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MORE POWER!!! - Anyone ever "hot rod" thier mower?

Discussion in 'Starting a Lawn Care Business' started by elamey, May 2, 2006.

  1. elamey

    elamey LawnSite Member
    Messages: 75

    I'm opening the door for some 3rd degree flame...but here goes.

    Anyone "hot rod" thier mower? I've got a 2005 60" lazer/z with a 27hp Kohler air cooled. This spring it seems like i'm low on power, the grass is heavy and wet and all that, but it's bogging down. I am mulching and the blades are SHARP, changed every few lawns. Air filter has approx 10 hours on it, Motor is turning at normal speed and the belts seem to be good tension (not too tight, but not loose). It's probably running normally...I probably just need to have a couple of beers and forget about it.

    Anyone ever "hot rod" this motor to get more out of it?

    Moderator: If this is too stupid of a thread feel free to delete it, my little feelings won't be hurt.:weightlifter:

    PS - I wonder if the mule drive could be mated up to a Harley engine. Say 100hp/100tq....
  2. GreenUtah

    GreenUtah LawnSite Senior Member
    from SLC, UT
    Messages: 866

    you know, there is a mower racing association with probably all kinds of tips on ruining your work mower...I did notice that you didn't mention spark plugs or the oil weight, but I'll assume you're taking care of those issues.

    On the side note, I did see a monster garage a few years ago where they converted a mustang into a mower with reels that dropped out of the doors while driving...can't recall if it actually cut anything off......
  3. JJLandscapes

    JJLandscapes LawnSite Senior Member
    Messages: 682

    haha yea i remember seeing that and it had to cut grass in order to break some record

    anyway my friend has a site that will take chainsaws and nearly double the horsepower with a little work im pretty sure anything with an engine can be modified somehow for more power
  4. mike lane lawn care

    mike lane lawn care LawnSite Bronze Member
    Messages: 1,707

    cold air intake
    flowmaster exaust
  5. MuleCutter

    MuleCutter LawnSite Member
    Messages: 212

    the conditions you are cutting in combined with the size mower you are using is very common, especially if the grass is wet and heavy. there is a way you can up the engine RPMs by pulling back on the governor. i wouldnt suggest this though because most engines are recommended to run about 3600 rpms... this adjustment can cause premature engine wear.
    i work for a dealership that sells Exmark. i see and hear this same complaint all the time. what i suggest is keep doing what you are doing as far as maintenance goes and when cutting... just slow your ground speed down a little bit but keep your throttle at full speed. if you still are not satisfied... exmark came out with the new TRITON deck which is a little bit deeper and gets more air flow in the deck... and trust me... it does NOT....and i mean NOT!!! bog down..... it has flow control baffles that are adjustable for mulch and discharge..... i jsut bought a 19 hp 46 inch cut with the new deck. mine cut the grass easier than a 27 hp 52 inch cut that i used because of the new deck.

    hope this helped...

    p.s. - plain and simple... if you want more power... the answer is YES you can get it by doing what i said.
  6. Killswitch

    Killswitch LawnSite Senior Member
    Messages: 438

    Im quite sure theres a lot more horsepower in these motors. Id start with porting and polishing the heads. Of course all these motors are governed.

    Theres probably some horsepower gains with an illegal flowable exhaust...with backpressures but not what the epa prescribes.

    Shorten the stroke and increase the cylinder bore....

    Play with the pulley sizes and increase blade speed.

    Im sure theres a lot of possibilites....the manufacturers are bound by rules that the fabricator isnt.
  7. topsites

    topsites LawnSite Fanatic
    Messages: 21,653

    Why not just change the oil to either a full synthetic or a synthetic racing blend and run BP 93 octane premium for starters, and if you really want to get stupid like me you find some racing fuel and add about a pint to a quart of Sunoco 110 octane leaded to every 5 gallons of premium and not only will nobody steal your fuel but you will have the wonder mower.

    By the way, if yours is string start (well mine is), it will start with about 1/4 string pull, left-handed at half or less your full strength.
    My weedeater starts when it's warm barely pulling about 4-6 inches of string out lol

    Do NOT let fuel get into the exhaust after it's been running (such as stupidly turning over the engine with ignition off or some such thing) or it will shoot out a flame which is actually a cool trick if you're just goofing off.

    I am so red :laugh:

    here's a pic of 93 premium + sunoco 110, it is clear light blue:
  8. GreenUtah

    GreenUtah LawnSite Senior Member
    from SLC, UT
    Messages: 866

    ok, so on the part about bypassing the rpm governor...not only is this there for your engine, but it's also the max rpm for your hydro pumps..hmm..600 a piece to blow them up..your decision. Oversizing pulleys on the deck to get higher blade tip speed? the ANSI limits are there for a reason and the blades are built within those tolerances...blade warp or even shattering are distinct possibilities for a significant speed increase..ever see a cd player that has been pushed past 52X? it can still read the info at higher speeds, but the discs begin to warp and even shatter apart becasue the balancing is only so good. Want to take a guess at the perfect balancing of your blades? lol..just keep the machine well maintained, cut a little higher when it's long and wet, or cut twice and charge the customer for it and you'll be fine.
  9. Richard Martin

    Richard Martin LawnSite Fanatic
    Messages: 14,699

    Actually, increasing the engine RPM has nothing to do with the governor. On OPE the governor's sole purpose is to attempt the increase RPM as RPM drops when the engine encounters a load. The max engine RPM is controlled by a simple throttle stop that controls how far the throttle cable can move the throttle plate in the carb or TB (if EFI).

    I have heard stories of people running Dixie Choppers in excess of 4,000 RPM but it's not something I'd do. You are right, you will wear out a engine faster when it is run at higher RPM.

    Dixie Choppers also come from the factory with BTS well in excess of 19,000 FPM. Closer to 21,000 FPM is the norm.
  10. JJLandscapes

    JJLandscapes LawnSite Senior Member
    Messages: 682


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