Yamaha Help needed.

[Dave Q]

I am working to find a gremlin in my F75 tiller. Working on eliminating things it could be....Question- is it ok to "see" if the motor will start in gear. Not run it.. just see if it will turn over. I am fighting a situation where more and more often the motor will not even turn over-nothing- just the sound of the "hum/click" of the starting sequence- but nothing when the key is turned. The fix every time, a good# of times(so far) has been to move the (tiller) shifter in and out of gear(quick back and forth) The neutral safety switch located on the port side,part of the shift linkage, has had the switch cut off and the wires joined so it cant be that. Would a problem like this show up in a code scan? Thanks for any help.

[bvs]

Yes, its ok to try and start the motor in gear, just make sure you have water flowing through the muffs and don't run the motor too fast or too long.

I've seen this problem before and it sounds to me like a weak battery or starter. Put a voltmeter on the battery and if it doesn't drop below about 10.5V when you turn the key then you probably need a new starter. Shifting the motor in and out of gear is "knocking" the crankshaft a bit and loosening things up just enough that the starter can turn over. Take a hammer and tap on the starter while turning the key and I'll bet you find this works as well.

[Dave Q]

Well this is what I have learned.There IS a second net. saf.switch, it is located in the bottom cowling on the starboard side near the front. It is easy to see if the fuse cover is removed. A button is depressed by an inch long s.steel strip that is in turn depressed by a shifter linkage arm. This switch is added with the tiller arm kit. I learned this from a Yam. rep. as well as seeing a parts schematic that was emailed to me. I ran the motor(on muffs) and shifted, started it maybe 30 times and it would not fail to start.....now that I want it to so I can bypass the switch and see if that is the problem.....The night before it "did it" and failed to start a # of times....grrrrr. The battery is on its 4th yr, it seems good- 13.4v and spins the motor over v.fast. It cant be the kill switch as it will still crank just not start if the kill switch is activated.........on it goes...........

[MarkG]

No it would never be the kill switch as that just kills the spark,not the starter.

You should not need to actually START the motor while trying to diag the starter problem. All you are looking for every time is to see the starter motor spin. Forget the muffs,,pull the kill switch. Then you can spin that starter all you want.

In regards to trying to see if will start in gear,don't bother. You do not want the motor to start in gear anyway,,it proves nothing. In gear should ALWAYS open the circuit regardless of the condition or position of the switch,unless you of course have it bypassed. If you have it bypassed,no need to bother because the starter circuit would not even be able to tell what position the gear shift is in. So again, proves nothing.

On my F40 tiller,I too had a starter problem.I found the Nuetral switch
in the bottom pan had just loosened up from it's mounting bracket,which caused the switch to always be open regardless of the physical position
of the shifter. As far as I could tell,I only had 1 switch.

If you have the switch bypassed, (it's unclear if you ever bypassed that 2nd switch yet ) and it still intermittently fails, you have ruled out those switches. Then You need to look at the keyswitch,the solenoid,or the starter motor itself. A voltmeter or some bulb type circuit tester can help track down where you are loosing the circuit. But when it's intermittent,can really be a bear. I was lucky my failure was solid.

Backtracking ,before you bypassed anything,The best evidence you have come up with so far before you discovered that second switch,,is that when it actually failed for you,popping it in and out of gear got it working. If sure it's not just loose in its mounting bracket, the conclusion I would draw is that switch is starting to fail,and should be replaced.

[Dave Q]

Thanks Mark G. I am waiting/wanting it to fail ie: not turn over(in the drive way) so that I can bypass the(second) n.s.s. in the lower cowling and see if that is the problem. The switch is set up with male/female plugin connections so I can unplug the switch and reconnect the wires, bypassing it, to test if it is the switch. I hope it is, that would be simple to fix. The big problem is its intermittent, as you said, a bear. As for the muffs I was just being over cautious, I did have the kill switch pulled so it would only crank over not start. I will post again with an update. Thanks again.

[MarkG]

Next time you get it to fail in your driveway,rather than bypass the neutral switch,hang a voltmeter on it and see if losing voltage to one side of the switch when the starter fails to spin. Much more reliable way than bypassing. Set it up as Negative meter lead to ground or some other negative terminal,positive lead to the switch.

In neutral,with the key turned to start, should see 12 volts to BOTH sides of switch. If only one side,replace switch.

If no voltage to EITHER side of switch,may be the keystart switch.(very unlikely you will see that)

If see voltage to BOTH sides, but starter still fails,check voltage at Starter motor.
If there is voltage at starter,but no spin, bad starter motor.

If no voltage on the starter, could be the solenoid. Depending on how they grounded it, there may be 2 terminals on the solenoid.,may be 4 (neg and pos). 2 to "pick" the solenoid, 2 to pass voltage to the starter motor when solenoid is picked. If see voltage at the terminals that operate the solenoid,but no voltage on the one(s) the starter motor is connected to,...bad solenoid.

There may be one or more plug and terminal type connectors in the wiring harness,make sure they are all seated and tight.

Good luck

[Dave Q]

MarkG wow thats good info.....and explained in a way so even I can understand lol. Thanks I will post back but right now the motor is on a roll, it hasn't failed to start, I cranked it maybe 10-15 times last night.?!

[MarkG]

Of course it won't fail !
Will always wait till you're out on the water.
That's just the way it is with gremlins.

[Check this]

One more quick question for you - when your motor fails to start, does your tilt and trim still work? If it does, then my tip probably isn't going to help you, if it doesn't, then check your ground (negative) main battery cable where it attaches to your motor. If you follow the cable from the battery, you will find the connection. I had intermittent starting problems with a Yamaha 150 4 stroke (very frsutrating), and this turned out to be my problem. Due to the nature of the way the connection was creating slag from arcing on itself from being slightly loose, it would lose conductivity on an intermittent basis. Jostling things around randomly (taking the cowling off and fiddling with wires) seemed to help my problem before I had finally determined the real culprit. I had checked the connections at the battery terminals but hadn't thought to check the connection at the motor itself.

[Dave Q]

on it goes ....still hasn't failed(last weekend on the water it failed a good# of times. grrr) I will add when it fails everything works, just no crank. I've fiddled with /tapped plugged/unplugged etc. the switch....maybe the gremlin is gone, I'm not too hopefully... but again tonight a good # of cranks(kill sw. pulled) and all is well???

[ndfishin]

Dave Q have you found out why your 75 yamaha will not start at times? I have a 2006 yamaha 4stroke and it is doing the same thing the only problem is it doesnt last very long and only does it when cold so still troubleshooting it to see where problem is. Under fuse cover in engine compartment there is a relay just under the fuses if you take it out of gear and use a screwdriver you can jump these two terminals and it should crank over this is the starter relay so if it does crank then it rules out the starter and the battery. Hope this helps.