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post #1 of 17 Old 08-18-2019, 10:55 AM Thread Starter
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Oman ignition

I am new and I have a question, I have a old Lesco Zero turn with a Onan p218 in it . I am on my second ignition module not counting the original I just put one in the other day and mowed with it when I shut it down it wouldn’t start again till it sat a while I have checked everything I could think of . Was wondering if the voltage regulator wasn’t working right a putting to much power through the module it would **** it down or burn it up ? I put a module in last winter and when I used it this spring it also quit . Also I have replaced the coil ,igniter , condenser . Any help would be appreciated. Thank you
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post #2 of 17 Old 08-18-2019, 07:26 PM
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Re: Oman ignition

Moved your thread to the Zero Turn area...you will get better response here

BTW....You should post an intro with your location, tractors you have etc. in the Intro area
thanks

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post #3 of 17 Old 08-19-2019, 07:23 PM
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Re: Oman ignition

I'm working on a P220 right now with Ignition problems and it also dying down after warming up. Here's what you need to do tests on.

One thing I've found with an Onan engine suddenly dying without warning after getting warmed up from 5-2hrs time is nobody has checked/tested the ROTOR to see if the plastic housing is cracked or the internal magnets have lost their strength.

I too have replaced coil, ignition module(control), condenser, voltage regulator, ignition switch, cleaned carb, new gaskets on intake/exhaust and other 30yr old parts to no avail of engine sometimes giving a carb/muffler backfire and other times just doing a die without warning.

Only thing I can think of is you haven't replaced the "rotor"(crank trigger ring). The housing is plastic and can crack, magnets lose strength(outer housing separates away from an inner housing that holds 2 very small, but strong magnets that trips the simple on/off switch inside the ignition module as the rotor spins over the module).

You've done about the same as I have and whether you find a broken rotor(trigger ring) or not, I'd replace it since it has many years of heat and usage on it. They're priced anywhere from $23 to $55 depending on seller or shipping charges.

I've done a simple test of the Rotor I have, to find it does pass the test, but without a new rotor to compare magnet strengths with, I'm replacing and hopefully I get the part this Tuesday.

Many people don't mention the rotor as it's a part that doesn't seem to go bad(unless obvious signs of breakage) often, so lots of people can get by with just changing out the ignition control and not have problems, but there's some of us that need to tear their engines apart twice, if they didn't replace that rotor the first time of teardown to find the engine wouldn't start..

I've really learned a lot about Onan's and how to test every electrical component on them and how they work.

Hope I've helped and cured the problem.
Del

1967 Cub Cadet 102-Kohler K241(10hp) Kept as original as possible.
1990 Kut Kwick CL20-60-Onan P220(20hp) Front deck/rear steer commercial mower
2003 Craftsman GT5000-B&S engine(24hp) Manual transaxle
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post #4 of 17 Old 08-19-2019, 07:45 PM
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Re: Oman ignition

Quote:
Originally Posted by poncho62 View Post
Moved your thread to the Zero Turn area...you will get better response here

EDITED:

Poncho62 I understand why you moved this thread to zero turns due to the mower type. BUT. It doesn't make a difference what mower an engine is on that is being asked about. It's about the engine and ONAN engines under the "P" designation(P216/P218/220/224/260) it's still the ONAN engine that needs help -- not the mower.

Problem with ONAN's is they're an older model of engine that most folks don't know how work or because they're expensive to repair or test components on. They're the commercial engine and surprisingly today's motor homes use an ONAN engine that still work in many ways the same as that lawnmower ONAN, and many parts from the "P" series engines interchange with that Linmar generator ONAN engine.

ONAN engines were put on Sears/Gravely's/Wheelhorse/Toro/Kut Kwick/John Deere/and many other quality brands, so please treat the ONAN's as a small engine repair question when asked, not as just a brand/style of mower question. It's easier to find small engine question, than someone having a rare mower and mods placing it in that limited area to not be possibly seen.

Just my observation. Thank you
Del

1967 Cub Cadet 102-Kohler K241(10hp) Kept as original as possible.
1990 Kut Kwick CL20-60-Onan P220(20hp) Front deck/rear steer commercial mower
2003 Craftsman GT5000-B&S engine(24hp) Manual transaxle
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post #5 of 17 Old 08-22-2019, 01:20 PM Thread Starter
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Re: Oman ignition

Thanks . I did change the igniter when I changed the module. I get the impression from searching that the module is heat sensitive. I have a lot of mowers I can use but I was mainly using this one to mow my area around my garage about 3/4 acre. I have had it for a while and have worked on it more than I have mowed with it. I should have given up on it long ago but I hate the fact that I canít get it running right. I just got a voltage regulator thinking that maybe it is sending to much current through the system and that is what is shutting down the module. I have a electric cooling fan I had taken off a van I have and am going to see if this helps the issue. I will let you know if either of these hep.
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post #6 of 17 Old 08-22-2019, 09:02 PM
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Re: Oman ignition

That's too bad Mags. One thing I decided to try on mine is doing a simple trigger light on/off test between rotor(ignitor) and module first as mine also didn't work when I changed the module. It can be done easily without any mower wires hooked up for test.

Get a taillight-any make(trailer) that has (2) wires protruding from it for easier testing, over just a taillight socket/light.

The module for this test requires a slight load of about 3-4 amp load like a coil gives, and a taillight works for this.

Have a good known battery to hook up for the test(it can be a motorcycle/ATV/or the mower battery).

Keep Ignition module(ignition control) bolted to the engine for ease and self grounding.

For ease of test, I marked the rotor with a sharpie pen once I found where the magnets were located to help determine when the tail light would go on, then off, as if it was firing the plugs.

Slip on the Rotor(ignition control igniter) onto crank shaft just over the raised area of ignition control to be sure magnets can trip the on/off module switch.

Hook up jump wire long enough to which ever taillight wire is going to bulb positive end. Make long enough that length of wire can reach positive(+) side of battery being used for test.

Now "T" somewhere into this positive wire and using another jumper wire go to the "RED"(+) wire of module. This red wire is what goes to the positive post of coil.

For the negative side of module(black wire) you need to run a jump wire to other taillight wire and negative side of battery

You now have full voltage to module as if it was hooked up to +/- side of coil to fire the plugs.

DO NOT GROUND THE TAILLIGHT. The module is already grounded to the engine and if you then ground the taillight also, it keeps the taillight constantly on and test won't work properly.

Remove spark plugs and now spin the motor over by hand and you see by the marks on the rotor that one magnet will trip the light ON and light stays on until you spin the motor enough to get to other magnet, which will then trip the light OFF, which stays off until it spins once again to the magnet that trips the module switch to again turn the taillight on.

Do this engine spin test for at least 3 times(spins on/off) to be sure module/rotor works properly.

NOW. if by chance you have the module off engine where there's no ground, you'll need to run the ground wire from the metal module mount to negative side(-) of battery and black wire of module directly to negative side of taillight wire.

Once you see that your rotor and module are operating correctly, remove all jump wires and don't touch the rotor. Install your flywheel and let it seat the rotor up against the back side of flywheel and torque the bolt down. This makes sure you don't install the rotor into the rotor pocket too deep where it either might fall off the crankshaft keyway or be too deeply back to not work correctly with the module in tripping it off/on correctly.

I did this procedure tonight once I received my new rotor yesterday and everything worked correctly and engine which I've been working on for 2 months now(mostly waiting for parts) and having to take it apart twice, fired up and ran perfectly. I let it run about 10-15 minutes in my mower shed at 1/4-1/2 throttle to listen for any stuttering, then moved mower outside and ran it around my yard for about 20 minutes under a deck load cutting some grass. Ran great. Would of mowed longer, but I'm having a belt guard mount rewelded and I didn't want the deck engagement belt flopping/vibrating too much and snap the belt. Then I'd need to figure a way in how to support and get a 400# front mount deck off, to remove the deck's drive shaft, just to get a new belt on. I have a very rare commercial mower made by Kut Kwick. Only 470 were built.

Del

1967 Cub Cadet 102-Kohler K241(10hp) Kept as original as possible.
1990 Kut Kwick CL20-60-Onan P220(20hp) Front deck/rear steer commercial mower
2003 Craftsman GT5000-B&S engine(24hp) Manual transaxle
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post #7 of 17 Old 08-22-2019, 09:35 PM
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Re: Oman ignition

I forgot. Yes the ignition control can be heat sensitive, but since most of these have been and still do work after 30+/- years, they're not too sensitive.

What you need to be sure of is that you haven't lost, removed, wasn't there, torn that small 1-1/2" x 3" thermal pad that's mounted to engine on back side of module. It's there for some "Thermal Protection". It does not provide electrical isolation.

If your missing the small thermal pad, they're $5 from Onanparts.com

Del

1967 Cub Cadet 102-Kohler K241(10hp) Kept as original as possible.
1990 Kut Kwick CL20-60-Onan P220(20hp) Front deck/rear steer commercial mower
2003 Craftsman GT5000-B&S engine(24hp) Manual transaxle
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post #8 of 17 Old 08-23-2019, 04:41 PM Thread Starter
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Re: Oman ignition

Thanks Del. I started it today and it ran for about 5 minutes and shut down , after it sat for about 20 minutes it started back up so I pulled in the garage and left frustrated. The fact that it starts back up after cooling down do you think the module is still good. I did put the thermal pad on the back of the module but there isnít much to it . Do they lose their effectiveness after a while ? Another thing is the voltage regulator , it has three prongs , mine has the two stator wires going on the two outside prongs And the middle one going I think to the switch , is that correct ? I did check the prong with a test light and am getting current to all three even with the key off, that doesnít sound right to me. Any thoughts. Thanks again
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post #9 of 17 Old 08-23-2019, 11:28 PM
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Re: Oman ignition

You should NOT be getting any voltage to the Regulator unless key is turned on, and then shouldn't do anything until after started. Especially the outboard prongs which come from the Stator that only sends out AC current, not DC readings.

Go to bottom of this info and read. After writing, it was something I thought of that ONAN's are notorious for if it has a oil sending sensor. It's a part of coil/ignition control testing I came across one day when I was having issues with my P220. It's a forgotten electrical item due to it being hidden.

The Regulator takes the Stator's voltage which is AC and it goes through the regulator's internal resistors/diodes and converts it to DC, which then goes back (there's a few detours along the way) to the battery for recharge.

When you start the mower, all power should go to ignition control and coil to fire the plugs. Once started then the Regulator kicks in after the Stator builds up the magnetic field to produce current.

Ignition control(module) red wire goes to positive post. Black wire goes to negative post of coil. Switch them backwards, and YOU WILL burn out the ignition control.

That isolator pad on back of module isn't much, but apparently does more than we think.

You might have a bad ignition switch. Switch should be marked on backside with--B(battery-this is a fused circuit, so check for rusty fuse contacts also), S or ST(start), ACC(accessories low oil alarm), IGN(ignition - goes into main wire loom where it branches to coil, starter or such). From this switch you'll also have branching off to other operating items like oil light, deck engagement switch, amp/hour meter or both, light switch.

Now of course if your switch has more posts, then wires will go to other points and switch will have additional markings.

You should have constant 12v to the battery post of switch(off or on). All other posts won't have current unless switch is On or in start position. Accessory side could have current also, but only in run position for any alarms or low oil pressure lights.

Not knowing your switch, it could be a 4-post(screw on posts) like mine, or it could be up to 6-posts(push on wire harness or individual screw on wire post) depending on how yours is wired.

Ignition switch needs tested to be sure it's not shorted out internally by doing a 12 volt check on all posts. Start in "Off" position first to rule out any stray voltage that shouldn't be there. Good. Now go to "On" position and test again, but this time branch out to any amp, hour meters. You should also get a low pressure/oil alarm or oil light. If not, check wires to find out why.

Almost forgot and this is an unusual one that I happen to find when doing a coil test from one of the forums. You'll need to remove the side tin the oil filter is on. If your ONAN has a oil pressure sending unit(found with (2) wires) on the oil mount block just above the oil filter. It's been known to shut down an engine due to malfunction. Replace it.

Apparently the oil sending unit cuts voltage to the coil, when it goes bad.

Del

1967 Cub Cadet 102-Kohler K241(10hp) Kept as original as possible.
1990 Kut Kwick CL20-60-Onan P220(20hp) Front deck/rear steer commercial mower
2003 Craftsman GT5000-B&S engine(24hp) Manual transaxle
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post #10 of 17 Old 08-24-2019, 08:19 AM Thread Starter
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Re: Oman ignition

Thanks Del, Since I have been having trouble with this I have always had power to the coil . There is a Onan trouble shooting on the internet with pictures , I am sure you saw it . Every time it shuts down I go through the test and always have power to coil but the test to run on the module where you put the test light on the side with one wire doesnít go off and on as the engine rotates like it should if it is working.
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post #11 of 17 Old 08-24-2019, 02:45 PM
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Re: Oman ignition

Had the exact same thing, except mine wouldn't start at all after replacing the ignition control. It would start, but only fire the spark plug when releasing the start switch.

When I took engine apart for 2nd time and I found one of the magnets from the rotor stuck to the stator. Magnet must of dislodged when I disassembled the rotor and put it back together while turning the rotor over in hands to slip the outer cover onto the inner sleeve. Ordered a new rotor and replaced and now motor works great. Now that I know where problem was, the old rotor still works in my opinion since the plastic isn't cracked/broken and has both magnets now.

I compared old rotor to new, and both seemed to have the same magnetic strength and both fit tight onto the crank shaft. But, that one magnet falling out made all the difference and probably me pushing it too far onto the shaft the first time, where it couldn't trip the ignition control.

You'll find by using another magnet close enough to the rotor magnets, that one of the rotor magnets will repel while other rotor magnet will attract. This is how it works on the ignition control to make it go off/on with the crank rotations.

Again, what ever you do. DO NOT put voltage to the negative(black wire) side of ignition control, OR by hooking control up in reverse onto coil terminal post. RED WIRE goes to + side(small terminal) post. BLACK WIRE of control goes to - side of terminal (large post). Doing so is a positive burn out of the ignition control.

If everything checks out with your tests, go ahead and replace the rotor. When new rotor arrives, place on crankshaft and do the ignition control test by rotating engine by hand. If it again doesn't read correctly, slightly pull rotor outwards on shaft and test again.

When I did my test with the new rotor, I aligned the rotors' front edge facing to be vertical(in alignment) to the raised portion of ignition control.

Del

1967 Cub Cadet 102-Kohler K241(10hp) Kept as original as possible.
1990 Kut Kwick CL20-60-Onan P220(20hp) Front deck/rear steer commercial mower
2003 Craftsman GT5000-B&S engine(24hp) Manual transaxle
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post #12 of 17 Old 08-25-2019, 04:47 PM Thread Starter
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Re: Oman ignition

Hi Del, Well I may have found the problem I went out today and started it tried to mow it ran for about 5 minutes and quit . It ran out of gas I didnít check it before I started it, after putting gas in it it wouldnít start till it cooled down. After starting it I pulled it into the garage and shut it off and noticed there was a little smoke with a electric smell to it so I disconnected the two wires from the stator and the other one coming from the voltage regulator. I started it and checked for voltage coming from the stator and got no reading. It ran till it ran out of gas maybe 1/2 hour. I put gas in it and I had to wait till it cooled but I ran it full throttle sitting in one place . When it cooled down it started and I let it run for 45 minutes and shut it off and it started right up. I need to replace the stator because the electric PTO will drain the battery. Am I safe in buying a used one? Also I would like to make sure it is wired right . Do you happen to know how the wiring goes from the stator to the voltage regulator and from the voltage regulator to the battery. I have a three prong voltage regulator. The stator must of had a short in it and was getting hot and shutting do the module. Thatís the longest I have had it running since Iíve had it. It is probably a early to mid 80ís zero turn . Thanks Del
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post #13 of 17 Old 08-25-2019, 06:11 PM
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Re: Oman ignition

Glad you got some progress Mags. You shouldn't have problems with a used Stator "IF" you request that the seller has tested it and will send along the test paper to verify that used stator is good as described, and will replace if it doesn't match what the ONAN testing lists. This is for your protection if seller is an individual.

I've found lots of companies on Ebay that sell ONAN parts where they say electrical part is tested, so you will have some protection with them if you use a credit card where you can do a charge back if after installation doesn't test correctly and some of the Stator testing can be done with the engine not running, but it needs mounted for proper ground.

The 2 wires coming off the Stator make no difference as to how they hook up to the Regulator, as long as the wires are hooked up only to the (2) outer most prongs of the regulator. The center regulator prong is to battery.

Stator puts out AC current, so wires won't know what outside prong of Regulator they're hooked to.

What makes the Stator make AC voltage, is when engine is running, Stator makes a voltage field from the flywheel as it spins around inside the magnetic field. Just like an alternator that sits in your car.

If your stator is the 20amp style here's the approximate spec voltage according to what I've found.

Engine -- RUNNING, both Stator wires disconnected at Regulator. Multimeter set to Volts AC.

Engine is Spec A: 21vac @ 1800rpm
41vac @ 3600rpm

Engine is Spec B: 29vac @ 1800rpm
57vac @ 3600rpm

Engine -- NOT RUNNING test. Both Stator wires disconnected from Regulator. Set multimeter to OHMS.

Using Rx1 scale on meter for detecting an open to ground in Stator(unit not running), connect (1) ohm meter test lead to one stator lead, connect other test lead to ground.

Reading should show and open (no continuity). If it doesn't the stator MUST be replaced.

If reading shows no continuity, measure the resistance of the stator windings by hooking up the ohm meter leads to each lead coming from the stator.

Stator OHM Readings: Spec A 20 AMP: 0.06 - 0.10 ohms

Spec B 20 Amp: 0.10 - 0.19 ohms

If resistance readings are as specified and windings are not shorted OR open, then low AC voltage might be due to los of magnetism. If so, the "blower wheel"(flywheel) needs to be replaced.

All specs given are for ONLY the 20amp stator.


Del

1967 Cub Cadet 102-Kohler K241(10hp) Kept as original as possible.
1990 Kut Kwick CL20-60-Onan P220(20hp) Front deck/rear steer commercial mower
2003 Craftsman GT5000-B&S engine(24hp) Manual transaxle

Last edited by TriumphMan; 08-25-2019 at 06:19 PM.
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post #14 of 17 Old 08-26-2019, 08:11 AM Thread Starter
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Re: Oman ignition

Del, How do I tell which amp the stator is ? They show for the motor. One is 35 and the other is 20 amp. I also need to check the stator again . I am pretty sure that this is the problem since it runs when it is disconnected ,it must have a short when it is connected the wires coming from it are very hot and there was a little smoke coming from that area when it is connected. Also is it safe to buy a used one or would you buy a new one ? Thanks for your help Del
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post #15 of 17 Old 08-26-2019, 09:28 AM
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Re: Oman ignition

Mags, if you read the first 2 paragraphs of my last communication, I laid out that that a used stator is ok to purchase, "IF".

To determine what engine options you have on your ONAN. The serial # and it's series spec letter/numbers will contain all the info, from year/month built, stator amps, and other info by following a "sales option code table" from the ONAN Parts Catalog that I happen to have.

If you give me your engine's serial number AND the series numbers and letters that follows the serial #, I can look up as to what your ONAN has, when it left the factory.

Del

1967 Cub Cadet 102-Kohler K241(10hp) Kept as original as possible.
1990 Kut Kwick CL20-60-Onan P220(20hp) Front deck/rear steer commercial mower
2003 Craftsman GT5000-B&S engine(24hp) Manual transaxle
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