Reluctant appreciation for EFI

G

GearHead36

Well-Known Member
A few years ago, I bought a well used ZTR with a Confidant EZT750, a twin cylinder 27HP engine with EFI. IMO, that was the worst part of the mower. The mower had all of the features I was looking for (fabricated deck, serviceable hydros, etc), but it had that #%#@%% EFI. I know how to fix carbs. Not so much with EFI. Since the engine seemed to run well, I bought it.

When I bought it, it needed several repairs. I did the minimum amount of repairs to get it into service, with plans to do a more complete service in the off season. That first season, on several occasions, when cutting tall and/or thick grass on hot days, the mower would lose power, and start belching black smoke. I thought maybe a belt was slipping under heavy loads. I'd hit the PTO switch (disengaging the blades), lower the RPMs, and it would start running smoothly again. I'd continue mowing, and it might do that again, or it might not.

In the following off season, I discovered that the cooling fins were almost completely clogged with oily dirt. I was amazed that the engine hadn't burned up. At this point, I had the engine out of the mower, so I did a thorough cleaning with a pressure washer. It ran well for about another 1.5 seasons, so I thought I'd dodged a bullet. After 1.5 seasons, it died when the camshaft gear disintegrated, I'm betting from running hot. While repairing this, I did a few other things to it, like replacing the head gaskets and main seal. I referred to the shop manual numerous times. One time, I noticed that this engine has an engine temp sensor. Hmmm. Thinking back to those times of power loss and black smoke... I'm sure now that it was the EFI system putting the engine in a "limp home" mode to save the engine.

So it's likely that the only reason that this engine is not a paperweight is the EFI system.

Now I DO like:
- It runs perfectly at any air and engine temperature, and any altitude. No worries about the AFR being rich or lean.
- When the engine is shut off, fuel delivery is immediately shut off. So there's zero risk of the crankcase filling with gas due to a leaky needle valve, and zero need for a fuel shutoff valve and shutoff solenoid.
- No choke, so no need to learn the 'personality" of the engine, and how much choke it wants. I have an older single cylinder Command Pro, and it definitely has a personality. And a fuel shutoff valve.
- Low carbon buildup in the combustion chambers.
- Better fuel economy. It has two 3.5 gal gas tanks. I can get about 8 hrs of running out of that, which is good for a 27HP engine.
- It's very easy to use. Easy enough for my wife, who mows the grass now with this machine.

What I don't like:
- It has a bunch of sensors. A failure in any of them would likely prevent the engine from running.
- I have no way of determining if a sensor is good or bad.
- If the EFI system has a problem, I'll be paying dealer shop rates and parts prices to get it fixed.
- A gummed up fuel system is WAY more problematic than a gummed up carb. This is not much of a concern in my case. It's my primary mower, and I always use E0.

#$%^@# I don't WANT to like EFI on OPE engines, but I have to admit, it most likely saved this one. Still... if I ever have to replace it, I'll likely go with something with a carb.

Does anyone prefer EFI over carbs?. I'm talking about an engine that runs well. Not one that needs repairing. How many would pass on a mower with a good running EFI engine?
 
GearHead36 said:
A few years ago, I bought a well used ZTR with a Confidant EZT750, a twin cylinder 27HP engine with EFI. IMO, that was the worst part of the mower. The mower had all of the features I was looking for (fabricated deck, serviceable hydros, etc), but it had that #%#@%% EFI. I know how to fix carbs. Not so much with EFI. Since the engine seemed to run well, I bought it.

When I bought it, it needed several repairs. I did the minimum amount of repairs to get it into service, with plans to do a more complete service in the off season. That first season, on several occasions, when cutting tall and/or thick grass on hot days, the mower would lose power, and start belching black smoke. I thought maybe a belt was slipping under heavy loads. I'd hit the PTO switch (disengaging the blades), lower the RPMs, and it would start running smoothly again. I'd continue mowing, and it might do that again, or it might not.

In the following off season, I discovered that the cooling fins were almost completely clogged with oily dirt. I was amazed that the engine hadn't burned up. At this point, I had the engine out of the mower, so I did a thorough cleaning with a pressure washer. It ran well for about another 1.5 seasons, so I thought I'd dodged a bullet. After 1.5 seasons, it died when the camshaft gear disintegrated, I'm betting from running hot. While repairing this, I did a few other things to it, like replacing the head gaskets and main seal. I referred to the shop manual numerous times. One time, I noticed that this engine has an engine temp sensor. Hmmm. Thinking back to those times of power loss and black smoke... I'm sure now that it was the EFI system putting the engine in a "limp home" mode to save the engine.

So it's likely that the only reason that this engine is not a paperweight is the EFI system.

Now I DO like:
- It runs perfectly at any air and engine temperature, and any altitude. No worries about the AFR being rich or lean.
- When the engine is shut off, fuel delivery is immediately shut off. So there's zero risk of the crankcase filling with gas due to a leaky needle valve, and zero need for a fuel shutoff valve and shutoff solenoid.
- No choke, so no need to learn the 'personality" of the engine, and how much choke it wants. I have an older single cylinder Command Pro, and it definitely has a personality. And a fuel shutoff valve.
- Low carbon buildup in the combustion chambers.
- Better fuel economy. It has two 3.5 gal gas tanks. I can get about 8 hrs of running out of that, which is good for a 27HP engine.
- It's very easy to use. Easy enough for my wife, who mows the grass now with this machine.

What I don't like:
- It has a bunch of sensors. A failure in any of them would likely prevent the engine from running.
- I have no way of determining if a sensor is good or bad.
- If the EFI system has a problem, I'll be paying dealer shop rates and parts prices to get it fixed.
- A gummed up fuel system is WAY more problematic than a gummed up carb. This is not much of a concern in my case. It's my primary mower, and I always use E0.

#$%^@# I don't WANT to like EFI on OPE engines, but I have to admit, it most likely saved this one. Still... if I ever have to replace it, I'll likely go with something with a carb.

Does anyone prefer EFI over carbs?. I'm talking about an engine that runs well. Not one that needs repairing. How many would pass on a mower with a good running EFI engine?
Click to expand...
I see very few EFI engines on customer equipment. I have a Vanguard EFI on my Ferris zero turn. I personally do not like EFI on outdoor power equipment and think it over complicates things.
 
It is an EPA thing. They think reducing the emissions from lawnmower is great and it is important. But they are overlooking is all the polluting jets we have. I remember when 911 happen and all the jets were grounded how quickly our air cleared.

And I haven't seen exhaust on vehicles to be white with ash for a long time now but most if not all have black oily ash.
 
Tiger Small Engine said:
I personally do not like EFI on outdoor power equipment and think it over complicates things.
Click to expand...
I completely agree. Mine's working great now, but if it ever breaks, it will be expensive. The only saving grace, IMO, is that I know how to care for small engines. I've bought a couple of new mowers in the past. On the machines I've bought new, I've never had to go into a carb, even on machines I owned for over 10 yrs. So hopefully this EFI system will keep working.
 
ILENGINE said:
Not so much over complicating things, as much as them making them over complicated, Why would you need canbus on lawnmowers.
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Because... reasons, you know. Kohler doesn't use canbus. They use K-Line (ISO 9141-2 / KWP2000 style) communications. Your question is the same though. Why does an OPE engine need K-Line?
 
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StarTech said:
It is an EPA thing. They think reducing the emissions from lawnmower is great and it is important. But they are overlooking is all the polluting jets we have. I remember when 911 happen and all the jets were grounded how quickly our air cleared.

And I haven't seen exhaust on vehicles to be white with ash for a long time now but most if not all have black oily ash.
Click to expand...
Agreed. I used to live in the Atlanta area. While living there, I learned that the pollutant measurements that govern what blend of fuel an area needs... was taken at the airport. The busiest airport in the world. So I had to buy more expensive fuel that I should have because of the airport there.

Another thing that irks me is that, with an EFI system, all sorts of data is available, but none of it is made available to the operator. An oil pressure light could be implemented. A temperature gauge. A check engine light. None of that is used to benefit the owner. It's used to satisfy the EPA.

I DO agree that emission controls are good for motor vehicles. I once took a business trip to China. This was soon after they had mandated the use of catalytic converters, but most vehicles didn't have one. I went through a tunnel in congested traffic, so I was stuck there for several minutes. I could barely breathe. So I agree that it's a good thing for motor vehicles, but I'm still not convinced that it's needed for OPE, and I'm especially not convinced that we need to ban ICE's in favor of electric motors.
 
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Dixie Chopper has used the EFI for years I mean back in the 2000's. Not had very many problems with them. Know there has been a lot of changes in the systems since then. Most problems were in the O2 sensors. Had one where the heat sensor and the wire running to it was grounding out on the metal baffle under the blower housing. Rather than replacing the wiring harness or trying to splice the wire and run the risk of it doing the same thing again. I split a piece of tigon fuel line; split it open and zip tied it over the wire. Wala still running today.
 
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