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deere 65 engine options?

968 Views 6 Replies 4 Participants Last post by  Tractor-Holic
Hi guys. I purchased a deere 65 riding mower a couple of weeks ago and the 5 hp tecumseh engine on it is showing signs of it's age. I'm thinking of changing the motor on it but i dont want to put a big one in. Can i put say a 6.75 hp brigg in from a lawn mower? Seems to me it would be enough for my son to ride it. I dont want a batterie and starter set up because it's a pain in the neck to buy a 70$ batterie so i sort of tossed the whole 8 hp and up brigg idea. What do you guys think?:thanku:
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He's corrcet,we discussed this in another thread on the Murray forum..

I have used push mower engines on riders and home brews by using a cast iron pulley ,heavy enough to offset the loss of the blade's "flywheel effect"..most push mower engines used a 7/8" bore crank PTO,so you will either have to buy a cast iron pulley with a 7/8" bore,or it might be possible to get away with using an original pulley if it was 1" bore with a bushing ,as long as its heavy enough to let the engine start and idle normally..

I have cheated and used the original blade adapter to mount a pulley,but drilling two holes in the pulley to match the two that held the blade to the adapter originally..its critical to center it good ,and one disadvantage to this method is the pulley is way at the bottom of the crank,so it'll be nessasary to used spacers between the engine and its mount to jack it up,and align the pulleys so the belt will stay on..

If you use a 3.5 HP Briggs vertical shaft push mower,a cast iron flywheel off a similar horizontal shaft engine might fit in place of the aluminum one and work..
I once had a mini-bike with a 3.5 Briggs and I tried putting a push mower aluminum flywheel on it--it kicked back like a mule when you went to start it,and it was diffucult to get started and to idle below 1500 rpms--but once you got it going,it revved up quicker than a top fuel dragster!..thing felt like a 10 HP..for about 15 minutes,until the connecting rod turned into nuggets!..:D
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I'd not be fearful of using a push mower engine,but I would also take the 6.75 HP ratings with a bit of skeptasism,because I have a Sears push mower with a 6+ HP rating on the sticker,but in reality,its less powerful than many of my older 3.5HP ones in deep grass!..its all about "numbers" and not actual performance..but if its just going to pull your son around one would work fine,many older "sit down" mowers had 3.5 or 5 HP engines and did OK..a smaller motor will burn less fuel too,an important consideration in todays for push mowers will be more plentiful too,at our dump on any given Saturday,there is usually at least 3 of them in the metal piles,often noting more "wrong" with them than a busted pull cord,or a wheel rotted off the deck,etc..
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