Yamaha Sterndrive shift problem HELP!!!

This is my first post, so please bear with me. I have a 1992 Chaparral 1900 SL Sport with the Yamaha 4.3L I/O. Towards the end of last summer I began having problems with it hanging in gear and hard to shift. After reading several posts on here and talking with people, I have traced it back to an electrical problem with my shift interuptor switch system. I have obtained wiring diagrams and traced through the entire system. In the process, I learned that my key switch is suposed to have a lanyard. Since I bought the boat used, begining of last summer, I have never had one on it and the boat has run fine. Now according to my wiring diagrams, the motor should not run without a lanyard. I have since added one. Since my lanyard and shift interuptor switch are conected in the same system. Why do they not kill my motor. According to what I have learned both switches kill the motor by sending 12V through a black (with yellow tracer) wire to the Ignition module under the distributor cap. And yes I am getting 12V there when the switches are activated, and 0 V when not. Which tells me my switches are working. My first guess was something was wrong with my Ignition module. I replaced the module with no results. Can someone please shine some light on how the motor gets killed when 12V is recieved through my single black wire. Capt Ken are you out there??<br />Thanks,<br />Nick

Re: Yamaha Sterndrive shift problem HELP!!!

I dont have the sterndrive manuals here, can you describe the distributor, what I am asking is to insure which one you have, if its the delco EST it will have 2 places low on the cap to plug in a harness. one a two pin and the other can be a 4 or 5 depending on the module. what pin does the black yellow wire connect to. the are lettered abcde if its EST.

Re: Yamaha Sterndrive shift problem HELP!!!

ok, It is an EST system. My module has a 2 prong plug on one side with letters C and + that go back to my coil. The other side has a 4 prong plug with the letters GBRE. My black wire plugs into the R pin slot on that terminal. It is the only wire on that plug. I then have a green and white wire (that plugs in opposite of my 4 pin plug) that disappears into the windings of the distributor.

Re: Yamaha Sterndrive shift problem HELP!!!

let me look ino it and see if I can tell you tonight later which is the base mode pin and which will kill it if 12 volts are applied. normally its a ground application but merc used it as a 12V application on there shift interupt EST systems for a few years.<br /> and someplace I have that manual.

Re: Yamaha Sterndrive shift problem HELP!!!

Is both plugs connected on the rear of the distributor? Sounds like the small one ain't making contact. And yes, it differs from Mercruiser in that it applies power rather than ground the system. If they are, rock the shift switch to see if the engine misfires. If it don't unplug the two bullet connectors on the switch and hook them together to see if any change. If the engine misfires when you connect the two wires together, then the switch is bad. I've seen folks cut the black/yellow wire under the dash to disable the kill lanyard. I've never had a ignition module give any trouble.

Re: Yamaha Sterndrive shift problem HELP!!!

Yes, both plugs are connected. And I do get power from the switches when they are activated. I am just not getting the engine to misfire when the module recieves its 12V from the black wire.

Re: Yamaha Sterndrive shift problem HELP!!!

capt ken<br /> merc uses 12V to the module to activate the shift interrupt on some of its EST models.<br />it does not use 12V to activate the engine emergency stop, and yes I have replaced many faulty modules that would not kill the system when the shift cut switch was activated, also seen a lot that the electronic advance failed.<br /> so far the EST setup has proven incredibly reliable and works very well.<br />its been used by almost all engine marinizers and rarely gives problems.<br /> its odd they would wire it as an E stop circuit that way, the module does not like 12V for long periods of time due to a lack of heat sink.<br /> but I dont have the yamaha sterndrive manuals at home, they are in wanchese .<br /> we dont see many of the yamaha drives here anymore. most faded away. but they actually worked quite well.<br /> volvo penta used them on many many models as did merc and marine power and a few crusaders. PCM uses a lot now as well. when a PCM base engine is used in a non volvo application you have to wire the EST on the pcm motor for ign interrupt.<br />as the base engine can be had for less than 3500 I get 10 or so a year.<br />some repowers tax the immagination

Re: Yamaha Sterndrive shift problem HELP!!!

If the switches are working and there's power to the module, replace the module.

Re: Yamaha Sterndrive shift problem HELP!!!

Ok, Just put a brand new ignition module in, but the motor still won't stall when 12V is applied. I did get one change though. With the engine off (because it is hard to hear over a running motor)and the key switched to on, I can here a click comming from the ignition module when I manually close the switch. This tells me, the ignition module is now working, but still not killing the motor. The only other thing I can come up with would be the distributor. $175 on a new distributor is alot to be taking a guess on!! The other option I thought about was just forgetting about the ignition module and intalling a normally closed relay in the coil power circuit that would open and kill 12V to the coil when 12V is applied. Any ideas or suggestions. It is getting pretty warm pretty fast and the boat is no good sitting in my garage.