1984 Yamaha 150ETXN, No Spark

[edgutgesell]

I posted several weeks ago regarding a problem I have with my Yammie 150. I will restate the problem. When I pulled the boat and winterized it last Nov. the engine was running fine. Upon getting the boat ready for this season, I attempted to start the engine at a local launching ramp, and it would not start. It would not even kick at all. I attempted to troubleshoot while on the muffs at my house, and apparently there was no spark. I consulted my Yamaha factory manual, and ohmed out the pulser, charge, and lighting coils. All ohmed out correctly with the exception of one of the charge coils. The Yamaha manual specified a resistance of 127 Ohms, +or- 20%. My digital VOM read 24 ohms. I think that my digital VOM is reading correctly because it read the Pulser coils, low speed charge coil, and Lighting coils within factory resistance spec's. I did a search on charge coils and Yamaha 150 to see if there may have been another topic in the past that confirms the charge coil resistance. I found a topic titled "86 Yamaha 150 VPro" dated Nov 25, 2004 posted by "quat" that indicated that the low & high speed charge coils resistance between BRN/RD=1.49K Ohms which agreed with the reading I got on my engine and that the reading between BLK/RD & Blue = 24.2 Ohms. Since then I bought a Sealoc manual for 1984 to 1990 V4 and V6 engines and they spec'ed the resistance the same as the Yamaha factory manual!! (127 +- 20%) I checked the part #'s of the stators for 1984, 1985 (6G5-85510-10-00) and 1986 stator (6G5-85510-11-00). Is it possible that I have a stator in my engine that is the incorrect part? What is the correct resistance, 24 Ohms or 127 Ohms??? <br /><br />Also, since then I checked the spark with a homebrew spark checker that can check spark from 1/4" to 1/2" on all six plug wires simultaneously and got no spark on any wires at a 1/4" gap. I tested the spark tester on an Evinrude 70, and it worked fine on all three cylinders simultaneously! I disconnected the white wire from the ignition controller to the CDI to eliminate "kill" switches and I got no spark. I tried using an oscilloscope to scope the primaries to the coils, but it was difficult to determine what was right or wrong. I was seeing some pulses, but they seemed very low level. (Could have been noise) The factory manuals do not give voltage level spec's for primaries, charge coils, pulser coils, etc. In another topic, rodbolt gave some voltages off the top of his head that I think were as follows:<br /><br />Primary coil voltage - 58V to 80V<br />Charge coil voltage Brown-Red - 145V<br />Charge coil voltage Black/Red - Blue - 40V<br /><br />I just ordered a "DVA Peak Reading Voltmeter Adapter" so that I can read the voltages with another piece of test equipment besides the OScope.

 

[Ray Neudecker]

Re: 1984 Yamaha 150ETXN, No Spark

The 84 model had some different electrics from the later models. Be sure your battery is really fresh. If it doesn't spin fast enough you get no fire. Some times hooking a charger to it while attempting to start will get you fire. If so replace the battery. Do not use a deep cycle battery for a starting battery

 

[rodbolt]

Re: 1984 Yamaha 150ETXN, No Spark

the voltages were from an early ninties. they will be fairly close<br /> the coil primaries wont work much below 50Vpeak. the pulsers usually work between 1 and 4 v peak. the electrics are some different but not that much. thats the nice thing about trons. they can only work one way and it does not matter who what or where it was built. except maybe the english Lucas stuff.

 

[edgutgesell]

Re: 1984 Yamaha 150ETXN, No Spark

Ray & Rodbolt,<br /><br />The batteries, starting and deep cycle, are brand new and were fully charged. I will hook up the charger the next time I troubleshoot the problem. (hopefully this weekend!) Rodbolt, thanks for confirming the voltages and adding the pulser voltages. I think that confirming that the voltages are within spec. will tell me more than the resistance reading. The reason I listed the part numbers for the stator was that there is a part number difference between 84/85 and 86. (could there be a resistance difference?) I would think that if there was an electronic (resistance, 127 ohms vs. 24 ohms) difference in the charge coils between 84/85 and 86 that the CDI would also be a different PN. The PN for the 84/85 CDI (6G5-85540-12-00) is the same as the 86 CDI. <br /><br />One thing I didn't mention in this topic is that when I got the boat ready in March, I noticed right off the bat that when turning on the key, that the oil pump in the subtank was pumping continually and overfilling the main tank. I had had this problem intermittantly in the past. I troubleshot the problem via the Bass & Walleye article and it turned out that the oil controller was driving the pump continuously. The switch in the main tank (#1) was working properly. I replaced the oil controller with a new one before I attempted to start the engine. Could something in the oil controller circuitry effect ignition? There is a wire that runs from sw3 in the main tank sensor that runs to the thermo sensors and ends up at the rectifier regulator and ultimately to the ignition controller. (pink wire) I couldn't see how that could effect shutting down the ignition completely but then I don't know how the ignition controller works. I did not disconnect the pink wire from the ignition controller only the white wire to the CDI. Is that (pink) circuit the one that limits the RPM to about 2000rpm when main tank oil level gets very low? Will it (pink wire) going to ground shut down the ignition like the kill switch does?<br /><br />I think that I have alot to learn about Yamaha outboards and that is why I am picking your brains. I really appreciate your inputs and I don't intend becoming a Yammy tech. I do realize my limitations and want to know when I am past what I can reasonably do on my own. When that happens I will see my local Yamaha tech.

 

[Ray Neudecker]

Re: 1984 Yamaha 150ETXN, No Spark

The difference in the stators is because the flywheel trigger is 90 degrees out of phase when compared to the 86 and later models. The white wire from the control unit is the output pulse from the control unit to the ignition. The pink wire is the input signal to the unit.