Garden tractor acquisition

[kevm14]

I was doing some more research on these engines.

I found this manual. Page 4 has info on camshafts.

It shows that the 12.5hp engine (the ones I have) get their own lame intake cam but the 14, 16, 18 and 20 hp engines all share the same larger lift intake cam. Then for exhaust, the 12.5 to 18 hp use the same exhaust cam but the 20 hp gets a special higher lift one. I'm trying to figure out what makes the differences in the middle. At least from a cam standpoint, it seems like the 12.5 hp is uniquely restricted on power and the 20 hp engine definitely gets some unique hardware as well. But the 14-18 all share exactly the same intake and exhaust cams. So it would have to be exhaust or carb I think.

There was a 40 cid, 42 cid and 46 cid version I think. I think the 18 hp is 42 cid. Mine are 40 cid. If it is stroke, I hope the engine isn't actually wider...

The manual also shows some good info about setting the governed idle speed. I need to do an additional procedure on the Deutz because I just turned the throttle stop screw. Since the idle is supposed to be governed, there is an additional step. It looks like you bend a tab just like for high speed setting. The throttle stop screw itself is not supposed to be used to set governed idle and this makes sense because I remember when I originally set up my Simplicity, I could not drop the idle below a point and the governor took over. That is exactly how it is supposed to work.

[kevm14]

Well this is interesting. Apparently engine type numbers under 1100 are considered "pre-Twin II" engines and have some differences. There were three carb variants as well. The breakdown goes below type 1100, which is my Deutz. Above type 1100 but before a 1998 breakpoint. That's my Simplicity. And after the 1998 breakpoint.

Governed Idle
All Twin II twin cylinder engines equipped for remote control are equipped with governed idle. A detent in the equipment control provides governed idle when the equipment control is moved to the full slow position.

Pre-Twin II, twin cylinder engines equipped for remote control have provision for governed idle. Equipment manufacturer’s control may or may not provide a detent for governed idle. Controls with detents permit the governor to maintain engine speeds under light loads with control in the detent position. Moving the remote control beyond the detent to the full slow position overrides the governed idle and closes the throttle to the fully closed position to prevent engine overspeeding, in the event of governor failure.

Remote controls without detents will provide governor control, depending on control setting, at all positions except full slow position.

Interesting. I don't think the Deutz has a detent for governed idle. The throttle control seems identical to my Simplicity. But without a detent I guess you just guess. I'm not sure if that means in full slow, the Deutz will idle below the governed idle, while the Simplicity has no choice but to be on the governor no matter what. It is implying that to select a governed idle on the Deutz you may have to move the throttle like 1/8" or something.

In the charging section, it looks like the flywheel comes in small, medium and large magnet sizes. Mine are small magnet since they have the base charging system. If I don't change the flywheel, I could still upgrade to a 5A or 10A regulated charging system (stator + regulator). Why would I do that? If I wanted to run an LED lightbar or something like that. The 5A would give me 60-70W (minus charging power, which is probably around 25W, so up to 45W of lighting). The 10A would double that.

[kevm14]

These engines were made from like 1979 through at least 2000. Not all were cast iron sleeve. Some had regular aluminum bores. That sucks.

Model Series 401400, 401700, 421400 and 421700 have aluminum bore cylinders. That 18hp on CL says I/C so most likely that is cast iron sleeve. I would think most were. I would assume the non-sleeve ones were special low cost models...certainly Simplicity wouldn't have put that in their stuff anyway.

[kevm14]

http://www.pace7232.org/reporter/Jun%20 ... n_ends.htm

25 year run.

[kevm14]

Whoops, his reply was in junk.

This motor is good to go. You just have to change the starter which i have. Model 422707,Type 1214-01,code 9305075b.

Nice. It is a 1993. May 7th in fact. So 6 years newer than what's on the Deutz now. Model decodes to the following:

42 cubic inches. Mine are 40 so a little longer stroke I believe. I think the 12.5 to 16 was 40 cid. 42 was maybe 18-19.5. Then 46 cid for everything above that (20 and 21 I think). Not 100% on that but I think I'm close. 40 cid = 655.5cc. 42 cid = 688cc. 46 cid = 754cc.

Design series 2. Mine are design 4...
Crank/carb/governor designation type 7: Vertical shaft, flo-jet carb, pneumatic or mechanical governor. Same as mine.
PTO bearing, drive stuff and lube type 0: Plain bearing/non-flange mount. Same as mine.
Starter type 7: Electric 12V gear drive w/ alt. Same as mine.

I wonder what the design series difference is.

B The first digit after the displacement indicates BASIC DESIGN SERIES, relating to cylinder construction, ignition, general configuration, etc.

Hmm. Maybe that captures the front exhaust situation?

[kevm14]

Well I started the governed idle adjustment procedure. First I had to find a 1/8" rod so I used this. A drill bit was too long.

I adjusted the throttle stop to like 1,000 rpm with it held closed. Raised throttle slightly off the idle stop to insert the rod, and looked at RPMs.

Briggs specs 1,300 and Simplicity says 1,350 +/- 100 rpm. Tach was reading around 1,300 (1,309 in pic). Sooo....it's perfect already?

What surprised me is it seems to have a governed idle even with the throttle setting down all the way. Like if you manually hold the throttle closed to 1,000 and let go, it bumps itself up to the 1,300 or so. The manual implies that the older pre-1100 types (pre-Twin II) require a special detent setting in the throttle lever but maybe it was optional and Simplicity selected it even on the older engines. With the throttle stop set at around 1,000 rpm I guess that gives the governor extra push back room to close the throttle even further than the governed idle, if it wants to. I guess this would help governor response slightly? Dunno.

But yeah, all I had to do was back the throttle stop off a bit. I had it set to 1,350 before, which was evidently above the governed idle speed.

This engine is from 86 by the way so that 18hp one from 1993 is 7 years newer. The exhaust might actually route through the front of the frame.

Anyway, I checked full speed and it was still perfect at 3,4xx. I guess this is dialed in. I'll have to do my Simplicity in the spring.

In other news, I wanted to try the same experiment for a cold start that we did on Bill's big Simplicity. I turned the fuel on and cranked it at full idle, no choke. I let it do that for probably 10 seconds. Of course it didn't start. Then I opened the throttle slightly (as normal) and pulled the choke fully out. It only cranked for probably 2 seconds and fired right up. I don't know if the carb is emptying or if there's some other weird fuel/priming issue. Not sure I'm going to try to fix anything but I may experiment more and see if I can determine anything. I could pull the air box off and maybe check out the fuel situation while cranking or something. Ideally I'd pull the top of the carb bowl off to inspect the bowl after sitting. It would be interesting if the fuel somehow drains out. Not sure where it would go. Maybe on the ground if there is a small seepage somewhere.

What's funny about this is it still has the issue where if you don't shut fuel off, it overflows the bowl enough to back up into the intake and flood the engine/sump. Well, this small seepage is obviously a lower rate than that leak or else that would sort of resolve itself (while leaking fuel onto the ground of course). That's my guess anyway. Some kind of very slight leak at the bowl.

[kevm14]

So even though I like the idea of a 10A regulated charging system (it would charge better at idle, and allow me to connect lights directly to the battery and not have the brightness vary with engine RPM), there may be an easier solution. Honestly I think I could convert for under $100 plus some wiring BUT, there is this:
https://www.superbrightleds.com/moreinf ... ab/Reviews

The lights on my tractors now take like 12V AC from the stator. LEDs need DC. This just converts. So I could get like two converters and two of these lights:
https://www.ebay.com/itm/4PC-Light-Pods ... %7Ciid%3A1

And sure enough the reviews are full of people talking about using them on snow blowers. Most basic small engine charging systems with lights use AC.

Anyway those eBay lights are 30W each, under the 36W spec of the converter. And the AC light circuit is specified to do like 60-70W (nominally 5A @ 12W = 60W I guess) so they'd probably end up considerably brighter than what I have now. I don't know what the module would do at a lower engine RPM. Maybe dim. Maybe flicker. I dunno. But this might be a more sensible lighting upgrade instead of upgrading the charging system (which would allow me to skip the converters and just tap everything off the battery directly).

This is all annoying because I used the machine one time! I'm already contemplating engine upgrades, lighting upgrades, etc. I guess it's fun.

[kevm14]

But in case I do want to put together a 10A charging kit (works with my current flywheel - if I get the large magnet flywheel, it would do 16A out of the exact same hardware), here is what I will need:
Used 592830 stator, this one came off a Vanguard V-twin but it is the same as what I would need, and is only $28:
https://www.ebay.com/itm/18hp-Briggs-an ... Sw9xJd5oIT

Voltage regulator, P/N 845907. This one is used and only $19.81:
https://www.ebay.com/itm/BRIGGS-STRATTO ... 3629182066

After that I simply would need to wire the single 10A DC output into the wire that normally feeds the battery. Hopefully it can carry 10 amps. Now I'd be charging the battery at up to 10A, regulated (not sure what output is, maybe 14V?). Anything else I could hook up to either the battery or possibly the ignition switch. Not too complicated really. I could rewire my existing headlights to connect to switched battery power so they'd be bright all the time or add the LED lights (probably not both on only 10A - still needs to be able to charge the battery).

Maybe I should add the DC pigtail so I don't have to cut and hack as much.

P/N 692306. $13.94.
https://www.ebay.com/itm/GENUINE-Briggs ... SwONBZCj~Z

Yellow connector, P/N 399916, $4.99:
https://www.ebay.com/itm/Brand-New-NOS- ... SwDbhbouA5

So about $67 to convert. That is really not bad. This gets me 120W total theoretically (12V * 10A). Some goes to the battery but otherwise free to do various lights. And with this type of charging system, the lights would be battery voltage regardless of RPM so more like a car. And if I locate a flywheel with the large magnets, the output jumps to 192W total. Rear lights....oh yes.

The alternate plan is two of those converters @ $13/ea. So $26. Less power, less invasive install (mainly not having to pull the flywheel and swap stators). Lights bright only at max engine RPM. Not sure about reliability and I don't think these are weather rated. Less than $62 but honestly at these prices the money is not the issue. It's more...what do I want to do?

[bill25]

Wonder what the charging capacity is going to the battery. If it is adequate, you could just wire these to the battery with a switch, and maybe a fuse. The battery is already DC and in the operating range of these lights.

[kevm14]

You mean currently? Spec is 2-4 amps and it's really just meant to charge the battery. I don't know how much it could spare. It's kind of a constant current system. It just dumps some current and as the battery voltage rises, it draws less current. Not very sophisticated. The AC light circuit spec is 5A and all it has to do is two lights. Of course I could just hook up the lights since I have a big group 75 battery and use them sparingly but that seems a little ridiculous. If I had a volt and/or ammeter I could monitor battery draw and feel a little more confident about how much I could use the lights but if I am working I do not want to be playing games with the lights.

Here is what the Briggs repair manual says about the dual circuit alternator that both of my tractors currently use:

DUAL CIRCUIT ALTERNATOR
Dual circuit alternators use a single polarized plug with two pins. One pin is for charging the battery and the second is for the AC light circuit.

The dual circuit alternator provides DC current for battery charging and an independent AC circuit for headlights. The battery is not used for lights, so lights are available even if the battery is disconnected or removed.

Current for lights is available as long as the engine is running. The output depends upon engine speed, so brightness of the lights changes with engine speed. 12 volt lights with a total rating of 60 to 100 watts may be used. With lights rated at 70 watts, the voltage rises from 8 volts at 2400 RPM to 14 volts at 3600 RPM.

The current from the DC side of the alternator is unregulated and is rated at 3 amps. The output rises from 2 amps at 2400 RPM to 3 amps at 3600 RPM.

I will have to check mine again. At a spec of 3,400 I'm using some power but it was below that before. Not surprisingly the system is specified to provide 14V to a pair of PAr36 35W headlights. It is rated for 14V @ 3,600 rpm @ 70W but at 2,400 rpm output drops to 8V. That is a 1.75x reduction in power output for a 1.5x drop in RPM. More linear than I expected but still not linear. Point is if I do anything with my current system, I need to tap into the AC side and at least convert to DC with those modules. The charging side has no appreciable reserve for lighting (except maybe some markers or something).

That's why my options are repurpose and convert that 5A of AC to some LED lights which would replace the incandescent lights it has currently. Or upgrade to a regulated high amperage DC charging system and just enjoy the convenience of being able to tap into the battery as I desire and get full brightness all the time. I'd still probably have to disable the incandescent bulbs with the 10A system. The particular lights I linked from eBay would draw about 2.5A each, so a total of 5A. Considering the original charging system gave 2-4A, the new system is 100% DC so some would be required for charging duties - that leaves a 1-3A margin for additional loads. Which isn't bad. Maybe get a ~12W LED for the rear if I really need that.

To be honest I'm not sure I need any of this. The snow blower chute does block some of the light from the headlights. And more light is always good of course and even though my driveway is paved, you never want to shove a snow blower into something you didn't see. Also, near the house is fairly well lit. It's doing stuff at the end of my driveway (and occasionally turning around in the street) that may require a little more safety. Maybe just some cheap LED marker lights for the rear fenders (which I'm sure my current system could power) is all I need.

Like two of these for $6:
https://www.ebay.com/itm/2-LED-Red-Side ... f&LH_BIN=1

Found a video on charging system upgrade.

https://youtu.be/n-o7O2N8Dkc

This is kind of amazing. Briggs put out actual guidance on swapping around charging systems. I'm guessing this is more because you are swapping engines and may need to modify things to make the engine compatible with the equipment but it applies just as well to someone who just wants to change the charging system.

The following are alternator replacement combinations which require an adapter harness. All of the necessary components are shown.

My scenario is #3.

3. Original engine equipped with Dual Circuit alternator. Replacement engine equipped with 5, 9, 10 or 16 amp regulated system. Modify 393422 harness supplied with replacement engine by splicing in 399916 connector assembly. Connect to equipment harness.

And this makes perfect sense. The "equipment harness" shown is 2 wires. One is the positive for the DC charging circuit. The other is one side of the AC lighting circuit (they share a ground). So if you are converting to regulated DC, you simply splice both of those together and provide everything with the same DC power. The incandescent bulbs won't even know the difference.

I modified my conversion post to include that additional yellow connector that mates with my existing electrical system. This would convert so my headlights are bright all the time, and probably brighter than they were even at full engine speed before. Wonder if that upgrade would actually make the front lighting acceptable. Maybe I'll do that. Actually that would also enable the headlights to work with the engine/ignition off. If I didn't want that I think I'd have to put a diode in each of the wires (the one going to the headlights and the other going to the battery. Or just hope that the kids never flick the switch. This is certainly a sanctioned method as all of the diagrams in that PDF show direct battery connection for the lights if you have a regulated system (otherwise it comes directly from the AC side of the stator, which only works if the engine is turning, and generally quickly).

I'm not exactly sure where I'd put the voltage regulator. It comes with a short plug to connect to the alternator stator. Not a lot of options without extending the harness. Maybe upside down under the air box? Plenty of airflow there.

Still probably need those marker lights for the rear. I guess I'd wire them to the headlight switch if that isn't a total pain to access.

In other news, the headlights are an extremely common 4411 size (more widely known as PAR36). There are LED drop in replacements available.
https://www.ebay.com/sch/i.html?_from=R ... D&_sacat=0
https://www.ebay.com/sch/i.html?_from=R ... D&_sacat=0

I like these, 30 degree beam:
https://www.ebay.com/itm/PAR36-24W-Roun ... SwpoJbDmB-

Now I'd still have to convert to DC first because they'd work poorly on direct AC. But I could upgrade brightness with this approach even though the placement is somewhat an issue. But if it was I'd have to bolt those other LED floods onto the hood somehow. So brighter drop in LEDs might just produce enough light even with the chute blocking. The actual 4411 is a 35W bulb which is surprisingly high. So 70W total. I guess the 5A AC circuit is rated at 14V so 14V*5A=70W. 70W of LED light would be quite a lot. Or I could just get two of those converters, two LED bulbs (18W seems common which I assume is brighter than a 35W sealed beam) and call it done?

Oh man. No wonder why some of these listings kept referencing aircraft. Hilarious.
https://en.wikipedia.org/wiki/Parabolic ... _reflector

A parabolic aluminized reflector lamp (PAR lamp or simply PAR) is a type of electric lamp that is widely used in commercial, residential, and transportation illumination. It produces a highly directional beam. Usage includes theatrical lighting, locomotive headlamps, aircraft landing lights, and residential and commercial recessed lights ("cans" in the United States).

Aircraft[edit]
Main article: Aircraft landing lights
Aircraft landing (ACL) lights are often sealed beams that have a very narrow beam spread. They typically have a size of PAR36 or PAR46, and run on 28 V DC.[3] They have found some use in stage lighting as well.

But yeah, my tractors take PAR36 bulbs.