Armed Polite Society
Main Forums => The Roundtable => Topic started by: Cliffh on February 17, 2021, 02:16:43 PM
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I've been thinking of replacing the stock carb on my riding mower with EFI for a few years. Back then there wasn't much choice. A quick search this morning shows there are actually choices now.
Has anyone had experience with EFI on mowers?
If I do retrofit, unless it's a setup designed for that engine & ready to run, it looks like there might be a bit of a learning curve trying to tune it.
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Won't you need a 02 sensor and a computer controller of some sort?
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Without actually looking a prices, it might be cheaper just to get a new engine that's outfitted from the factory with EFI.
Honestly, I'd probably leave things as-is. I don't know that you'll get any improvement with going EFI other than ease of starting. Downside is there's a lot more to deal with in terms of fuel system maintenance, winterizing, etc.
Won't you need a 02 sensor and a computer controller of some sort?
Not necessarily. A speed density system with canned programming based solely on RPM and displacement can be ball-park close enough to function decently. Maybe not perfect power or economy, but it will work. You will have to add something that provides an RPM signal. A self-learning system with an O2 sensors like you're talking about is preferred, though.
Brad
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What's the point?
What is your mower not doing that you want it to and think EFI will help?
Glancing at this kit (https://www.ecotrons.com/small_engine_fuel_injection_kit/) that's a lot of crap to hang on a lawn mower for some reason.
Don't forget you need to boost the fuel pressure to 45ish psi and install a regulator as well as intake air sensor, O2 sensor, ECU, and sundry.
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A quick search shows kits starting at well over $500 with most pushing at least a grand. A big fat Nope for me. Easer and cheaper to buy a new engine already outfitted with EFI. Cheaper still to leave well enough alone. Even if you have to buy a new carb every 3-5 years you're still dollars way ahead in the long run.
Brad
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Doesn't really have anything to do with EFI: this is the second engine in the mower - the first got about 350 hours. The mowers' got somewhere north of 800hrs now (450+ on this engine), and the engine's starting to show signs of needing to be replaced/rebuilt.
Both engines have been hard to start when cold. That's the main reason for considering carb replacement. Having the amount of fuel monitored and changed as necessary would be a plus also, this thing is run pretty hard. If I'm not mistaken, most EFI systems monitor engine temps and dump in more fuel if needed (which would help with engine cooling).
I've made a few mod's to this mower and plan to keep it, even if I do have to replace the engine a time or two more. With an add-on system I could move it from engine to engine, which might not be possible with an OEM system.
I've read of fuel injected chainsaws and lawn mowers:
https://www.kawasakienginesusa.com/engines/fs/fs730v-efi.html
https://www.cubcadet.com/en_US/efi-engines.html
https://www.stihlusa.com/products/technology/ms-500i/
Which leads me to believe that the systems can't be all that complicated and/or expensive.
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A quick search shows kits starting at well over $500 with most pushing at least a grand. A big fat Nope for me. Easer and cheaper to buy a new engine already outfitted with EFI. Cheaper still to leave well enough alone. Even if you have to buy a new carb every 3-5 years you're still dollars way ahead in the long run.
Brad
I'd seen those prices and yep, that's near to or more than the cost of a replacement engine. It seems to me that OEM wouldn't put a system on their product that cost quite that much.
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I have a older JD rider with a Kaw engine that can be hard to start with cold. I learned if you bump the starter a couple times it dumps fuel in the carburetor, then choke and it cranks it over.
Have you thought about a installing a oil cooler if you you are worried about running too hot?
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No I hadn't. Didn't even know they made one for mowers.
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No I hadn't. Didn't even know they made one for mowers.
Only if it's pressure oiled. If it's slinger oiled, no dice. Best way to ensure cooling on those is to regularly clean and inspect the cooling fins, shroud, and fan.
Brad
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Fortunately the oil system is pressurized. I keep the engine & deck clean, along with keeping the blades sharp.
The problem is timing. As in my timing for mowing. There are times when I can't mow as soon as I should and the grass is hood-high. And/or it's summer in TX. And/or the grass is wet. And (for now) I'm mowing 5 acres with a too-small mower (48", 27hp).
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I'm sure I can find some buddy's that do lawn tractor pulling that have played with them.
The only guy I know close right now is running a 434 cube Hillborn injected on his mower. The will cut the grass fast if you can make the turn at the end.
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That ought to drive a fair sized set of blades. =)
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https://m.youtube.com/watch?v=beXPpObKWFo
Brad
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No I hadn't. Didn't even know they made one for mowers.
Longer oil filter, i,e, more volume, if it will fit will help with cooling too.
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I did the larger oil filter on SB Chevy's running the Stock class, gotta get more oil where you can. Didn't even occur to me to use it on the mower... Saw a couple of utubes on the larger filters today, they mentioned the make/model of a couple that should work.
It'll fit, no problem. Even if I have to cut the hood a bit.
Speaking of oil, I've taken to doing an oil & filter change every 25hrs using Castrol 30w instead of the 50hr or so recommended. Oil's cheaper than a new engine.