Engine swap on older mowers?

Discussion in 'Lawn Mowing' started by BadRancher, Jan 22, 2011.

  1. BadRancher

    BadRancher LawnSite Fanatic
    Posts: 5,887

    Have any of you guys swapped engines on older mowers? I have an older bobcat that I'm thinking of bringing in on more cutting. Currently it has a 14hp single cylinder. It still runs pretty good, but bogs to easy in thicker stuff. I would like to upgrade to V-twin 15 or 17hp. Have any of you guys done this or tried to do this? Does the rest of the mower hold up to the power increase?
     
  2. knox gsl

    knox gsl LawnSite Platinum Member
    Posts: 4,851

    I up graded my TT last year when the engine died from a 20hp to a 23hp kohler. Your best bet would be to contact an engine supplier; http://www.smallenginewarehouse.com/, http://www.opeengines.com/, or something similar and give them the spec number off the current engine. If the current engine doesn't have that information then use the serial and model number of the mower. Last case option would be to remove the bottom pulleys and measure the crank, engine bolt patten and carb control linkage. They should be able to get you setup. The least I would do on a repower for a 48" mower is 19HP if you see alot of 14day cuts in bermuda and bahaia grass.
     
  3. BadRancher

    BadRancher LawnSite Fanatic
    Posts: 5,887

    Thanks for the info. I just need to find out if the rest of the mower can hold up to a power increase. Then Find out if there is a motor that will bolt up to it.
     
  4. djagusch

    djagusch LawnSite Platinum Member
    from MN
    Posts: 4,203

    Holding up to pwr ? I don't think I would be worried about it. If it is a belt drive the peerless trans is stilled used today and can handle modern pwr. On a hydro unit I would say the same thing, they also tend to have bypass valves built in. 17 to 19 hp is all a wb needs.
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  5. BINKY1902

    BINKY1902 LawnSite Bronze Member
    from South
    Posts: 1,123

    You just have belts connecting the engine/hydros and engine/pulleys, and your turning the same rpms if it's a 14hp or a 17hp, so it's not gonna hurt the machine. It's not like a car, in which you have components directly taking the power from the engine. Just get an engine with the same bolt pattern for mounting, and the same shaft size and length, so you don't have to even worry about finding another engine pulley to fit. Even if you had an electric blade clutch I don't see that small of an increase in power affecting it.
     
  6. BadRancher

    BadRancher LawnSite Fanatic
    Posts: 5,887

    I didn't know. I thought maybe with the extra power and torque on the drive and blade belt systems or on the pulleys and spindles could cause problems.

    Sounds like the things I really need to worry about are the throttle control on the control area and etc. The way it is set up on this is the throttle is also the choke when you max it out. I assume that on a new motor the choke would be on the motor itself like newer model Kawi's are.
     
  7. Landrus2

    Landrus2 LawnSite Platinum Member
    Posts: 4,811

    Kawasaki 15hp twin cylinder will be fine:drinkup::drinkup::drinkup::drinkup::drinkup:

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  8. djagusch

    djagusch LawnSite Platinum Member
    from MN
    Posts: 4,203

    Your really over thinking this. Buy a pull start engine with the same mounting holes (they give specs on this), same shaft size and type(taper/keyed/ect). Mount it up. Buy some cables (hint if you buy a engine that is the same as a mfg, buy the cables from the mfg dealer). Mount up the throttle/choke and you are done.
    Posted via Mobile Device
     
  9. BadRancher

    BadRancher LawnSite Fanatic
    Posts: 5,887

    Are you saying if Kawi motor get their throttle cables or are you saying get Bobcat cable and etc. I'll probably be getting the motor online.
     
  10. BINKY1902

    BINKY1902 LawnSite Bronze Member
    from South
    Posts: 1,123

    When you buy a motor you can get one designed for remote cable controls, which means you can control your throttle and choke from the machine.
     

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