mud motor kit or plans

Discussion in 'Mud Motors' started by nwmohunter86, Jan 12, 2011.

  1. nwmohunter86

    nwmohunter86 Senior Refuge Member

    Messages:
    159
    Joined:
    Dec 10, 2009
    Location:
    St. Joseph, Missouri
    Looking to build a mud motor. Looking at using the harbor freight 11 or 13 hp motor. going to use it on 14' jon. If anyone has plans that would be great. Im kinda stuck on how to build the shaft? anyone built one? or can you just buy the shaft?
     
  2. Doghandler

    Doghandler Refuge Member

    Messages:
    38
    Joined:
    Dec 15, 2009
    Location:
    Ohio
    Mad Mud Motors... Their plans show the detailed build of smaller engines, but they also include what to change for bigger ones. Look em up on ebay... about $30 for the plans. I bought them and they look good. Been too busy to start a build though. Hopefully in the spring
     
  3. Rolen_Zen

    Rolen_Zen Refuge Member

    Messages:
    58
    Joined:
    Sep 9, 2008
    Location:
    Iowa
    A friend and I used the Mad Mud Motor plans from ebay to build 2 longtails. We used the 13HP Greyhound motor from Harbor Freight and they have worked well for 2 years. Make sure you find the 20% off coupon that Harbor Freight puts in Outdoor magazines and flyers. We used the savings to purchase a 3 year, unconditional replacement warranty.
    The plans from ebay are for a 6HP build, so we used them as a guideline for building our motors. Some things will need to be tweaked for the larger motor. Instead of building the transom mount, we were able to use salvaged outboard mounts, one from a 6HP Johnson, and the other from a 25HP Mercury.
    The hardware we couldn't find locally was purchased online from McMaster-Carr and driveshaftparts.com, and the steel was purchased at a local supplier. Each motor cost us about $700 to build, not counting our labor.
     
  4. nwmohunter86

    nwmohunter86 Senior Refuge Member

    Messages:
    159
    Joined:
    Dec 10, 2009
    Location:
    St. Joseph, Missouri
    How was the shaft put together? was it easy to do?
     
  5. Rolen_Zen

    Rolen_Zen Refuge Member

    Messages:
    58
    Joined:
    Sep 9, 2008
    Location:
    Iowa
    I'm not sure what part of the shaft you're referring to, but it all went together just fine. The shaft we used is 3/4" cold rolled steel as called for in the plans. We cut it to size and had the machine shop cut the threads for the prop.
    The shaft tube is fitted with 3 bushings, top, center, and bottom. The center bushing was pushed in with a broom handle.
    The top end got one seal and the bottom end got 2 seals with the first one put in backwards and the second one put in the correct way. This makes it more watertight. The drive shaft needs to be greased well before sliding into the tube.
    We connected the drive shaft to the engine shaft using a u-joint with the appropriately size yokes for each side. I believe the engine drive shaft is 1" or 1.25" and the prop shaft is 3/4". We also added some collars on the engine side between the u-joint and the engine as the yoke wanted to slip towards the engine side despite have 2 set screws locked down.
    The part you need to be most careful with is aligning the shaft tube with the engine drive shaft and setting the downward angle of the shaft tube. I believe the plans call for a 15 degree angle, but we tweaked that a little for our boats.
     
  6. extra mud

    extra mud Elite Refuge Member

    Messages:
    4,343
    Joined:
    Jul 7, 2003
    Location:
    Sussex , Wisconsin
    4340
    3/4" dia 72" long
    1/8 kwy on motor end
    3/4"-10 thread on prop end

    Angle is 15 degrees
     
  7. Ringbill

    Ringbill Elite Refuge Member Flyway Manager

    Messages:
    4,164
    Joined:
    Jul 8, 2000
    Location:
    Squaw Lake,MN USA
    I'm not a welder or fabricator, so I had my friend help assemble all the parts that came in a kit, with the stainless prop, from the Bog Hog mud motor company. It worked out pretty well and I downsized the motor to a Honda 6hp and 'shrunk' the prop to fit it

    Ringbill
     

Share This Page