How to lower Honda outboard idle speed?

Discussion in 'Boating and Boat Rigging' started by kroppe, May 19, 2003.


  1. Does anyone know how to do this? Last night I checked my trolling speed at the lowest throttle possible; it is 2.9 - 3.0mph according to the GPS. I think I need to get down to about 1.5mph as a minimum speed for salmon trolling. BTW the motor is a 1997 Honda 90hp 4 stroke outboard.

    My options are trolling bags or lower the idle speed. If I can figure out how to lower the idle speed it would be a free solution. Bags are OK but would like not to have the stuff hanging off the sides of the boat. Thanks for any tips.
     

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  2. kroppe, your motor will idle lower after break in. Put some hours on it and have the dealer adjust idle after break in and lube change. If your idle is at the motor recommended level already, you will need something to slow you down.

    Trolling plates, bags, buckets, kicker motor are some options.
     

  3. ?If its a 97 it should be broken in. Were you in the river? If you were in the river you will go almost 3 mph down stream. That a pretty fast idle. But you could have your prop re pitched.
     
  4. 3 mph at 600 rpm????? Are you sure?
     
  5. mine goes that fast, with my kicker downstream in trenton. but up stream it barely moves
     
  6. ESOX

    Staff Member Super Mod Mods

    Just trim it way up so the prop isnt pushing efficiently. That'll slow you down. Just make sure you keep the water intake submerged.
     
  7. My bad, I assumed kroppe's rig was new from the pix. Maybe even try a smaller or less efficient pitch prop, just watch your high rpms at full throttle though.
     
  8. Kroppe,

    I have a 2000 Merc 75 hp 4 stroke and it runs about 800 rpm, it runs about 2 mph by the gps, I asked my dealer to slow down the idle so i would be able to troll slower. They checked it out and said it was set to the book. I check the repair manual and idle speed is 800 according to Mercury, i believe it has something to do with it being a 4 stroke. Check the specs on the motor before you lower the idle speed, it might cause damage if you slow it down.
     
  9. ESOX

    Staff Member Super Mod Mods

    BTW Kroppe, Thats one fine looking rig you have there!:cool:
     
  10. All the 4 strokes i 've been in seem to run slower in idle mode. My friend has a 50 hp honda and it actually goes backwards in the river. My cousin has a 115 yamaha and it goes slow enough for me to handline. Just seems that is way too fast
     
  11. Thanks for all the help. Here is a comparison I did, still has some holes in it. All motors are 4 strokes

    [​IMG]

    I need to re-check the idle speed for the Honda, I can't remember what it was last night. The service department at Krupa's in Jackson told me it was 800. Seems high.

    Couldn't find any info on Mercury, seems the power head is made by Yamaha but no Yammie 90hp. Looks like trolling bags are the way to go.

    Thanks Esox. It's been a good rig so far.
     
  12. Do you have the info on merc power heads made by yamaha? Motor news is getting interesting.
    Yamaha, owned by bombadier
    Johnson/Evinrude, purchased and owned by bombadier
    merc, Yamie heads???????????
    Sounds like someone really owns the market.
     
  13. Here's some data from the water tonight. The first shot is the motor idling in neutral. GPS says 0.5mph but we were just bobbing around. Idle speed is about 750rpm or so.
    [​IMG]

    The second shot is the engine idling in gear. Idle speed in gear is about 675-700rpm, with boat speed about 3mph.
    [​IMG]


    So it seems like the idle speed is in the ballpark; don't think I want to mess with it. Looks like bags are the way to go, lacking a gas kicker.

    Does anyone out there use trolling bags for salmon fishing? Likes/dislikes, any tips for success?
     
  14. Kroppe,

    You mentioned that your top speed was about 40 mph at
    5840 rpm, you might want to look at what your rpm should be
    at wot.
    I have a 4 stroke Merc and max rpm is 5,000 to 6,000. If you
    want to sacrifice a little on the top end, you could try a different
    prop, if you go with a smaller pitch it will slow you down for
    trolling, just keep and eye on the rpm so you don't exceed max.

    If you decide to go with the bags for trolling, one of the best
    methods would be one bag on each side, tied close to the bow,
    only problem with this is they have a tendency to go under the
    boat, you could add a second line to prevent this.
     
  15. Like STEINFISHSKI said, you could use a different prop but you gotta watch that you don't over-rev your engine. The factory prop you have now is probably one that makes it that you can't over-rev your engine.

    trolling plate would be your option.
     

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