The small engine guy here said you are asking for major repairs.
Why do they say to avoid single cyl, 17-20HP engines
- Thread starter ford46guy
- Start date
Well if you trust the small engine guy, why not ask him some specifics? And if you don’t trust him, why would you give it a second thought (or more business)?
Big singles are more heavily stressed, plus the V-twins have twice as many power pulses for roughly the same overall power which means the combustion “shock” isn’t as much, and smoother overall power delivery during heavy loads.
Also, it’s been YEARS since I’ve been in big singles, but most are still splash lubricated where most of the 20-24HP twins are pressurized. But, give your engine guy the opportunity to tell you why, and then fact check him
Big singles are more heavily stressed, plus the V-twins have twice as many power pulses for roughly the same overall power which means the combustion “shock” isn’t as much, and smoother overall power delivery during heavy loads.
Also, it’s been YEARS since I’ve been in big singles, but most are still splash lubricated where most of the 20-24HP twins are pressurized. But, give your engine guy the opportunity to tell you why, and then fact check him
My single cylinder 14 hp Kawasaki ran great for 23 years even with my neglect of cleaning the air fins. It finally had exhaust valve issues which a used head fixed easily. Use it almost daily hauling stuff around and doing the rough mowing this time of year.
The single cylinder engines are made to a price point. I think that's the reason for the large number of failures. Certainly, a large single is a vibration monster, and requires balancing tricks to run smoothly. However, as always, there is no reason an engine with any number of cylinders, of any size, can't be made with high quality parts and last a proper number of hours.
There are 70+ HP single cylinder motorcycle engines that last forever.
There are 70+ HP single cylinder motorcycle engines that last forever.
What does a whole replacement engine go for? I don't know, the 16.5 hp single on my 1990's LT1000 seems pretty healthy still? Lots of compression and decent power for a 42" deck. I'm not looking to replace it anyways, does the job.
I assume he must be referring to the Briggs Intek single cylinders, and he would be correct. If he means across all brands, then he is mistaken.
I understand the engine doesn't fall in the 17-20hp range but my Kohler 15hp in my JD LT150 runs great and has enough power for the mower and snow blower attachements.
Just my $0.02
Just my $0.02
Yes the problem with the Intek is the head gasket. There is a large gap between bolts at the pushrod box. They blow regularly at that point. Our R/C club bought a meticulously maintained mower with the Intek 19 from a member leaving the area. It blew the head gasket the 4th time we used it. It was $220+ to repair and we were told to expect to have to replace it about every 200 hours.
Ed
Yes this is likely a slam aimed at Inteks. They certainly have a bad reputation and I've had a couple of my own blow up. However my current one has over 320 hours on it in less than three years since new. M1 15w40 or 0W-40 since birth, up until last week when I did an oil change and used 15w40 I had on the shelf leftover from my diesel Kubota oil change.
I personally think these engines have two issues going against them. The first would be what most of them are install on, which is your average riding mower, 40-ish inch deck, with the engine sitting under the hood without proper baffling for cooling air to the top of the engine where the fan is. Newer riders usually have a plastic duct that routes the air directly to the top of the engine but older ones, like my old LT1000, just sucked in whatever hot air was under the hood and they just sit under there and bake. I havent used the hood on my rider in years and even after mowing more than an acre I can put my hand on the oil filter without too much discomfort. When I used the hood, in 10-15 minutes you werent touching anything under there without pain and the amount of heat billowing up as I drove it around was unreal.
Second would be, I would be willing to bet most people just use a run of the mill 5w30, synthetic or not, when these engines really need something better to withstand the heat, like a 0w/5w-40, 15w40, or 15w-50 oil.
I personally think these engines have two issues going against them. The first would be what most of them are install on, which is your average riding mower, 40-ish inch deck, with the engine sitting under the hood without proper baffling for cooling air to the top of the engine where the fan is. Newer riders usually have a plastic duct that routes the air directly to the top of the engine but older ones, like my old LT1000, just sucked in whatever hot air was under the hood and they just sit under there and bake. I havent used the hood on my rider in years and even after mowing more than an acre I can put my hand on the oil filter without too much discomfort. When I used the hood, in 10-15 minutes you werent touching anything under there without pain and the amount of heat billowing up as I drove it around was unreal.
Second would be, I would be willing to bet most people just use a run of the mill 5w30, synthetic or not, when these engines really need something better to withstand the heat, like a 0w/5w-40, 15w40, or 15w-50 oil.
ls1mike
$50 Site Donor 2025
What about the INTEK compression release on the cam? I just came into a free one. I believe it low hours as it runs excellent. I will keep it they are easy to work on and parts are cheap.
He would be correct with only 3 engines. Kohler Courage Single Cylinders, briggs intek, and tecumseh OHV vertical ( I forgot the model)
Kohler Courage: The balance unit explodes for no reason. Its not a lack of maint, its a defective casting / metalurgy. Also quite a few will get a cracked block where the cylinder meets the crankcase. Yes the loose bolts can cause this, but the real problem is just a poor design. I have not seen many cam failures, but because they are plastic, they will fail given enough time.
Briggs Intek: Honestly a good engine. A large number of these have defective camshafts. Also the headgaskets can fail, but once upgraded to the latest cam should be ok. Im not sure I can beleive the head gaskets have any type of design problem, I think people over heat them, warp the head, and then have repeat failures. Also the valve seat and valve guide issues, why do you think that happens? Most likely overheating.
Tecumseh: I forgot what models but they had some verticle crankshaft ohv engines in their white outdoors and yard machines units that has an internal issue with the compression release failing. The starters cannot and will not overcome this. Also the carburetor throttle shafts loosen up in as little as 200 hrs and wipe out the rings making them oil burning monsters. You can use a strong electric motor and belt and start them off of the crankshaft as long as they do not have electric PTO.
Kohler Courage: The balance unit explodes for no reason. Its not a lack of maint, its a defective casting / metalurgy. Also quite a few will get a cracked block where the cylinder meets the crankcase. Yes the loose bolts can cause this, but the real problem is just a poor design. I have not seen many cam failures, but because they are plastic, they will fail given enough time.
Briggs Intek: Honestly a good engine. A large number of these have defective camshafts. Also the headgaskets can fail, but once upgraded to the latest cam should be ok. Im not sure I can beleive the head gaskets have any type of design problem, I think people over heat them, warp the head, and then have repeat failures. Also the valve seat and valve guide issues, why do you think that happens? Most likely overheating.
Tecumseh: I forgot what models but they had some verticle crankshaft ohv engines in their white outdoors and yard machines units that has an internal issue with the compression release failing. The starters cannot and will not overcome this. Also the carburetor throttle shafts loosen up in as little as 200 hrs and wipe out the rings making them oil burning monsters. You can use a strong electric motor and belt and start them off of the crankshaft as long as they do not have electric PTO.
That is the big issue, and a gamble when it comes apart. Some times no damage happens other times it can ruin the engine beyond reasonable repair. I find it funny when they break and everyone just fixes it by putting the same thing back in, some times they only last a few starts etc etc. I have one that I plan on fixing that problem before it happens. And the day the head gasket goes if I feel ambitious I will fix that issue as well. Sad that a person has to do the designers work and fix their mess ups.
Some one mentioned up graded cams? They all look like the same junk to me. I plan to install an up graded cam and it won't look anything like what comes out of it.
Who says to avoid Intek engines? My present 20 HP B&S twin has > 123 hours and now issues
ls1mike
$50 Site Donor 2025
Tell me more about this upgraded cam. My INTEK is a 4th mower so I don't mind messing with it.
You have issues NOW? Or NO issues????
It is the single cylinder ones that have the issues, not so much the twins.
It will be a special cam I either make or modify. But will not look like the now mess they have.Tell me more about this upgraded cam. My INTEK is a 4th mower so I don't mind messing with it.
4WD
$50 site donor 2025
Ran a Craftsman/B&S 19 HP for 8 years and gave it away running great and zero repairs - it’s still cutting grass …
Love my 17.5 B&S, zero problems. The single cylinders are known for good torque and fuel efficient. Just don't forget the hearing protection...
You tube is full of DIY of the B&S 1 cyl cam compression release failures on 17.5 HP Intek, up to how ever high they go. So hilarious watching them, anyway shows how prevalent the problem is. I don't know how long that particular engine has been made, but I'm thinking if it is older than maybe 12 years old that could be when better materials were used.
There are cases where at 30 hours it goes kapoo, and some can last over 100 hours or more, sometimes right after a new cam was installed after a few starts to goes out, it is a roll of dice with the cams.
The amazon ones have had the lobes slip, as well as the compress release break. Using PM for the flyweight is part of the issue, the other is a small shaft in a plastic bushing allowing movement, and likely fatigue. It is a case of not if it will break but when.
This cam issue is an example of regressive engineering. That is when they take an ok working design and ruin it with a crappy design.
That seems to be the thing in many industries now.
There are cases where at 30 hours it goes kapoo, and some can last over 100 hours or more, sometimes right after a new cam was installed after a few starts to goes out, it is a roll of dice with the cams.
The amazon ones have had the lobes slip, as well as the compress release break. Using PM for the flyweight is part of the issue, the other is a small shaft in a plastic bushing allowing movement, and likely fatigue. It is a case of not if it will break but when.
This cam issue is an example of regressive engineering. That is when they take an ok working design and ruin it with a crappy design.
That seems to be the thing in many industries now.
