Honda 4514 Riding Lawnmower

[Gwbarm]

Just aquired this Honda 4514. I had heard of them and seen them but had never really looked at one. Amazing machine from the 90s.

It has a 14 HP inline 2 cylinder engine. A cute little fan like the old school cars had and a little radiator. It has a timing belt on the back of the engine running the cam and a water pump. Just like a miniature car engine with  electronic clutches to turn blades on and off. Pretty hight tech for the 90s not a small thing and built like a tank weighs in at 600 pds hydrostatic trans. I have found out that almost anything you have to do to it the engine has to come out starter timing belt water pump. Very expensive parts i think most got junked for that reason, i did find out they were built by John Deere except for the honda engine.

Does anyone here have any expierience with these. 

[Mech]

Sounds good Gw. My son's got a walk behind self drive honda and he's in love with it. I've worked on the self drives and they are a very nice machine. Easy start, super reliable, cut and drive real nice..  Just like honda quads.

Hopefully you will never need to take that engine out again after a cam belt and a service.

[Gwbarm]

It really wasnt that big of a job, but it seems as im getting older everything is a big job.

[Mech]

Haha..

[Gwbarm]

Got the starter working it was the soloenoid but it is actually attached to the starter loose connection crazy to have to pull the engine for that. I was prepared to replace the starter. Finally got it turning over with the key it has a hand parking brake like a car that has to be pulled to start the engine. Still wont start not even hit on starting fluid so its either bad out of time or coils bad.

[Mech]

Oh yeah Gw, get a wiring diagram. Drive-ons have safety features galore. You have to be sitting in the seat, with the blade disengaged, and with the cutters raised, in neutral, and it might start.. Oh, and full with oil..

And the hand-brake..  There might be more..

[Gwbarm]

Just got in from checking, just as i suspected a no spark issue but i was not sitting on the seat, im sure it is probably one of the switches, of course the story you always get running when parked.

[Mech]

It's a honda. It should be good.. Beautiful in fact..  haha

[Gwbarm]

Ill have to get some photos not bad just dirty

[Gwbarm]

Took afew shots to give an idea of what i was referring to:

 

[Mech]

Oh too cute. The little mower that could.

 

[Gwbarm]

Not high on my priority list , but found a little time to mess with it. Still no spark cant really get to the coil without pulling the engine or cutting out the battery tray its welded in. I read the instructions in the service manual and decided not to do any of that. It didnt make sense to me to unplug the red black wire from the coil then it doesnt get power.  It has no CDI but listed as a transistorized coil pack. Instead i decided to put 12 volts directly to the coil still no spark. To my surprize i put everything back together and it was sparking good. Started it on starting fluid several times and said im good to go.  Tried it 15 minutes later no spark. So i decided maybe theres a capacitor in  there that i charged up by putting direct voltage and it ran out, so that tells me no voltage is getting to the coil. I should have checked that first. Below is the troubleshooting chart and the wiring diagram, any thoughts.

 

[Mech]

I can't quite be sure I'm reading the colour, or role labels, on the combination switch contact diagram, but it looks to me like the wire coming from the ignition unit is earthed to kill the spark, and open circuit to run. That wire also goes into that multi relay called "combination relay". I'd suspect that relay can kill the spark if all the safety features aren't satisfied. I'd unplug that and spin the engine somehow and it should have spark.

[Gwbarm]

Sorry for the poor quality of the schematic i was afraid that might happen

[Gwbarm]

Looking through the service manual there is an ignition relay looks like a small CDI, i just have to find it not visible so it must be under the iinstrument panel.

 

[Mech]

That ignition relay will only be to power the lights , starter, horn etc; The spark is completely run off the stator.

That last picture is clear. You can print a single page, or whatever combination of pages you want, out of a pdf document, into a pdf document. Then they can be enlarged and searched etc easily. If you open a pdf and choose "print", then "print to file", then you can choose to print everything, the current page you are on, or any combination of pages, as a pdf document. It's what I generally do. Then you can post the whole electrical, engine, whatever, section.

[Gwbarm]

I will try that again, when i tried it the first time it wanted to print the whole manual

[Gwbarm]

Thanks for the Tip Mech, i think it worked

 

Honda4514HShopManual.pdf

[Mech]

Yeah it worked mint. I can magnify it right up and it's nice and clear, and, it only took a fraction of the time a jpeg would have to download..

[Mech]

After the pdf is made you can open them and rotate them and enlarge them and then save that as the preferred view and it opens like that after that.. Well i think it will, it does on my linux but I'm not entirely sure that they open like that on another computer..  In fact,..  could you tell me if this opens with the diagram horizontal..

Honda4514HShopManual.pdf

Cheers.

[Gwbarm]

No it opens vertical.

[Mech]

Yeah I suspected it might. Thanks.

It just saves that preferred view on my linux I suspect. I haven't started the windows system for literally years and can't remember if it works in windows.

[Gwbarm]

This project is interesting. It says in the diagnostic procedure to unhook the red black wire and see if it sparks, that is the only wire going to the coil, so how would it spark without power. I must be missing something. I checked the red black wire and no power there. I feed power directly to it and got no spark, then plugged it back together and it sparked. A little while later wouldnt spark again. 

[Mech]

I was imagining the coil must be right by the flywheel. Something like a chainsaw or small stationary engine has.. lawnmower in fact(of the walk behind variety).

The diagram shows the primary windings being a loop, with a small box in the circuit. The small box is doing what a set of points did on some small two-stroke bike forty years ago..  You'd know them well.

[Mech]

And the spark is going through both spark plugs at every firing, one on each end of the secondary windings, so both plugs need to be connected or neither will spark.

[Mech]

If it is close to the magnets on the flywheel, and in air,  check carefully for flakes of rust, or a pile/finger of rust, bridging between the magnet and the core of the windings. If a tiny piece of steel bridges the magnet to core it shorts the magnetic flux. No magnet no spark. The little slither of steel can flick up and down and make for intermittent spark at slow revs, and then either run, or kill the spark. I just use a dry rag to wipe rust or flakes off the magnet, which is where it generally is.

[Gwbarm]

The coil is right by the flywheel still not sure how it gets power the only wire going to it is the red and black

[Mech]

It's all internal to the coil. The magnets induce a voltage in the primary windings, the voltage is allowed to flow through the windings as a current, in the old days through a set of points, now days through a transistor, then, back in the day, when the points opened and the current stopped flowing the voltage flowed into a capacitor to help prevent the points burning, but also to increase the counter flow of voltage that developed in the primary windings as the induced magnetic field collapsed. Now days a transistor stops conducting instead of points opening, and there may or may not be a capacitor in there(I don't know). The collapsing magnetic field, combined with the voltage getting reversed as it goes back out of the capacitor, causes a high voltage to be induced in the secondary windings and so a spark. The wire coming out is only a kill wire..

Some of your old bikes will have a long core with a winding that spans two of four magnets in the flywheel, and a set of points. That winding either powers a separate ignition coil up on the frame somewhere, or in old machines it powers a secondary winding that's wound right over the top of the first(primary) winding I described. The second way with the secondary wound over the primary right there inside the flywheel is mostly on stationary engines and the separate coil is more common on newer bikes, like the sixtes and seventies bikes. Real old bikes, with a villiers engine say, they used the old system too.

Edited October 14, 2024 by Mech

[Gwbarm]

Excellent, you are so good with this stuff i appreciate your knowledge and expierience. I understand now why the manual says replace the coil , there is so much electronics there to go bad. I still may try to get an ohm reading, without pulling the engine very tricky to do, ,a very expensive part to replace 200+ may not be worth it. Its not a quad just a 35 year old lawnmower.

[Mech]

A Honda mower ..  

It sparked once. Checked it's earth ? That will be through the mounts. I'm assuming it will have an earth, but.. since the two plugs make an HT circuit, and the internal windings are all internal, perhaps it won't. If I was in there I'd clean the mount anyway I think, and check for the rust flakes.

And if the spark plug leads come out check them of course. If either plug lead had an open circuit then neither plug will spark. If a cap or lead had a short to earth then the other plug should still spark.

A lot of small engines use a similar system, and you might be able to find something made for the honda, or just a generic coil with built in controller. They (generic) can be got easily and cheap for small engines. They likely make them for twins.