5 hp Nissan 2 stroke- sat for years- looks new in/out- won't start

[K38Bob]

Motor sat in a garage
Kill tether is connected
Gas in tank
Good tension on pull rope- feels right
No cough/sputter- AT ALL
Spritz some carb cleaner into intake- no effect
Water pump works- you can see the stream while cranking
Under the cowling it all looks new- no corrosion on terminals
Pulled spark plug and grounded to bolt near there- no spark- spark plug clean- gap seems right ( we put it in and we checked it then)

Ok, the fuel gets the carb- pulled the hose- it runs out.
Pulled the intake- everythings clean
Pulled the carb and disassembled most- looks like new

So...I'm back to the no spark.....

What to do?
Thanks!

 

[StarGazerI]

Re: 5 hp Nissan 2 stroke- sat for years- looks new in/out- won't start

Hi Bob! I too have a 1986 Nissan NS5B and had similar issue on time. First go threw a few checks for me and readers. 1. carb bowl - you should see a screw at the bottom of the bowl. to access this remove rubber near the "push stop switch" you should see screw for bowl. Unscrew and see if gas literally poor?s out of it. Putting carb cleaner in air-intake will not unclog the bowl parts and needle could be stuck in closed position meaning off. Food for thought.
2. check to see that all wires are connected properly located near the spark plug coil! Now disconnect the stop button wire. This will eliminate a bad switch where its grounding out the spark much like a lawn mower does.
3. Check flywheel for rust.. etc. I do think though, it would be best to take it into a shop and let them truly give it a complete check inside and out, also do all the tune-ups necessary to give you piece of mind.
Hope this helps some. StarGazerI
PS.. Spark plug is BP-7HS-10 or use BPR-7HS-10 they both work.

 

[K38Bob]

Re: 5 hp Nissan 2 stroke- sat for years- looks new in/out- won't start

Hi Bob! I too have a 1986 Nissan NS5B and had similar issue on time. First go threw a few checks for me and readers. 1. carb bowl - you should see a screw at the bottom of the bowl. to access this remove rubber near the "push stop switch" you should see screw for bowl. Unscrew and see if gas literally poor?s out of it. Putting carb cleaner in air-intake will not unclog the bowl parts and needle could be stuck in closed position meaning off. Food for thought.
2. check to see that all wires are connected properly located near the spark plug coil! Now disconnect the stop button wire. This will eliminate a bad switch where its grounding out the spark much like a lawn mower does.
3. Check flywheel for rust.. etc. I do think though, it would be best to take it into a shop and let them truly give it a complete check inside and out, also do all the tune-ups necessary to give you piece of mind.
Hope this helps some. StarGazerI
PS.. Spark plug is BP-7HS-10 or use BPR-7HS-10 they both work.

Hi Thanks for the reply.

Mine is newer- it came as a dinghy motor with another boat. Pics here.
http://www.box.net/shared/f7ocnqyv9b6sb4hpybhm

I'll check on the carb bowl. But when I took the fuel pump(?) off- gas ran out.

When I had the carb off the motor everything was bright shiny metal.

The wires look connected fine- the motor ran before storage. I've pulled a few on/off- all clean like new without corrosion

I did look at the flywheel and thought I was onto something when I saw a slight rusty spot where it passes the sensor- until I saw the big recess in the casting and some marks that look like timing marks- so I'm thinking the recess is what the sensor "senses"

It almost acts as if a "fuse" is blown- but I don't see any fuses.
:-(

 

[StarGazerI]

Re: 5 hp Nissan 2 stroke- sat for years- looks new in/out- won't start

Bob, at the end of this file (PDF) is an electrical diag. Im not seeing a fuse in it. Recheck your wires with DVM or ohm meter and also check stop switch is working properly with meter. all conections or joints. I do see a rubber access to the left of your gas on/off switch. StarGazerI
http://www.nissanmarine.com/tech_talk/pdf_files/Nis5B_5BS.pdf

 

[K38Bob]

Re: 5 hp Nissan 2 stroke- sat for years- looks new in/out- won't start

Bob, at the end of this file (PDF) is an electrical diag. Im not seeing a fuse in it. Recheck your wires with DVM or ohm meter and also check stop switch is working properly with meter. all conections or joints. I do see a rubber access to the left of your gas on/off switch. StarGazerI
http://www.nissanmarine.com/tech_talk/pdf_files/Nis5B_5BS.pdf

Thanks Stargazer! Lot of extra stuff in that wiring diagram.

All the wires run thru a rubber strap near the coil. I understand that the kill switch should be open electrically for the motor to be "on". In that rubber block all the wires seem to be in waterproof pull apart connectors- if they are pull apart- then pulling that wire (brown/black) should open the circuit.

I'll look into the rubber plug (in between the kill tether switch and the gas shut off valve) and the carb screw
Thanks!
Bob

 

[Sea Rider]

Re: 5 hp Nissan 2 stroke- sat for years- looks new in/out- won't start

You could disconnect both wires fron kill cord switch, check if you have a spark with that condition, If so, place back wires and with lanyard removed from switch pull/release with fingers the red knob several times, probably you have a bad contact inside. If the finger knocking doesn't help, replace switch.

Happy Boating

 

[pvanv]

Re: 5 hp Nissan 2 stroke- sat for years- looks new in/out- won't start

Assuming you have an M5B (photos look like it). If you can't get spark, and the plug is not getting wet from fuel, then you have 2 issues: no spark and no gas. Just because gas flows to the carb inlet does not mean the carb is working. If you disconnect the wires for the stop switch, you should have spark. If not, whip out your trusty Factory service manual (available from any dealer, including me) and troubleshoot the ignition system for a possible bad cd, exciter, pulser or ignition coil.

 

[K38Bob]

Re: 5 hp Nissan 2 stroke- sat for years- looks new in/out- won't start

Thanks everyone! Executive summary : Its the kill switch

Details:
I did remove the rubber plug between the gas shutoff valve and kill switch and loosened the carb screw- lotso gas.

Removed spark plug

Cranked, did notice increase smell of gas with cranking- convinced myself smell was coming from open spark plug hole

Set up spark tester (see pics http://www.box.net/shared/f7ocnqyv9b6sb4hpybhm
- only the final configuration shown after trial and error)- no spark- tried different gaps

Looked closer at brown wire connector and convinced myself it was a pull apart- it did with just a little more force than yesterday.

Spark tester shows spark !

Install spark plug.

Try to start- pull pull pull- nothing. Gee maybe it needs choke (doh!). Starts in 1/2 pull. Amazing.

Reconnect brown wire- engine stops.

Tried the manual exercise of the kill switch- no luck yet.

 

[K38Bob]

Re: 5 hp Nissan 2 stroke- sat for years- looks new in/out- won't start

Thanks everyone! Executive summary : Its the kill switch

Details:
I did remove the rubber plug between the gas shutoff valve and kill switch and loosened the carb screw- lotso gas.

Removed spark plug

Cranked, did notice increase smell of gas with cranking- convinced myself smell was coming from open spark plug hole

Set up spark tester (see pics http://www.box.net/shared/f7ocnqyv9b6sb4hpybhm
- only the final configuration shown after trial and error)- no spark- tried different gaps

Looked closer at brown wire connector and convinced myself it was a pull apart- it did with just a little more force than yesterday.

Spark tester shows spark !

Install spark plug.

Try to start- pull pull pull- nothing. Gee maybe it needs choke (doh!). Starts in 1/2 pull. Amazing.

Reconnect brown wire- engine stops.

Tried the manual exercise of the kill switch- no luck yet.

Ok- while trying to find this switch/part no online- I decided to take it out to see if pn was there. Gee pretty simply (see pic uploaded soon). So I pulled it apart- realized this is "on" position- started the engine no problem! I'm thinking now its just the rubber boot part that is sticking in the off position. It looks in good shape but has some aging.

Ok- I didn't think to short the terminals and shut the engine down by choking it and a little throttle.

Now realizing I could just pull the brown wire apart- I was ready. No start no start--maybe flooded. Pulled plug- oily. Clean it. Put the spark tester back on- yes we have spark. No start. A little carb cleaner and it catches and dies. Yes gas in carb bowl.

Ok- whats next??? So I tried a bunch of things. Decided I'm really not getting gas so take the carb bowl off and find the float stuck in the up position (and the bowl is dry (from all my draining). Pop the float free reassemble all is well- engine starts fine and I let it run for awhile.

So i put a screwdriver across the 2 terminals in the disassembled stop swith- Voila! Engine stops.

Get some lube for the rubber (be grown ups please) and reassemble stop switch. HHHmmm no start. Take another clip from another motor and wedge it in there under the clip- It starts! Pull the extra leash clip out- motor stops! Ok so the problem is the rubber part of the switch had shrinkage somehow ( no the waters not cold ) or wore away. Are there thicker clips? Is the rubber part a failure part? see pic for disassembled stop switch http://www.box.net/shared/70y5ry7ue9b5vqvl678x What are part numbers?

In looking at the rubber boot/metal cone piece- its tempting to cut down the spring to make up for loss of springiness in the rubber- or to drill out the screw hole to allow the screw to go deeper (same effect), or cut the screw down (same effect). or get a thicker clip or make one by combining 2!

THANKS!

 

[pvanv]

Re: 5 hp Nissan 2 stroke- sat for years- looks new in/out- won't start

You need 3D5068700M SAFETY SWITCH WITH LANYARD $47.73

You will want to go through the carb as well. It may free up, but it may also stick again.

 

[Sea Rider]

Re: 5 hp Nissan 2 stroke- sat for years- looks new in/out- won't start

Stop switches don't last forever, you have 2 internal oxided/corroded portions inside round metal plate with conductivity issues as seen on posted pic, assume you are going to fix it, if so, rotate round metal plate CW untill both nut contacts sits on new metal portion, clean or slight file both nuts too for good conductivity. Spray a good dosis of carb clean inside needle hole so as not to stick again inside or go for a full carb clean.

Happy Boating

 

[K38Bob]

Re: 5 hp Nissan 2 stroke- sat for years- looks new in/out- won't start

You need 3D5068700M SAFETY SWITCH WITH LANYARD $47.73

You will want to go through the carb as well. It may free up, but it may also stick again.

Thanks for the PN. Same answer from my local dealer (42$ plus Cali. tax). It seems like overkill when only the rubber boot is the problem. Plus its a bit of a hassle since the wiring harness comes with it. Everything looks like new on mine

I did clean the float and exercised it- feels free. I think it was an artifact from shutting it down by the choke.

 

[K38Bob]

Re: 5 hp Nissan 2 stroke- sat for years- looks new in/out- won't start

Hi,
The 2 spots on the cone (looks like a round plate in 2d) are really barely there- its still very clean , smooth. Since I took no care in orienation on reassembly, its doubtful they are in the same position. The 2 contact terminals are super smooth clean.

Remember its a failure to start problem on a closed circuit- no corrosion continuity issues.

The problem is getting the cone off the contacts to make an open in the circuit. Remember inserting a 2nd clip worked ( to lift the cone off the contacts). So the mechanical problem is that the black plastic rod (connected to the button that the clip slides under) is relatively too long since the rubber support structure is less "springy".

My backyard mod of the day idea is to remove the cone and drill down the end of the rod to make it shorter. My previous ideas were not correct when I realized its the length of the black rod is the problem.

cheers and thanks all!

 

[StarGazerI]

Re: 5 hp Nissan 2 stroke- sat for years- looks new in/out- won't start

If I understand you correctly.. Your switch is making contact all the time and you dont have a red plastic key for it to keep it running?? The plastic clip keeps the switch OPEN till removed.. If you are looking for a cheap way out just go buy an off-on switch at automotive store thats plastic or water-prof. and put in-place of old one. OR buy a key that fits your switch at any marine supply store.. Hope this helps! Drilling and all this work for a bad switch JUST NOT WORTH THE EFFORT..
StarGazerI Good Luck!

 

[pvanv]

Re: 5 hp Nissan 2 stroke- sat for years- looks new in/out- won't start

If I understand you correctly.. Your switch is making contact all the time and you dont have a red plastic key for it to keep it running?? The plastic clip keeps the switch OPEN till removed.. If you are looking for a cheap way out just go buy an off-on switch at automotive store thats plastic or water-prof. and put in-place of old one. OR buy a key that fits your switch at any marine supply store.. Hope this helps! Drilling and all this work for a bad switch JUST NOT WORTH THE EFFORT..
StarGazerI Good Luck!

Right. In fact, you can run with no switch at all. Many older motors did. You would either set the idle very low, so that you can stall the motor by idling down all the way, or leave idle normal, and choke out the motor to stall it. Likewise, you can get the factory switch with clip (I quoted the part above), which will preserve the "deadman" feature, or run any marine-grade momentary switch, and press it to kill the ignition. Don't overthink this simple repair.

 

[K38Bob]

Re: 5 hp Nissan 2 stroke- sat for years- looks new in/out- won't start

Guys, if you read upthread you will see that if I put an extra clip in the tether (more thick)- everything was fine except it was too thick and hard to use.

I realized also that I would need to also cut/grind that little phillips head screw and mill/drill down the plastic post. I was pretty sure it would work but if it didnt I couldnt restore to original.

So I went to the hardware store and found a spring for 70 cents that was close to original (thats whats behind the cone- it works against the springiness of the rubber body of the switch). I cut down some coils, stretched it and iterative a couple of times- the concept worked but not happy with end use.

I took a coat hangar and bent it around the shaft of the kill switch. Thinner than a 2nd clip. Worked great with one clip (start/stop). Now I know the thickness that works

Back to the hardware store looking at various parts- settled on rubber grommet for wire pass through in sheet metal. 44 cents. Took it home. Steak knife cut it in half (top and bottom identical). Slippled it over the button and pushed it down. Pushed in tether clip- starts! Pull out tether clip- stops! 21 cent fix- even looks good (black rubber on black rubber). Forces are same. And I have a spare.

Thanks everyone!

 

[pvanv]

Re: 5 hp Nissan 2 stroke- sat for years- looks new in/out- won't start

And at $75 an hour shop labor rates, you spent about triple what the actual part would cost. Of course, since you don't have to pay yourself, that's cool.

 

[K38Bob]

Re: 5 hp Nissan 2 stroke- sat for years- looks new in/out- won't start

And at $75 an hour shop labor rates, you spent about triple what the actual part would cost. Of course, since you don't have to pay yourself, that's cool.

Plus I learned a lot which can be reused
Kept a part out of landfill
and fixed it faster since it would take a week to get the part
I would have spent a similar amount of time taking it to/from a dealer (on their schedule as opposed to my schedule)
Kept 47$ for the part in my pocket and the cost of labor if the shop did it (troubleshooting and remove/install)

It really is a shame the only part that is failing (weakening actually) is the rubber boot and you have to buy the entire switch and wiring harness

 

[Frase24]

Re: 5 hp Nissan 2 stroke- sat for years- looks new in/out- won't start

Folks;

I just read through this set of messages and hope you can help. I have a 5 hp nisssan about 24 years old. When cold it starts and runs well, as it warms up it has an intermttent miss in its running. If you turn off the motor it will not start until it cools down. I have changed the plug, cleaned the carb and eliminated the kill switch. I am thinking now that it could be the coil, would anyone have any suggestions. Thanks.

 

[pvanv]

Re: 5 hp Nissan 2 stroke- sat for years- looks new in/out- won't start

This really belongs in a separate thread, as it's a completely different issue. However...

You may be overheating. How is the telltale flowing? When was the last time a wp kit was installed?

If you have an ignition part that is failing hot, that could be the coil, CD, exciter, pulser, or even the kill switch. Since you have disconnected the kill switch, you will need to do a proper and methodical diagnosis of the ignition system. Check ohm readings of all the ignition components, with a good analog ohm meter, guided by your trusty Factory service manual (available from any dealer, including me). If everything checks out when cold, then run the motor until it stops, and take readings again. You should then find the offending part.