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717 and a 728


rsnik

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I now have a 717 and a 728. The 728 is pristine with an excellent deck. The carb looks obviously recently rebuilt. The fellow I bought it from just got it from the orginal owner, was thrilled, had it at wide open throttle while adjusting the carb and the rod came through the side of the engine case. The 717 has a plow, no deck. I got 75 lbs of compression turning the engine over cold when I got it. Added some clean gas with some Marvel Mystery oil in the gas, ran it for a while and got 89 lb compression. It is finicky to start. It does start though and produces good power. I bladed some landscaping with no problem. The carb is worn with lots of slop in the throttle plate bushings. It leaks oil to the point of messy and annoying but not enough to risk running too low too fast. The 717 is a 7 HP, correct? and the 728 is 8 HP? The engines look identical, what gives the extra horse, the carb? larger displacement? Can I use the new carb on the 8hp on the 7hp engine? I think I should buy one of those rebuild kits and replace the piston, rings and gaskets in 7 hp before swapping it with the 8hp on the 728 (hate to cannibalize the 717 but the 728 is a nicer tractor. I would much rather find another 8hp. A member has one out of a 5008 series Broadmoor, does it have the correct crankshaft length and pulleys etc to make for a direct replacement? I welcome any comments and observations you have. The 717 starter/generator starts the engine and charges the battery fine. It does not make worn bearing noises. But it gets quite hot to the touch after 20 minutes of using the tractor. Is that normal or a signal to tear it down before something craps out? A lot to ask, I know, but this is my new life as the novice convert to Simple tractors. Incidentally, I look at how the deck is attached on the 728 and it is awe inspiring, such a brilliant, simple, effective design. I can remove the deck and attach the plow in 15 minutes. Best, rsnik
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Yes if the 717 has the correct motor it would be a 7hp and the 728 would be a 8hp..The 7hp is a 17cu. in. and the 8hp is a 19cu.in.If you read the numbers on the motor flywheel cover there is a model,type,and code numbers..The first 2 numbers of the model is the displacement..The first 2 numbers of the code is the year the motor was made.. If the motor doesn't smoke or sound bad I would just put gaskets ect. in it.. I think the 5008 would have the same shaft size but I am not 100% sure..I belive the pulleys are probably diferent though and you would have to swap them out.. As for the starter genorator..I don't know and mine does the same so I am looking forward to seeing a answer to that one myself..
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Thanks mowerman, the numbers on the 728 would indicate a 19 ci engine built in 1971. The new carb on the 8hp is identical in appearance to the worn out carb on the 7hp. Will the carbs switch out without issues? I think tomorrow I am going to throw the deck from the 728 on the 717 and see how it mows (it's a beaut of a deck.) I was going to swap engines but you know how that sometimes goes. Might be fun to go play with it before the millions of bits all over the garage thing starts.
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Yes the carbs. are the same..You should be able to swap most everything from motor to motor as far as external parts such as the sheet metal and coils ect..
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