jpover
Member
Any long term update on this one? I've been considering the mule (used or possibly new) and also Kubota.
I am habing a huge issue with my 4010 trans 4x4 that seems eeirely similar to what you are talking about.... i posted this in the "KAWI WIDERS" page but i am not getting any traction, do you have any input on what i have going on?Kawasaki does know of the "fix" for it, but it's multi-faceted. One must follow the steps.
1: try starting the engine without touching the throttle pedal. If you start it like an old carburetor, it ain't gonna idle (and kawasaki don't believe me on that...but it's absolutely true)
2: check the engine oil. If over the full mark, it's got hydrocarbon vapors in it and it WILL affect idle quality. Change it.
3:check engine compression. Should be up around 200 psi or more. If low, check valve clearance and adjust as necessary (.010"). Tight intake valves are common, and it causes pulsing in the intake manifold, which confuses the intake air pressure sensor's reading to the ECU.
4: check air filter, especially if the oil level was high. Replace it if it's oil soaked and/or dirty. It too affects idle quality.
5: clean the throttle body. Put a hammer between the gas pedal and the frame above it so that the throttle is "bricked" wide open. Remove the air intake hose from the throttle body. Grab your carb cleaner or throttle body cleaner (with straw). Start engine. It will be running about 4000 RPM which is fine (it's governed). Spray the carb/TB cleaner into the TB until the engine falls on it's face, let it catch back up, repeat this process until you run the entire can of TB/carb cleaner through the TB.
Usually that fixes them BUT every once in a while it doesn't. There is another workaround too but I won't go into it because it requires access to Kawasaki proprietary software, a laptop, and proprietary cabling and adapters-only available from Kawasaki to my knowledge. Real similar to Kubota but different, and not as functional.
93 octane fuel burns real dirty. I know, the makers want you to think that it "cleans" things, but in the combustion chamber it does just the opposite...it loads things up with carbon including the intake valves, valve seats, valve faces, exhaust valves, piston crowns/domes/dishes, etc. 87 octane is perfectly fine for a low compression Mule engine and it is generally recommended. Also the fuel filter should be replaced periodically, it's easy to do, and not very expensive but it requires removal and disassembly of the fuel pump module.
The root issue is application. The 620 engine was originally designed as a generator/mower engine. On that type equipment, it ran at 3500-3700 RPM all day long under a heavy load, which generated a good bit of heat in the cooling and lubrication system. Well on the Mule, the engine IDLES most of the time and has little if any load against it. Total opposite. Big deal right? Wellllll.....if the engine OIL can't get up to 200 degrees+, any combustion byproducts can't evaporate. Engine oil level rises, gets a bunch of fuel vapors in it, and then because of the closed crankcase vent system (sorta a PCV) the engine is now ingesting it's own oil and fuel vapors that have built up in the crankcase, which carbons up the valves and pistons even more, wears the valve faces/seats off, the clearance closes up, pretty soon the engine compression is down, so is power, it won't idle, the throttle body gets gummed up, the intake pressure sensor senses pulsing, and it just overall runs like poo. Additionally, a stuck thermostat will also throw a wrench into the spokes in that they stick OPEN, and the engine won't get hot. Easy to spot using the diag software and a laptop but only dealers have it (to my knowledge), it'll get up to about 130 degrees in the hottest part of the summer and level off. An engine with a good thermostat will get up to 215 or so then drop back to about 180 and repeat over and over again--assuming the fan works as designed and the radiator isn't plugged up with cow/horse/goat poo and/or mud, dirt, hay, grass, chaff, fleas, ticks, dirt dobber nests, carpet, or whatever else. I think I remember one that had a bunch of cat hair across it too, their barn cats slept up on the winch area and the hair that was shed got sucked up by the fan, got wet during operation outside, and turned into a nasty mush that restricted air across the radiator core.
What recall was on the TPS's? I don't remember any but I don't have time to watch every single bulletin that comes out either.
I really appreciate all this information.Kawasaki does know of the "fix" for it, but it's multi-faceted. One must follow the steps.
1: try starting the engine without touching the throttle pedal. If you start it like an old carburetor, it ain't gonna idle (and kawasaki don't believe me on that...but it's absolutely true)
2: check the engine oil. If over the full mark, it's got hydrocarbon vapors in it and it WILL affect idle quality. Change it.
3:check engine compression. Should be up around 200 psi or more. If low, check valve clearance and adjust as necessary (.010"). Tight intake valves are common, and it causes pulsing in the intake manifold, which confuses the intake air pressure sensor's reading to the ECU.
4: check air filter, especially if the oil level was high. Replace it if it's oil soaked and/or dirty. It too affects idle quality.
5: clean the throttle body. Put a hammer between the gas pedal and the frame above it so that the throttle is "bricked" wide open. Remove the air intake hose from the throttle body. Grab your carb cleaner or throttle body cleaner (with straw). Start engine. It will be running about 4000 RPM which is fine (it's governed). Spray the carb/TB cleaner into the TB until the engine falls on it's face, let it catch back up, repeat this process until you run the entire can of TB/carb cleaner through the TB.
Usually that fixes them BUT every once in a while it doesn't. There is another workaround too but I won't go into it because it requires access to Kawasaki proprietary software, a laptop, and proprietary cabling and adapters-only available from Kawasaki to my knowledge. Real similar to Kubota but different, and not as functional.
93 octane fuel burns real dirty. I know, the makers want you to think that it "cleans" things, but in the combustion chamber it does just the opposite...it loads things up with carbon including the intake valves, valve seats, valve faces, exhaust valves, piston crowns/domes/dishes, etc. 87 octane is perfectly fine for a low compression Mule engine and it is generally recommended. Also the fuel filter should be replaced periodically, it's easy to do, and not very expensive but it requires removal and disassembly of the fuel pump module.
The root issue is application. The 620 engine was originally designed as a generator/mower engine. On that type equipment, it ran at 3500-3700 RPM all day long under a heavy load, which generated a good bit of heat in the cooling and lubrication system. Well on the Mule, the engine IDLES most of the time and has little if any load against it. Total opposite. Big deal right? Wellllll.....if the engine OIL can't get up to 200 degrees+, any combustion byproducts can't evaporate. Engine oil level rises, gets a bunch of fuel vapors in it, and then because of the closed crankcase vent system (sorta a PCV) the engine is now ingesting it's own oil and fuel vapors that have built up in the crankcase, which carbons up the valves and pistons even more, wears the valve faces/seats off, the clearance closes up, pretty soon the engine compression is down, so is power, it won't idle, the throttle body gets gummed up, the intake pressure sensor senses pulsing, and it just overall runs like poo. Additionally, a stuck thermostat will also throw a wrench into the spokes in that they stick OPEN, and the engine won't get hot. Easy to spot using the diag software and a laptop but only dealers have it (to my knowledge), it'll get up to about 130 degrees in the hottest part of the summer and level off. An engine with a good thermostat will get up to 215 or so then drop back to about 180 and repeat over and over again--assuming the fan works as designed and the radiator isn't plugged up with cow/horse/goat poo and/or mud, dirt, hay, grass, chaff, fleas, ticks, dirt dobber nests, carpet, or whatever else. I think I remember one that had a bunch of cat hair across it too, their barn cats slept up on the winch area and the hair that was shed got sucked up by the fan, got wet during operation outside, and turned into a nasty mush that restricted air across the radiator core.
What recall was on the TPS's? I don't remember any but I don't have time to watch every single bulletin that comes out either.