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HELP B100 oill lamp

r8rdrew

New member
"I just bought a early 80'

"I just bought a early 80's Montgomery Wards seaking with I believe the same era Honda b-100 10hp. I had it runnung ok, a minor fuel problem, mostly i think it was a leak. It would run fine for awhile then it would seem like it was losing the prime on the fuel tank. So I replaced the entire fuel set up and now it wont start. I did notice a bit of smoke for about 8-10 seconds when it was running, but it did start again after that, and ran ok. I have checked the plugs, the lower cylinder has some oil, the top is ok.
After taking it home and replacing fuel line and new hose clamps, i primed it nice and tight and NOW IT WONT START.
I noticed the oil light, is lighting up while pulling the start cord. I dont know if this is normal as I use it mostly in the daytime and cant tell if the light does that normally. I checked the oil level it was at around 500. So I added oil to around 700. That means it only had about half the compacity that it was supposed to. I dont think i fried the motor, I think something needs to be reset, (I hope). The light still comes on while trying to start it. For the life of me I cant get it started, when it used to start 1-2 pull.
My questions are:
-Is there a reset for the light?(notlikely)
-Has the oil pump taken a Sh*t on me?
-I have the book and dont see a thermal switch.
-Is the light supposed to lightup/flicker at start up? until pressure builds up?
-Do I have TO MUCH pressure in the fuel system?

Please any help would be appreciated."
 
"Oil light on indicates normal

"Oil light on indicates normal oil pressure.

Too much 'squeeze' of the primer bulb could have flooded the carburater.

Most likely just some 'crap' that got in the carb as a result of the line replacement.

Get some Alcohol Solvent and an aerosol 'Canned-Air' and carefully and thoroughly disassemble and clean your carb, there is also a tiny screen/filter where the fuel line enters fuel pump on cylinder cover.

You can still download the BF75-100 Owners Manual from Honda website.

A Honda BF75-100 Shop Manual would be a good investment."
 
"Yeah i have the book. I think

"Yeah i have the book. I think I may have lost spark. I tried all the ohm testing for the pulsar coil and the primary. They show good continuity. I am stumped as to why the spark may be gone after running so well. Maybe the rectifier??
The fuel is pressurized to the carb. The previous owner said the carb was a fresh rebuild. The screen at the fuel pump is clean, except for the 3-5 microscopic partical of sand and what not. I tried to find spark today but couldnt tell as I have to work on it in the bright sunlight. I am waiting another 20 min or so on the west coast till dusk to check again.
I did notice some oil in the galley below the pulsar coil under the (cam) pulley. I cleaned.
Basically I have cleaned and tested all components and determined that it maybe the rectifier? Is this a common or likely problem? It does seem to have its hands involved in alot of the electrical system.
Is there a way to test the rectifier?
Am I looking in the right direction with the electrical? or should I look at more of the (obvious) change with the fuel line. I only changed the top half of the fuel hose(1 foot or so), the bottom and the bulb are new. I also put hose clamps on the internal fuel lines from the pump to the carb, there was none.
The bulb has good pressure now and doesnt seem to bleed off air anymore. Is that a good thing?
I also have a bad cap on the fuel tank. I ordered a new one because the top was cracked off, and the pressure switch/valve was on it.
Thanks for any help."
 
"Rectifier (finned compone

"Rectifier (finned component under shift rod) is Only used for the DC Charge outlet, has nothing to do with ignition or spark.

(Test for it is just a diode check accross the four wires, continunity or current flow, in one direction, but not in the other.)

Two coils under flywheel, one to rectifier and other to the CDI on top of the intake manifold.

Check the Ground Continunity from Coil plates to engine frame, it is all through the phillips head screws to the hidden nuts on the engine block.

Just before ordering a new CDI, I found several of its wires 'rotten' within their insulation.

Soldered some new wires from near the CDI through to the connectors and restored spark.

Another time, it was the ground wire from the CDI had broken off the bolt at the 'neutral switch' over the shift assembly.

It is best to look back at area just worked on when new problems arise, but disturbance can cause electronic issues to appear after other work.

If you confirm spark, squirt a little starting fluid in carb, this will run briefly with a clogged carb.

Your bulb pressure should not bleed off."
 
"I dont have spark. I check th

"I dont have spark. I check this evening. A little understanding first. Lets see if I have it right so far.
First the magnets on the flywheel pass the coil windings creating electricity, one sends power to the CDI, that gets its direction from the pulsar coil to send power to the ignition coil and the plugs, right?
The rectifier gets power from another coil on/near the flywheel? for the dc charge? Is that so you can charge a trolling motor battery or run lights?
I checked the wires and reconnected all of them. i cleaned the pulsar/timing coil from over flow oil leak. I removed the flywheel to look at the condition of the coil on the top. if I remember correctly i only saw one coil with two wires, not two coils.
I checked the ground wires good and tight. the housing on the body of the kill switch is a little loose but the connection on the plug itself is tight.
Corrosion for a water vehicle is average, some color, a little teal (color) on the connections but nothing to corroded.
Can I pull the wire off the kill switch on the hot side, to see if I am not grounding out? Its just a deadman right? that could be a possibilty no?
What is the correct procces, and in the right order, to check for spark? If you would elaborate a little more on checking the coil and CDI?
What should the meter read in ohms whiletesting the coil? Do I connect one test lead to the coil windings the mounted plates, or the wires coming from the coil, and then to the frame? The coil under the flywheel right? Should i be pulling the start cord to get some sort of power for a reading on the wire coming from the coil? will i only get a reading out of one wire? what meter setting should i be using for this reading and what voltage should it have? I have a Fluke 79 Multimeter.

Also while I was having problems with the idle and running at full rpms, I noticed everytime I pushed on the primer bulb it would kinda flood out. I got it started again and some smoke came out, (not a whole lot)I think it was excess fuel, and not oil. But it did start again and get me back to the dock fine. It was hot and the hood was pretty warm to the touch and coudlnt hold it very long till you needed to set it down. Must be normal, there isnt much airflow for this motor, being sealed and all with the rubber gasket and the only ports being the breather case lines, the outlet for the DC power and the small overlfow holes at the back of the housing. this doesnt seem like enough air to cool it.
On that subject now. I have some yellowjackets and a few leaves down the hull of the lower unit near the exhaust pipe, maybe a half a cup worth, not completely clogged. The holes look free but the stuff is above the holes. I cant get a shop vac down in there to get them out. Is this a problem? I dont have a steady stream of water coming from either of those holes. I tested in a garbage can and no stream was coming out. but I do remember seeing some bubbles while in the water.
Am I supposed to have a steady stream?

Thanks for taking time out of your day to answer these questions, you have already been alot of help."
 
"Your understanding is correct

"Your understanding is correct.

Spark should be seen with plugs out and grounded to engine, with a pull on rope and shift in neutral.

There should be two coils under flywheel, the one with two leads (Blue) connect to the plug on Silicon Diode Rectifier's Blue leads. This would provide 5 Amp for lights, but not much for trolling motor battery charge.

The other coil has just one lead (Brown) that plugs into the brown wire from the CDI. Only test listed in Shop Manual is for 330 OHM's resistance (+/-10%) from lead to core.

The test for the Ignition Coil is for 8k OHM's (+/-20%) between the spark plug leads and 0.56 OHM's (+/-10%) from primary lead to core.

The Pulsar Coil should measure 120 OHM's (+/-10%) between the leads. The oil was probably just from improper storage (not on frame pads).

Testing the CDI requires a specific SANWA ELECTRICAL or KOWA SEIKI Tester and there are three different tables for different s/n motors with values between all eight leads.

I just tested continunity with a sharp needle at CDI to wire lead ends and had to solder in new Black, Yellow and Blue Leads that were rotten inside insulation for the inch or more at their ends.

The Kill Switch Lead (Black) just goes to ground when pushed.

The neutral switch (s/n 1,300,001+) is closed (Blue to Black/White) when shift is in neutral for starting.

Should not be hot to touch on cover and it is water, not air cooled. Main Air Intake is under lift handle on top rear of cover.

Primer bulb could flood the carb if you squeeze hard enough and would make black smoke..

Yellow Jackets (AKA Mud Daubers) could cause internal problems in leg shaft.

"Pee Hole" on side or rear of upper case indicates cooling water flow and most of cooling water goes down with exhaust into shaft housing.

The top two holes are idle exhaust relief and main exhaust is out same fitting with screened water inlet on front side."
 
"Sweet you have been a great h

"Sweet you have been a great help.
The nuetral switch, I cant find. It will start in gear also (when it was running). The only components I see is the shift lever is all metal, and linkages. no wires, except the jumble clipped above it, and the kill switch next to it. I dont see a nuetral switch, unless it is underneath the shaft.

So if i test the probes coming from the coil with the single wire I should see some sort of power surge while pulling the cord right? The blue wires are for charging not ignition, so test the Orange or Brown one?"
 
"Neutral switch (s/n 1,300

"Neutral switch (s/n 1,300,001+ and earlier s/n would not have it) is magnetic, there is a shield plate on the shift shaft with a notch in center (neutral) that allows the magnet switch to close.

This is located just below that jumble of wires clip and green CDI Ground Wire connects to that clip bolt.

The kill switch was moved out on the tiller with s/n 1,300,001 and above, since you have CDI your serial number is likely 1,2xx,xxx.

No spec listed for it, but have seen voltmeter needle spike on pull when connected brown/orange wire and ground."
 
"I have tried everything. I ta

"I have tried everything. I talked to a guy today and told him it got hot, he said dissconnect the oil pressure switch and see if i get spark. No spark still. The brown wire has a voltage spike when the cord is pulled on 'voltage DC' on the meter. He told me it should be getting 200 volts. I only read .5 on the spike. The plastic case on the plug coil is cracked around the bottom, shouldnt be a problem I hope.
Does this mean the exciter coil is bad? the continuity checked out ok.
I also took the lower end off and found that the impeller had sheared off all the fins. Just f*ckin great. The compression is still good tho.

Does anyone know where to get cheap parts for these?
They dont make the CDI anymore. Might need a exciter coil and for sure a impeller.
thx"
 
""<<The plastic ca

""<<The plastic case on the plug coil is cracked around the bottom,>>"
Could be swelling of core, the nuts on ends of mounting screws are just in slots of the engine case.

Did you run the two tests on that coil and check its ground?

Your exciter coil looks Ok. (from your test)

No clue on output voltage from flywheel coil, but 200 sounds high.

The fact that you were getting oil pressure light indicates that flywheel coil was putting out.

Used Parts; Here is One eBay Store that I had good result from:

http://stores.ebay.com/Bdurns-Inc-Marine

For New OEM Parts I have had a lot of excellent service from:

http://www.boats.net/parts/search/Honda/Outboard%20Engine/0/parts.html

Nice zoomable, printable parts diagrams on each parts page,

Above site also has very good toll-free telephone service."
 
Thanks for the great thread. I

Thanks for the great thread. I had the same problems with engine not starting after a tear down to fix a cooling water flow problem. After going through everything and rereading this thread it finally hit me that I had the broken ground wire issue. In twisting the head to work on it the connector broke at the neutral switch. Started on first pull after fixing that! Many thanks
 
"Andy,
You might want go to t


"Andy,
You might want go to the forum on this website that is for "other outboard motors" this particular forum is for Honda outboards."
 
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