Just bought an older Honda 100. Put in new plugs and fresh fuel. Starts up first pull, idles great but dies when put into gear, any thoughts?
Just bought an older Honda 100. Put in new plugs and fresh fuel. Starts up first pull, idles great but dies when put into gear, any thoughts?
Been tinkering with motor more tonight. I can put the motor in gear without stalling as long as dont let the shift handle fully ingauge but the lower unit is fully ingaged. Works the same in both forward and rev. There seems to be a switch that the shift handle activates when put into gear that is killing the motor. Any help would be appreciated.
Look inside the case just inboard of the shift lever. There should be a switch there with a blue wire and a black with white stripe wire. That is the neutral safety switch. Mounted to the shift selector shaft is a sort of "V" shaped piece of metal that travels through the center of that switch when the shifter is moved. That metal piece interferes with a magnetic field inside the switch when forward or reverse is selected.
I must confess that I don't know why that switch can keep the engine from starting but isn't supposed to kill it after it is running. Which is exactly what your problem sounds like.
I suspect that the switch is in parallel with the "operating" ignition but I don't readily see that in the info I have. I also suspect that your problem is in the "operating" or "running" ignition system and not in the switch. The only reason it starts and idles is because the switch is operating properly. That is all speculation of course.
I will be studying the ignition system to try and figure that out for you (and me) but, in the meantime, maybe someone else here already knows the answer.
Hook up a timing light and see if you loose spark when you move the shift lever fully forward !
Thanks for your reply. It seens that the problem comes and goes. I took off the safety switch to check for any visual damage and reinstalled. Initally had the same problem, then it ran great with the shifter fully ingauged. I switched from forward to rev several time for about 15 min leaving it idle in gear for 10 min or so then shut the motor down, put into neutral and restared, put into gear with shift handle fully ingauged and motor dies. Can I bypass the neutral safety switch to see if it may be the cause before buying a new one?
Slow down,-----the nuetral safety switch prevents cranking with electric start when in gear.-------------Likely not your problem.-------Revisit cleanliness of carburetor as that is the most probable cause of stalling.----There is likely a tiny orifice / passageway plugged with dirt.
Thanks for your reply, keep in mind that I can put into gear without it dying and seems to run great as long as i dont let the shift lever travel the extra inch or so where it wants to stop, then causes the motor to die. Thats why I was thing neutral safety switch. I have cleaned the carb, filter and installed new plugs.
Thanks again for your input.
FYI, I tried to disconect the wires from the neutral safety switch and the motor would not start. I them removed the Neutral safety switch from the bracket so that its not surrounding the shift lever shaft, left the wire connected and the motor runs and goes into gear without dieing. Safety issue now is it will start in gear. Dose anyone know how to test the switch to see if its bad?
Sorry to butt in...
When the shifter is in neutral, the switch is closed. Should read 0 ohms.
When the shifter is in forward or reverse, the switch is open. Should read infinity ohms.
You can adjust the shield plate on the shift arm.
Basically, this is a magnetic switch.
Mike, thanks for the reply, I will reattach the switch and check with a meter. Is the metal tab with the "V" notch the shield plate?
Yes, that is the shield plate.
Mike, glad you're watching. Can you explain the strategy that has the safety switch killing ignition while trying to start but doesn't kill the ignition when you put the motor in gear while it's running?
It is done with mirrors.
In other words, I do not have a clue. All I know is that it works. Only had an issue with these a couple of times, so did not spend much time investigating. The detailed circuit breakdown in the Service Manual does not show it in the circuit. It only appears in the block diagram. It is evidently, a circuit that needs to be closed for starting only.
Any chance someone could tell me the year and confirm the HP of this motor. I believe it a 10hp. B-100L 1600973
1984 The model number is BF100E if you are looking for parts.
Ok, here's how I interpret the neutral start circuit and ignition current "hand off" that occurs on the CDI system that keeps the engine running when the motor is put into gear. My reference is the HELM INC., Honda Marine, BF 75-BF100-BF8 A shop service manual.
The exciter coil is supplied with two circuits to ground that are internal to the CDI module. Each circuit shows an inline resistor, internal to the module. No resistance value is given for either resistor. In order for the exciter coil to produce current flow to charge the ignition capacitor, one or both of these circuits must have continuity to ground.
One circuit is grounded through the neutral safety switch. The other circuit is grounded through the oil pressure indicator lamp and through the oil pressure indicator pressure switch.
When the engine starts and builds sufficient oil pressure, the pressure switch closes and the lamp illuminates. As long as this circuit has continuity, the exciter coil is able to continue to charge the ignition discharge capacitor and keep the engine firing even when the outboard is put in gear and the neutral safety switch goes open.
So, if the engine wants to die when placed in gear, it could be the ignition shutting down due to one or more of the following;
Low oil pressure.
Faulty oil pressure switch.
Faulty oil pressure indicator lamp.
Internal open in the CDI module's oil pressure indicator circuit.
Faulty connections or wiring between the CDI connector and oil pressure switch.
What page are you seeing that info on.
The only schematic that I can find includes the stop switch and the oil pressure switch, but not the neutral safety switch.
I do not see where the oil pressure switch keeps the motor running. It looks to me that the exciter coil is putting out voltage no matter what. I must be missing something.
I have had experience when the motor would not run due to a shorted out oil light (very rare). The circuit was acting just like a kill switch.
I am looking on page 96 under operating principles.
Puzzeled (As usual for an old guy)
That's my "info" and I'm making it up as I go
I'm looking at page 96 in my manual too. It is my opinion that the two circuits that are shown above the charging coil bridge rectifier are the oil lamp circuit and the neutral switch circuit. They aren't labeled as such but I don't see the engine stop switch on that diagram either. But, isn't the stop switch just wired so as to ground the positive side of the coil primary winding? If so, it wouldn't need a resistor internal to the CDI so that's why I think that depiction in the book is of the neutral switch.
Also, I don't believe that the exciter coil can attain a path to ground through the discharge capacitor or the thyristor. So, in order to begin "charging" and create a potential to charge up the cap, a complete circuit for the coil needs to be maintained through at least one of those two grounds.
I haven't tested my theory empirically yet as I don't have a running "oldie" in the shop at the moment. But, at least, I've got you hooked into looking at it now and if I haven't got it figured out correctly then I bet that you eventually will my friend Then, we can draw up a proper diagram to give to the guys.
This manual I have already has a bunch of changes relating to coil specifications that you had to straighten me out on once before. The book was wrong and you were right!
The one reason I do not think the neutral safety switch is in the schematic, is because there is no mention of it in the operational writeup. The neutral safety switch is discussed in the next section, but does not talk about how it is involved, electrically, in the starting of the engine.
Also, I would think the stop switch goes through a resistor and not directly to ground because that would put the exciter coil in a direct short to ground and the current (even though temporarily) would be very high. I would think that from a design point of view, it would be "grounded" through a resistor low enough in value to keep the cdi from functioning, but not too low for high current to heat up the exciter, eventually causing a failure.
Only conjecture at this point.
I will keep an eye out for a better schematic that includes the neutral safety switch. That should tie it together.
There may be something in the archives the explain the neutral safety switch when it was first introduced with the BF75 when it changed to a cdi.
Thank you for all your help, there was a lot of research that went into finding out how this system operates. Is it possible that the neutral safety switch is bad? I bypassed the switch by removing it from the bracket and leaving the wires attached. I trolled with this motor several hours over the weekend and it ran great. I have ordered a new neutral safety switch from my local Honda shop and it should be in this week. Your list of possible causes seem to be all related to oil pressure. My oil light is on when the motor is running and was always on when the motor died when put into gear until I bypassed the neutral switch.
Thanks Again for all your help
Well, you're welcome of course but, then again, I had selfish motivation in trying to help solve your problem. Also, it would seem that my theory about the oil switch and oil indicator lamp was all a bunch of hooey anyway. Your own experience proves that. If your oil light remained on when the engine was losing ignition then my theory just can't hold water.
The bad news is, though, I'm not sure your new neutral switch will solve the problem. I now tend to think that the ignition continuity is being switched internal to the CDI module, after the engine starts, via a solid state circuit using transistors not illustrated by the rudimentary drawing in the service manual. I should have known but I tend to "outsmart" myself from time to time. If that is the case, the module is probably defective. I don't know if they are even available anymore.
At any rate, I guess you'll soon find out. Let us know what happens and good luck.
I hope they can get one. It looks to me like the switch is backordered. Not a good sign.
It is possible that it is bad. Have you tried adjusting the shield?
Thanks for putting up with Jimmy's and my theorizing. As you can tell, it really bugs us not to know how something as simple as this cdi works.
I have the same outboard - same exact problem and Mr. Google found this thread - which was very useful to me.
Turns out that my outboard ran fine until I had to get at the rectifier and had to remove the Nuetral safety switch assy. When I put things back together, the output ran great as long as not in gear. Oil pressure light and system seemed to also work perfectly.. But when I would put it in gear, it would die very fast.
I tried to do something similar to what the OP did - see if the outboard would run with the switch assembly removed. The outboard would not start but I did get a nice shock when I touched the switch assembly housing when I pulled the starter rope..
On my outboard, there are a couple wires which I guess are some sort of ground that connect to the nuetral safety switch housing. When I examined things, I found paint or something like that where the nuetral safety switch grounded to the outboard chassis. I cleaned this up so that the nuetral safety switch chassis now made a good ground to the outboard chassis - put the bolt back in place.
Outboard ran perfectly after I did this.. no problem at all switching into either forward or reverse. So I think at least in my case, I had a poor "grounding" electrical connection between the nuetral safety switch housing and the outboard chassis.
Last edited by walt_h; 09-07-2011 at 11:42 AM.
Thanks for taking the time to post your findings. This system and it's "explanation of operation" in the service manual still confounds me. The book just doesn't describe what changes when the engine is running so as putting it into gear doesn't kill the ignition. I'll figure it out someday. At least you figured yours out and shared it with the group.
Thanks again, and WELCOME ABOARD!
duplicate message - delete
Last edited by walt_h; 09-07-2011 at 11:18 PM. Reason: duplicate - deleted
I of course spoke too soon about solving my problem... but now think it may have been due to a blown rectifier in the charging system.
Note.. I did not mention this before.. but I had just put back in a known bad rectifier - why?? good question.. but mostly so that I wouldnít lose it.. Also, my outboard is a 1990 BF8 (8 hp).
Below is with the known bad rectifier connected in the original wiring..
I can start the outboard - runs fine and the oil light is on.
The neutral safety switch has two metal ears and when I rotate the shift lever in either direction but not enough to actually shift, the lever will get to some point where the oil light goes off - and the engine dies.
I am fairly sure that the light goes off and the engine dies when the metal "ear" is in between the neutral sensor. Iím fairly sure the metal ear in the sensor slot correlates with the engine dyeing. Other than this, the engine runs perfectly.
It seams that some other "circuit" is in parallel with the neutral safety switch and the other circuit is what is supposed to keep the ignition working when in gear. I checked the neutral safety switch and it is a short when in neutral (i.e., no metal ear in the slot) and it becomes an open when the metal ear is in the slot - i.e., when in gear (F or R).
Remembering about the bad rectifier, I disconnected the wires to it - then assembled the neutral switch again. Now.. everything works fine again. Why this weird interaction.. donít know and Ill have to keep checking. But it seems that the problem may somehow be caused by the bad rectifier. FYI, I canít remember the details from when I checked the rectifier (was about four years ago) but I believe at least one of the diodes looks like a short.
FYI, I think the previous owner had disconnected the charging system from the battery while the engine was running and blew the rectifier (in a sailboat and he had a switch between the outboard and the battery). I had checked the rectifier in the past in a lab at work - it was blown.
Problem is still not solved.. I started the outboard this morning (cool morning early Sept in Denver) and still have trouble with the neutral safety switch.
What happened this morning (with the bad rectifier disconnected - should be no problem since this is only used to charge a battery and there is no battery in this case) - I started the outboard no problem but then had the same problem - when the neutral safety switch opens, the outboard stops running.
I then let the outboard run about one minute - then I could put it in gear. However, I let it idle in Neutral again - and then the neutral safety switch once again would kill the outboard when put in gear.
The neutral safety switch is just a "logic" input to the electronic ignition module. I there any good reason to not just SHORT the two wires to the Neutral safety switch? I don’t have electric start and am fairly sure this will solve the problem.
And.. I don’t want to start replacing things like the electronic ignition module without understanding why it’s making the decision to shut down the motor based on the neutral safety switch.
Yes, I think that shorting the neutral safety switch wire to ground is going to be the ONLY way for you to operate the engine. Here is why I THINK (don't know for sure) that:
My latest theory *(guess) as to what is going on is that, as you stated above, the neutral safety switch circuit to ground is in parallel to another ground to keep the ignition firing. The neutral switch ground enables the engine to be started but then there is a "switching" to the parallel ground once the engine is running. I believe (don't know for sure) that the switching takes place in the ignition module.
Therefore, I think that the engines that behave in the way yours is behaving now have bad "switching" circuits in the ignition module. Running the engine from the neutral switch might be the only way to keep the engine running now without replacing the ignition module. And, I don't think you can still buy a new direct replacement.
I also think that they had so much trouble with these back in the day, that is why this system isn't used anymore. The newer pull starts use a mechanical lockout to keep you from starting the outboard in gear. That's my new story and I'm sticking with it until, once again, somebody proves me wrong. Wouldn't be the first time.
Done... on my outboard, there is a two wire set that comes from the CDI module and plugs into a set of wires going to the nuetral "cause a problem" switch. I just disconnected the wire set and plugged the two wires together that go to thd CDI module (ie, I shorted the two wire set going to the CDI). This is the same electrically as what the NSS did when in nuetral. There was even a male and female connector on this set, made it easy.
So far, this seems to have completely solved the problem - but I can start the outboard in gear which probably has some safety risk??
Thanks for taking the time here..
I may have missed it..in my old age...but did you ever adjust the neutral safety switch, so that it operates properly in neutral as well as in gear?
If everything is in adjustment....as you said, the cdi probably has a bad circuit
Yeah, this circuit is a mystery. It must be some sort of "latching" circuit in the CDI pack. Unfortunately...no good circuit diagram to explain it.
Yeah, you really don't want to have that puppy start up in gear if the throttle is open. I do repairs for a rental fleet and the owner is "old school". Against my advice, he wants all the start neutral lockouts disabled so that the customers won't call for a rescue when they can't figure out that they left the outboard in gear and can't get it started. Accidents waiting to happen. I am really amazed that they haven't made the evening news yet.
So, be careful!
"A day spent in observation at a launch ramp will teach a person many life lessons about what not to do".
Last edited by jgmo; 09-09-2011 at 11:00 PM.