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? Kaw V-twin RPM

Discussion in 'Lawn Mowing' started by jsaunders, Aug 29, 2002.

  1. jsaunders

    jsaunders LawnSite Bronze Member
    Posts: 1,781

    I have two Ferris DD w/b's. 1 has a 15 and the other has a 17 hp motor. I just added an electric hour meter/ tach to both. The 15 will rev at a little over 3500 rpm. The 17 with the blades turning will only rev tops of 3420 rpm. Its funny I had always thought that the 15 cut better then the 17- it has some extra revs. what are your machine turning for RPM and how can I adjust mine? The dealer tried to quickly adjust the carb but now it runs ruffer and it has backfired acouple of times. These machines are new this year. Any suggestions or comments are appericiated. Thanks
  2. awm

    awm LawnSite Gold Member
    Posts: 3,354

    dont own one rite now. but talkin to a member with a 27 efi i think. think he said he ran his at 3750. im sure u ll get first hand info here tho.i think efi is the rite term. anyway i assumed it was the liquid cooled.
  3. Dennis E.

    Dennis E. LawnSite Senior Member
    Posts: 349

    Thats what i have on my WB. RPM's are 3300-3450 normally.(Where I run it anyway)
    As for changing the RPM's I'd leave it alone. Its set at the factory.
    I've got the 25 Kaw. on my ZTR and the "suggested" running is around 3300.(From the mechanic at the dealer)
  4. TLS

    TLS LawnSite Fanatic
    Posts: 7,940

    Are these FREE LOAD rpm's or are they with the blades engaged?

    FREE LOAD they should be (at least) 3600. Many people have free load set as high as 3800 rpm. I'd stay under 3700 for now. Depending on how many hours you've been running this low, you may have developed a bore ridge. Cranking it way up real quick could cause ring problems.

    This is a perfect reason why ALL mowers should have an Hour Meter, and ALL mowers should have a Tiny Tach.

    Crank 'em up!

    On Edit: Dennis, You are also WAY too low on RPM's. They are NOT set at the factory as many believe. ALL these engines NEED 3600 RPM's to properly cool and be in their power band. It says it in EVERY owners manual. HI-IDLE .....3600 RPM.
  5. jsaunders

    jsaunders LawnSite Bronze Member
    Posts: 1,781

    Thankyou TLS! How did you turn up the RPM's? I added the tachs after finishing the days route.- I'm not sure of the loaded rpm on the 15 hp- I don't use it to much but the 17 hp like I said top rpm's under load were 3420 - usually were a constant 3380-90 throught the other day. The carb does need some work the engine is noy smooth at all. It's a shame I've had snapper mowers for years with the B+S engines and were no problems. I have to tell myself that it isn't the Ferris mower it is just the Kaw engine giving me problems- BUT that does little when I'm PISSED because the mower won't rev and back fires when I shut it off (in an enclosed trailer) puts a little ring in my ears. Thanks
  6. Premo Services

    Premo Services LawnSite Bronze Member
    Posts: 1,516

    Behind the air filter is a plate where the throttle cable comes in with 4 screws, take 3 out and one just gets loosened to slide the plate up or down to raise the rpms.
    My 17 kaw was the same way when new. Could'nt figure why the cut was louzy. Got a hour meter and tach, they were low. I raised the rpms to 3600, and the cut was the way I expected it to be.
  7. TLS

    TLS LawnSite Fanatic
    Posts: 7,940

    These 15 and 17hp units are twin cylinders. They can run smoother at higher rpm's than a one holer. I'd put the RPM's at 3700 free load. This way the mower will never mow with rpm's under 3600. You can usually expect a 50 rpm difference with blades engaged.

    Premo is 100% correct with the rpm adjustment of Kawi's.
  8. Some Kawi engines may only top out at 3500rpm's with the adj plate, you must inturn bend the govener to throttle butterfly valve linkage to aquire a higher RPM.

    To find this look for the throttle butterfly, then back up to about the middle of the linkage then bend it with needle nose pliers.

    If you engine is running lower than 3450 it will run hot when used under a load.
  9. 65hoss

    65hoss LawnSite Fanatic
    Posts: 6,360

    I had to do some tweeking on my kawi motors. I turned the w/b back up today. Cable stretch this time. The lazer needs it and will get it tomorrow.

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