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Is 12hp plenty of power for a 42" Deck?


B.Ikard

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Looks like I am going to have to go thru my 7012's engine. I knew it was "tired" when I bought the tractor,but am trying to decide whether to make a 7016 out of it for a tad more $$ than building it back a 12. Was mowing leaves last weekend on some steep hills and the hydro pump was giving that 12hp all it wanted. Will the 12 pull a 42" deck well, or would the extra 4 HP be appreciated? Some local folks say the 12 is all I will ever need, others say build a 16... when I worked at a Simplicity dealer we never sold 12's,only 7116's and 7117's so I never have really used one. I am estimating spending $400 or so on a 12 rebuild, and don't want to be kicking myself for not spending $150 or so more and having a 16 (341 block,head,and carb). I plan on keeping this tractor and probably restoring it as well,but I am a working stiff and don't spend money that won't be worth it. Any info,experiences, or advice would be appreciated Ike
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12HP is plenty with a gear-drive tractor -- 12HP is the minimum for a hydro tractor -- the 4 extra HP is certainly noticeable, but IMO is overkill for a 42" deck....
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I have a 7010-6 with a 42" deck and it works just fine. I will admit being on fairly flat land but it does handle tall grass. It works, make no bones, but does the job.
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maxtorman1234
I was using a K341 in my 416H with the 42" deck, and the same deck on my 12HP 410S. Even with the hydro, the 16HP made a huge difference through the long grass. The 12HP was having a hard time, but the 16 went right through it. I find there is a huge difference between them, and I prefer the 16.
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Again, I am the oddball. My 716H actually has a l0Hp engine on it and I have been mowing with a 48 inch mower on it for the last two years. 10 Hp, 48 inch mower, and hydro. I'd say 12 Hp should be plenty for a 42 inch deck.
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quote:
Originally posted by Kent
12HP is plenty with a gear-drive tractor -- 12HP is the minimum for a hydro tractor -- the 4 extra HP is certainly noticeable, but IMO is overkill for a 42" deck....
I have a 3410H sitting here waiting for me to decide on rebuilding the engine or parting it out. Is this a rule of thumb about the 12hp and a 42" deck? The comment caught my eye when I read it.
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Depends I guess on what and where you are mowing. Both Rod and I have 10HP machines. I too have had a 48" deck on mine and it worked OK. Keep in mind that an 8HP Brodmoor for years handled a 36" mower and did an OK job. So I guess it depends on the lay of the land and how long you let your grass grow.
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I have a HB-212 with 48" deck and it has plenty of power to do everything I want it to do. I did some brush hogging with it this summer and it did fine. I mulched a 2" thick blanket of Oak and Maple leaves Sunday and no problem.
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Firefox, as far as I can tell (from memory, without looking it up) 3300/3400 series were the only tractors offered with a 10HP and a hydro, and they didn't come with 48" decks, only 42".... IMO, it is underpowered with a 10 HP based on 2 things: 1. A hydro typically "robs" about 2HP to operate the pump -- leaving only 8HP to run the mower deck and pull the tractor... 2. My personal experience: (a) running a strong 10HP in my now HB-216 hybrid with a Sunstrand hydro. I ran it that way most of one summer, and it would stay on governor most of the time the deck was engaged -- telling me it was working very hard. (b) same tractor with a 16HP and 48" deck, on the same lawn, only goes on governor when climbing a hill or when using the vac... (c) my 3112V with variable speed, 12HP, and 48" deck spends more time on governor when mowing than the HB-216 does now, but has noticeably much more power than the 10HP hydro combination On a smaller, flat lawn, a 10HP hydro would probably give acceptable service -- but the 12 HP is a much better match....
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Actually it also depends on how much you cut. 1/2 acre just go slow, I cut 5+ acres. Too much to cut twice a week in peak growing seasons like this year. I prefer 16-20 hp and a 48" deck.
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The smallest hydro tractor I know of that Simplicity made was the 3310 H, and it was the only one that I'm aware of that had a 10 horse engine. The rest were all 12 horse or larger.....
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Ike, The general idea sames to be that 10hp 12hp 14hp is enough power, but I believe we'd all like to have more power at different time for different jobs. My 914 AC is great to cut grass, but put the pto powered leaf vac on it and you can see a big different in power. I'm thinking of putting a KT17 I have on mine for that reason.Just my opinion like everyone else.
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I have a 7012 with a 42" deck 12 hp.,and it cuts very well. Tim Taylor's more power theory is a nice idea but not needed just for grass cutting.
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Ronald Hribar
Put the 16 in and you will never have to wonder if you should have done it. Unless you are looking to keep it "orginal". I can not see any disadvantage of putting a 16 in.
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I might be inclined to go with the 16, but, my 725 (Mod 19, 7.25 Hp) does just fine with a 42" deck and the pto powered leaf vac doesn't bother it a bit.
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More horsepower never hurts.... My B-10 has a 42 inch deck and I used to cut with very little problem in grass halfway to knees.
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I have a Big Ten and a B-12. The Big Ten has never had any engine work done on it and it proabably has the higher hours as the original owner used it for mowing for 36 years. (for real, and now they miss it!) The 10hp uses oil at about 6 to 10 oz per tank of gas depending on how hard I am working it. Mowing is the hardest on it. The B-12 was "freshed up" by the original owner whom was an old automobile mechanic by profession. It uses no oil and it does handle the mowing chores with more ease than the Big Ten. Both are gear tractors, obviously, but I would not be afraid to put a 48" deck on either one if it would fit. These old briggs engines were designed to deliver maximum torque through the RPM range. If you want to restore, stay with the twelve. If you have the money and want to work the tractor without regard to restoration then spend the money and make it a 16. You won't have to wish later you had or wonder if it would make a difference.
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Thanks Guys for all your input.... Been educating myself on these engines and is amazing what is out there. These engines have caught on with the pulling crowd and a lot of "high performance" tricks and products are out there. Still working on a plan but nothing has been real straight foward. The 16 hp Kohlers are very pricey as that is what the pullers want. Right now what I am pondering is a 14hp block and crankshaft to make my 12 a 14..... Researching the Magnum series Kohlers as far as drop in swaps, and the biggest thing I have found is the Simplicity drive coupling attaches to the Kohler flywheel by 4 bolts (used for a puller). The Magnum series only has 3 tapped holes for a puller:(! None the less it might be worth considering having a machine shop either alter the coupling or drill/tap flywheel. Thanks again, Ike
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I was curious about that Magnum in early tractors as well. I wonder if an adaptor could be fashioned with the three holes for the flywheel and the two required for the drive coupler?
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[quote]Originally posted by maxtorman1234
Can't you just change the adaptor from the flywheel if thats the problem? That's the problem...I do not know of a source to get a drive coupling flange that will fit the Magnum engine. The older K series compatible flange is available thru Kohler @$80.00 ea but this design coupling is not listed in the Magnum parts breakdown. The problem is going from a 4 bolt flange on the K flywheel to a 3 bolt flange on the magnum flywheel. I suppose holes could be drilled in the existing flange but it might be too thin afterwards. From the online parts breakdown http://www.smallenginepartswarehouse.com/parts.asp things might line up with 2 bolts securing the flange. Remember this flange/coupling is the link for 100% of power transfer that rotates @ 3600 rpms. The other alternative would be a custom fabrication-could be fairly pricey as I do not have access to a mill or lathe. Ike
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The more horsepower the better.The 16 will be 30% less strained than a 12 doing the same job.For pulling you may want torque but for grass cutting I like RPM.I'm putting a 25 Briggs in my 19 hp Murray to enable me to cut the grass at a faster ground speed.
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If it was me I think I would go with the bigger motor...That way if you ever decide you need a bigger deck you will have Hp needed to run it plus it is better to have more than enough than not enough...Just my opinion..
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I have a 7112. 42 inch deck. Hydro. 12 HP Kohler. Right now I'm using it to vacuum leaves and the tractor is handling the cutting and vacuuming with no problems. If I were upgrading, and I had the money, I'd go a little bigger with the motor, to give it more guts. But if you're just going to cut grass (normal length) 12 HP is more than enough. Larry
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