1987 170 with Yamaha 90 2-stroke Neutral Safety Switch questions

[obxdiy]

I have a 1987 170 w/Yamaha 90 2-stroke and she will turn over but not start sometimes, it's intermittent.

I have quite a bit of electrical and electronics experience, just pressed for time, so the 2 big questions I have at this point:

1.  If the neutral safety switch is bad/intermittent for the Yammy 90, should the motor even turn over at all w/the key switch?  Because I can crank the motor all day long...  I've read where if the switch is bad it won't turn over at all - but that was the internet and you know how that goes.

2.  I guess ??  the neutral safety switch is in the throttle control assembly right?  When I did get it to start last week, it was after I putzed w/that a bit - then it magically started without me doing much other than taking the cover off the assembly and giggling the control lever.

3.  Anyone know how to definitively disable that feature for testing?  There is no neutral safety switch on the motor that I can see.  The docs I've had time to read are pointing me to a white wire that ultimately connects to the CDI control pack on the engine...I'm thinking if there's an open or short in the harness somewhere, why not just defeat the whole thing?  I already tried removing that white wire from the CDI terminal block AND shorting it to ground. 

Thoughts?

I know I need to rewire her, but that's a winter project.

Thanks, Eric

[RickK]

You can see if the NSS is working - put the throttle in forward gear. If the NSS is good, you put the throttle in forward and you try to start it, it won't even click. So if it's turning over while it's in gear, the NSS is bad.  If it won't even click, it's not the NSS.

[boatnamesue]

You can see if the NSS is working - put the throttle in forward gear. If the NSS is good, you put the throttle in forward and you try to start it, it won't even click. So if it's turning over while it's in gear, the NSS is bad.  If it won't even click, it's not the NSS.

Rick is correct here ^^^.  With the throttle lever in gear the engine will not crank.  It's highly unlikely this circuit is the cause of your intermittent cranking issue.  Possible, but unlikely as this switch rarely goes bad.  Have you meter tested the ignition system when experiencing the issue?  If not, that's where I'd start.  Since you're experienced with electronics, this should be an easy troubleshooting procedure.  You're looking for the drop in voltz when key is turned ON.  You should see 12v.  Start your meter testing at the ignition key switch, then work your way back to the starter.  And of course first test your cranking battery for full charge, 12.75v, as well as checking all connections from battery to starter.

[obxdiy]

Thanks for the feedback thus far.  Here's a little more info, I'm going to go down and start t'shooting this morning:

-the engine ALWAYS cranks
-the engine will crank with the throttle control in ANY position - i.e. neutral, WOT, fwd, reverse - so that switch is either not hooked up (defeated by previous owner) or bad, for sure - not sure if this will affect the Ability Of Engine To Generate Spark

-I'm cranking but not getting spark. 

I forgot to throw this out there on original post:  maybe it's the kill switch?  I shorted the kill switch and opened the kill switch circuit, seems to be working OK by metering it.  I need to find out where that kill switch connects on the motor itself so that I can take the wiring harness out of the circuit and temporarily defeat the kill switch function at the motor. 

So I'm thinking it's kill switch/associated wiring to kill switch OR an intermittent CDI or a stator going bad I guess.  I've already looked at everything else and specs seem OK.

One other thing:  when I did get it to start one day last week (in the driveway) it was bogging down at higher RPMs kinda like the high-speed jets were clogged, not sure there.  I don't want to go down that path yet til I get the electrical issue fixed, but I'm wondering if that's a sign of the CDI going bad...

Suggestions?

[obxdiy]

OK, findings this morning:

GOT THE ENGINE STARTED - good - HOWEVER, here's some bullet points:
-it's definitely an intermittent wiring problem in the rat's nest behind the switch, I just pulled all connectors apart/re-seated them, previous owner jury-rigged many, many things
-it ACTS like an issue w/the wiring inside the throttle control because it wouldn't start until I gave it WOT
-HOWEVER I think the reason it won't start unless at WOT is because the lower carb fuel bowl is just dumping gas, appears to be a leak in the fuel bowl gasket or something on that lower carb
-OBVIOUSLY the neutral safety switch is not functioning at all and I see a couple of cut wires/splices so I think the previous owner defeated it
-KILL SWITCH kills the motor when i pull the lanyard off, here's what I don't get about the kill switch:  it meters at Open w/lanyard off, it meters at 10MOhms in the run configuration.  Does the kill switch have a resistor inside of it or a diode?  Hmm...

So, my current train of thought is as follows:
-Fix the intermittent wiring problem, that'll solve the intermittent No Spark/non-starting condition
-Fix the lower carb fuel bowl leak and hopefully that'll re-pressurize the fuel delivery and it won't start missing/bogging down when I amp up the throttle.

One other thing I wanna throw out there (good idea vs. bad idea?):  i am running a small outboard tank of gas with a high ratio of fuel injector cleaner in it - to clean out the high-speed jets, etc. at low idle for 15 mins at a time, while parked in driveway.  I'm wondering if that high concentration can make carb gaskets fail because I did not notice the gas leak before...but then again I didn't look for it previously.  Comments welcome on this particular topic.

Sound like a plan?

Thanks

[obxdiy]

OK, status update:
-pulled the oil injector to get to the right side of the carbs, fuel line to bottom carb is very loose, leaking like a sieve
-good thing I decided to get in to all that because i found the oil injector out-feed hose is cracked and almost all the way through - coulda split on the next outing and destroyed my motor

Off to Napa, hopefully getting a full, pressurized fuel supply to all carbs will solve the issue of bogging down/stuttering at higher RPMs. 

Film at 11.

[boatnamesue]

Which yamaha control do you have...the 703 (side mount) or 704 (flush mount)?

[obxdiy]

Neither - I think.  Looks to me to be an aftermarket.  It's flush mount to the binnacle.  It does look original in age though, so not sure if it's a yamaha control or not.   Pic attached.

[wingtime]

That's a Teleflex/morse binnacle

[obxdiy]

Any idea how to identify which model and if there's available drawings and/or parts for it?  I guess I'll pull it out and see if it's something simple or off-the-shelf that I can fix it with. 

[wingtime]

Actually odds are the neutral safety switch is on the motor not the binnacle.

[obxdiy]

The way that a Yamaha 2-stroke mid-80's era works:  you can put the neutral safety switch anywhere you want, but it can't be on the motor unless you have some other type of circuit or mech wizardy happening, because all it does is open the control line to the starter relay.

Mine happens to be inside the throttle control.  The throttle control is one of many devices in the Binnacle Housing.

At the end of the day (in my mind anyway), the biggest problem with boats in general is that the mech and wiring design process has never really been standardized, and any idiot can get a job as an engineer working for a boat builder.  So anything goes and each hull/motor combo is different.  I've had this discussion with one of the chief engineers at the merc test plant a long time a go and some of the stuff he's seen in the industry is similar.

What I've decided to do on this boat is a total tear-out of all instruments and switches from the binnacle housing and rebuild them using my own design.  I'm going to start a Working Group for Arduino Engineers to get an open source project going this winter:  a helm-mounted micro-controller with a companion DAC board (digital-to-analog controller) that will act as the input for all sensors from the engine, and a companion android app that does the job of all instrumentation - i.e. run the boat on a tablet mounted in place of everything.  Of course I'll keep the key switch, kill switch, and neutral safety switch manual, but I'm going to standardize that as well and create a new type of terminal block for all wiring that also will go with the overall strategy.

With the prices of Arduinos, etc. at commodity prices, the goal will be to keep everything at around $300 for the DIY'er.  I'm going to start a new thread in this forum soon to start tracking it, so keep an eye out.  I did an intro on one of the sticky forums when I first signed up, go read that and you'll get a background on what I can bring to bear, technically, on projects of this nature.  It will be fun and very educational!  I'm wondering if I should collaborate with the OpenSkipper team...

[wingtime]

I have that same binnacle on my 170 and I had one on my 200 XF  but it has been a while since I looked at one.

An Ardunio based helm.  Very interesting...