[BIZNAWICH]

Hi folks.

I really need a little help if it can be spared, please: I have an EX800 (Honda) generator: SERIAL# PO2835 mid/late 80’s +/-, runs smooth @3600rpm (checked), nothing at the receptacles.

Circumstance:

1: given to me by my brother 11-12 years back because it wouldn’t start (haven’t touched it since)

2: storage condition- no gas (at all), brand new oil and plug…no use on either (wouldn’t start)

3: checked for spark, compression and with a small bit of gas had only 2 of 3…NO SPARK

4: removed front panel and began checking for shorts, opens with VOM and visual condition. Found damaged low oil indicator reset switch glued and duct taped together.

5: disconnected 4 wires from L.O. reset switch> 1 black, 1 green routed to engine switch and 2 blk/wht wires from broken reset switch/button and removed switch.

6: installed (for safety) a 5-amp spade fuse between the black and green wires routed to engine switch then soldered a “bullet connector” to the ends of the 2 blk/wht wires to connect them together

7: unplugged both wire harnesses at power head end of generator (1 with 6 wires and 1 with 5 wires) as well as the “fuel rod” going to petcock from “on/off” switch to make removing front panel easier

8: found no obvious shorts or grounds with VOM or visually. Checked contacts on low oil “sending switch” bolted over hole in engine block and there WAS continuity between them

9: checked for spark again to see if taking broken low oil reset switch out of the circuit made any change and apparently it did…THERE WAS SPARK at the plug

10: reattached front panel (fuel rod and wire harnesses) Turned engine over and had NO spark (again)

12: I reasoned the only electrical I messed with (disconnected) were the 2 wire harness plugs coming from the power head…so I unplugged both again…got spark and the engine started; the (green) PILOT LAMP lit up on the front panel when it did.

13: plugged both wire harnesses in one at a time…the smaller size plug (but with 6 wires) did not cause the engine to stall: the larger plug (with 5 wires) however, did cause stalling.

14: I used a jumper wire to determine which tab in the plug caused the stall and turned out to be the green wire (ground according to the schematic)

15: I’ve checked all OHM resistance readings with my Volt Ohm Meter including brush terminals and sub-winding and all are within spec according to what information I’ve downloaded from the internet. I can't locate enough reliable info to know what is supposed to read what on my VOM except OHMS and continuity.

Folks… First of all, thank you for reading this far and second, I really need a little advice on what to look at next: I’m only fair to midland with electricity/electronics…"everyman" skill level mainly and I’m stuck. Any help would be very much appreciated.

Thanks,
Bruce J
(BIZNAWICH)

 

[GenKnot]

I would suspect something wrong the oil sensor circuit (oil alert unit switch, oil alert switch, or oil alert timer unit) as reconnecting the 5-pin connector would supply ground to that circuit.
Anyone else have another idea?

 

[BIZNAWICH]

Thank you GenKnot for the reply.

I too reasoned that it must be something by way of engine protection switches and resets etc. that was causing the stalling considering the pilot lamp was illuminating while running (indicating it was generating power) however, I don't have the precise technical info to properly "test" potentially bad switches or connections. I can check resistance (OHMs) according to what specs I can locate and determine open/closed switches as well as obvious shorts, but I don't know if any of that is supposed to be.

I managed to fix (straighten out the engine switch that was making lousy contact when I slide the on/off slider on the front panel to on and as I stated above, I made "through" connections where the low oil reset switch was; assuming the normal switch condition was closed with oil in the sump.

I also replaced a "melted" ground wire that connected the DC grounding terminal (not the negative) to the back of the receptacle strip; that must have been caused by something "not right".

I have assumed GenKnot that the oil pressure switch is supposed to be closed i.e., continuity between the soldered contacts connecting the 2 blue wires on the top of it but I don't know if that's right...hence my overall difficulty.

I also have the schematic you posted above and am using it as a guide into my generator conundrum.

I really appreciate the response since I do want to fix and use this little gem . In any case someone could get some productive use from it.

Bruce Jennings
(Biznawich)

 

[GenKnot]

I am not sure how the oil sensor circuit works. Some of it is clear, and some not. But, let me see if this helps (this is what I think is correct)...

The press-to-reset Oil Alert Switch needs to open...the Black and Green wires. There be continuity between the two B/W wires.

Since the pilot lamp is lit, there should be the same power at the Y (I guess that is Yellow) and Gray wires to the Oil Alert Timer Switch when the gen is running. Each of the two Blue wires from the Oil Alert Unit Switch should also show continuity over to the Oil Alert Timer Switch (test these two wires with unit not running).

With the unit running there should be some unknown AC voltage between the Gray and B/W wires on the Oil Alert Timer Switch similar to the pilot lamp voltage.

So now, the question is should the Oil Alert Unit Switch be open or closed when sensing full & low oil levels. I guess some testing of that might be necessary to find out which. Maybe tilting the gen (not running) towards the side without the switch would open & close the switch.

It appears to me that the Oil Alert Unit Switch would open (or close) on low oil level and the Oil Alert Timer Switch would begin its countdown until it thinks the gen should be shut off. At that time, the Oil Alert Timer Switch would pull current thru the Oil Alert Switch causing it to pop the button and also close the switch between the Black and Green wires. Closing the switch between the Black and Green wires would shut down the gen.

Also, the gen should run with the 5-wire plug in place IF the Green wire from the Oil Alert Switch is unplugged.

 

[BIZNAWICH]

WOW! Now that's what I call system checking GenKnot!..thank you! I am going to print this post and follow what it lays out first thing tomorrow morning. I will let you know forthwith what happens

Bruce Jennings
(Biznawich)

 

[Dutchy491]

Yeppers….we gots some crackerjacks on here. Sure appreciate their input!!! 😉