading with a meter to try and locate the problem.
Just trying to get them to do it

[TownsendsFJR1300]

And from what I have read they still have not done a reading with a meter to try and locate the problem.
Just trying to get them to do it

The closest thing to that was post #20, 9 volts showing on the Yamaha speedometer gauge, but no, no voltage meter tests..

It would certainly make the diagnosis MUCH easier.

[Moskvich]

So, this is today situation. I took my voltmeter and gone on boat with my friend. We are noobs for electric things, but we'll try, here are results:

Both batteries in standby mode: 12.7 V
Voltage on batteries when cranking: 12.6 V
Voltage on starter in standby mode: 12.6 V
Voltage on starter when cranking 12.6 V
Jumper cables voltage while connected to starter: 12.6 V

First we unhooked engine cables from starter and connected one battery directly to starter. We tried to turn engine on, but nothing. Nothing in any battery switch position, even without any sign of life on Yamaha gauges.

I put engine cables back on starter. Positive cable was greased and without any corrosion on it. Negative cable wasn't greased and had 4-5 tiny dots of corrosion, so tiny that I was unable to spot them on first look. I removed them just with my finger and put negative cable back. Then we connected jumper cables from battery directly to the ends of engine cables on starter.
Voltage on jumper cables 12.6 V, voltage displayed on Yamaha gauge 12.6 V, and voila! - cranked, and engine started, trim working!

I thought that now we know where is problem, somewhere between battery and engine. But what if I try now to connect battery on engine as always, via engine cables? I put them back on battery, removed jumper cables, cranked - and engine working again! I turn it off 3-4 times and every time start was without any problem.

First, is it possible that those 4-5 tiny corrosion dots on negative cable end caused that problem? I repeat they were so tiny, barely visible.

Second, my mechanic is total idiot. It is even more sad when you know that he is official Yamaha dealer and servicer for my region. Most sadly for him is that two 20 years old guys (me and my friend) had done something that he has no idea how to do. So I own apologies for all of you who tried to help me here, because he caused all my confusion about this problem.

Third, most sadly for me is possibility that my relay is deformed with rebuilding, due to his idea to "repair" relay. I don't know how long it will be in function in that condition. I say possibility because there is anyway chance that something was wrong with relay. But if something was wrong with it, wouldn't it work yesterday when I put it back on engine together with idiot of my mechanic?

I hope so that this will be end of my problems. Thank you all for the biggest help I received in this case!

[Bilge Rat]

The small amount of corrosion may be an issue BUT it is more a sign of a loose connection that had no di-electric grease on it.
You may have found the problem, people overlook the ground connection as a potential problem.

I would hook up the voltmeter to the motor, turn the key to ON, motor not running. Now while someone is watching the meter start wiggling the cables starting at the battery then to the battery switch and then at the motor.

Grab it wire about 6" from any connector to wiggle. If the meter moves, drops voltage even for a second there may be an issue at that connection.

The relay is another issue in itself. It is good or it needs replacing. Repairing it is not a good fix. Some large relays on machinery are made to be rebuilt, on boats i have not seen a rebuildable one.

Turn the battery switch on and off and try motor, if it ever makes a low power sound replace the battery switch.

If the problem is fixed now good. If it comes back it will be in the wires, connections, battery switch, or battery. The only other cause may be the key switch/ safety lanyard but not likely.

[TownsendsFJR1300]

Glad to hears its running again. Congrates!!!!!!!

Jumping it, by-passed the engine harness AND that battery switch. Re the corrosion, as you describe it, it probably wasn't the problem but it must be clean and tight. Slightly loose will cause issues... Di-lectric grease will STOP any further corrosion.

IMO, besides checking the current factory battery cables (as noted above), get to that battery switch, a loose terminal, corroded or just crappy contacts (worn out) are more likely the issue. Its cheap enough and a lot cheaper than a tow..

That switch is a lot cheaper than that relay your going to have to replace..


BTW, if you didn't have the ground hooked up when initially using the jumper battery, that's why nothing happened, you need a positive and negative power source to work at the same time...

[Moskvich]

Glad to hears its running again. Congrates!!!!!!!

That is the biggest award for me!

Di-lectric grease will STOP any further corrosion.

I'll buy it for sure to grease all contacts, just in case.

IMO, besides checking the current factory battery cables (as noted above), get to that battery switch, a loose terminal, corroded or just crappy contacts (worn out) are more likely the issue.

That's my next step. But if there is problem in cables or switch, wouldn't engine be unable to start again? Is it possible that problem was just in not enough tightened negative cable? I suppose that it suffers a lot of vibrations while engine is working, maybe it softened during long period of use?

BTW, if you didn't have the ground hooked up when initially using the jumper battery, that's why nothing happened, you need a positive and negative power source to work at the same time...

I put negative cable from battery to place where was negative engine cable, but unhooked engine cable. When I hooked engine negative and positive cable back, and then connected jumper cables to them (positive cable end and negative cable end) engine started!

[TownsendsFJR1300]

It should have run if that separate battery was connected to the postive and ground of the engine, don't know why it wouldn't.


In your above post, you are correct.

The issue is in-between the on board battery(or the battery itself) (that goes thru the Perko switch) and the engine. Anything inbetween could be the issue.



In your case:
Battery to cable to battery switch to Yamaha main battery cables (that go direct to the engine). One of those, with a crappy/worn/corroded connection IS causing your problem.

Jumping starting it just BY-passed the above "schematic".

[Moskvich]

In your case:
Battery to cable to battery switch to Yamaha main battery cables (that go direct to the engine). One of those, with a crappy/worn/corroded connection IS causing your problem.

Jumping starting it just BY-passed the above "schematic".

But then happened that I started engine normally, without jumper cables, batteries connected as usual (batteries --> battery switch --> engine cables --> engine), battery switch on BOTH. Nothing changed but negative cable - few tiny dots of corrosion removed and tightened.

I started it 4-5 times, without any problems. I repeat, without jumper cables, everything connected as usual, like before.

[TownsendsFJR1300]

But then happened that I started engine normally, without jumper cables, batteries connected as usual (batteries --> battery switch --> engine cables --> engine), battery switch on BOTH. Nothing changed but negative cable - few tiny dots of corrosion removed and tightened.

I started it 4-5 times, without any problems. I repeat, without jumper cables, everything connected as usual, like before.

Then that corrosion was the issue if its working good now!

I'd still invest in some di-lecrtric grease for those connectors as preventive maintainance...

[Bilge Rat]

The battery switch can be an intermittant problem. It will work fine today and not tomorrow. I have 3 bad ones in a box to give to a buddy for recycling/junk. All started to go bad intermittantly.

Wires and connections can also be intermittant problems. That is why i suggested wiggling everything with a voltmeter hooked up to check for an intermittant issue.

Di-electric grease or battery terminal protector on all large power connections and corrosion-X on all the smaller connections will prevent a lot of connection issues.

Weak connections can be a pain to track down because they don't just work or break and stay broke.
A buddy had a cable problem, if he turned the motor to port it would start. It would not start if it was turned to starboard. It ran fine.
It took getting towed in twice before he listened and had me remake his cable ends.

Good to hear it is working now, keep up on the preventive maintaince to keep the simple corrosion, loose conn. issues from stopping your fun.

[Moskvich]

I'll invest in some di-electric grease for sure, to stop issues like this one in advance. Thank you all for your huge help, now I now where should I ask for help if I have some problem on my Yamaha!