no spark? 1984 v4 115 Yamaha... what don't I have hooked up that needs to be?

[heatz1express]

o.k. so I purchased this 1984 Yamaha V-4 115 precision blend outboard-heard it running. Brought it home and have now got it installed on the center console that I am outfitting. I converted from the 703 side-mount control to the 704 binnacle control with trim/tilt. Had to pull ignition, kill switch and choke switch from side-mount and install in dash of center-console but I did not have to disconnect them from harness. Disconnected neutral switch and trim/tilt switch wires from side-mount and connected them to binnacle wiring. All tested now and work.
Oil reservoir on motor has oil in it and external oil tank has oil in it and wiring connected to motor. I've got fuel.

Turns over but she won't fire-no spark!!!
When I bought it and they test ran it for me there was some confusion over what had to be hooked up to get spark and then they realized there was no oil in the reservoir, Once oil level was brought up in the reservoir she fired up instantly and ran nice.
I thought I was good-to-go but apparently not. Do I have to have the gauges hooked up? Any Yammy guys with the answers out there? My feeling is that I have not got something hooked up, the motor is sensing it and thus no spark. Insights anyone?

 

[99yam40]

Re: no spark? 1984 v4 115 Yamaha... what don't I have hooked up that needs to be?

key switch and kill switch are the only things that will kill spark by grounding ignition.

low oil will not keep motor from sparking

 

[heatz1express]

Re: no spark? 1984 v4 115 Yamaha... what don't I have hooked up that needs to be?

key switch and kill switch are the only things that will kill spark by grounding ignition.

low oil will not keep motor from sparking

if that is the case, since turning the key causes the motor to turn over, doesn't that mean it has to be a problem with the kill switch?
seems too simple.
This outboard is a precison blend 2-stroke and I am sure I have read in other threads about problems with these motors not starting because of no oil in reservoir! - something about system protecting engine from being run with no oil in the mix!

 

[99yam40]

Re: no spark? 1984 v4 115 Yamaha... what don't I have hooked up that needs to be?

That old of a motor I am not familiar with, but most all others, low oil will sound alarm and reduce/ limit RPM to about 2K not kill spark.

The kill wire runs to key and kill switch, anything that grounds that wire wire kill spark, even a short to ground in harness

 

[heatz1express]

Re: no spark? 1984 v4 115 Yamaha... what don't I have hooked up that needs to be?

That old of a motor I am not familiar with, but most all others, low oil will sound alarm and reduce/ limit RPM to about 2K not kill spark.

The kill wire runs to key and kill switch, anything that grounds that wire wire kill spark, even a short to ground in harness

Thank You for your input.
Part of the problem I am having is that the wiring diagrams from manual and on-line are impossible to read! cant tell if a B is a B or an R or ? kind of helps to know if a wire is red or black!

 

[heatz1express]

Re: no spark? 1984 v4 115 Yamaha... what don't I have hooked up that needs to be?

Update. Got spark by completely disconnecting oil reservoir float switch/sensor. Since I am running 50:1 fuel mix and bypassing VRO altogether, I took her out for a boot( 10 min. ride no wake zone then 10-15 min. ride on lake up- to full throttle briefly then 10 min. ride again no wake zone back to dock. while docking motor stalled and now won't run again!

 

[jeff acton]

Re: no spark? 1984 v4 115 Yamaha... what don't I have hooked up that needs to be?

Having similar problems with my 115 Yamaha. One day it runs fine and next day no spark. We have tried everything. I never thought about the oil sensor, so maybe I will try that. Jeff

 

[heatz1express]

Re: no spark? 1984 v4 115 Yamaha... what don't I have hooked up that needs to be?

hey Jeff. the one I have is running great now. have precision blend disconnected completely and am running 50 to 1. Definitely going to work towards getting it hooked up again though as mixing the gas is a pain in the ***! plus the mix is a little rich at low rpms. good luck with yours.