The pontoon boat in the linked test is much lighter than the Mac26. Just consider heavier means lower MPG.

Divecoz, I have not posted in a long time. Back in 1999-2000 I tested 9 props on my Mac26X with a Suzuki DF50. I found that the 4 bladed 9 pitch with large surface area was as fast as the 4 bladed 10 pitch. I finally settled on a 3 bladed large surface area 9 pitch stainless prop, but I had it cuppe...

I used a Piranha Propellers foil on my Suzuki DF50. It helped keep the bow down when motoring at high speed. It also made the boat lean when turning at speed. I think the foils are tools that can be used with good results when operated by someone that understands them. The motor angle (trim) with po...

I drilled and tapped a hold for the ballast valve stem in a 316 stainless steel rod about 4 inches long. Thread that on the valve and the handle breaking is no longer a problem. .. There might be a stainless hardware item that has the correct threaded hole already. IIRC the 1999 Mac26X ballast valve...

DirectHits cause the spark energy to more efficiently get to the spark plug, so there is a bigger spark. .. DirectHits cause the spark to happen faster, a short duration very intense spark. The fuel ignites quicker and the engine has less tendency to pre-ignition allowing the engine computer to adva...

albion, The 12 1/2 by 8 pitch sounds OK, as long as the diameter of the prop fits without interference. Also, as the diameter of the prop gets bigger there is more chance of sucking air from the surface, if it does it is called ventilating. To stop ventilating lower your motor or slightly cup the pr...

Terry, I view the prop materials available as four types. 1.) SS Stainless Steel 2.) Aluminum regular soft casting 3.) Solas pressure cast aluminum hard casting 4.) composite usually nylon with fiberglass inside .. The stiffer and stronger the prop material the thinner the prop can be and that is go...

I tested 9 props on my Suzuki DF50. The Suzuki engine turns a few more rpm and has a little taller gear ratio than the Honda, but both turn the prop at the same prop rpm. .. So, if this board keeps old messages search able, do a search for Suzuki DF50 prop test or prop pitch and you will find lots o...

Same RPM from on two very different size outboards will provide very different boat speed. The larger motor moves the boat faster at the same RPM. To compare fuel consumption compare at the same boat speeds.
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If you tow with a vehicle not really designed for towing, pay really close attention to the condition of your trailer. .. Do not assume the trailer brakes will work, make sure your tow vehicle brakes are in good enough shape to stop itself and the trailer without depending on the trailer brakes. .. ...

Did you test for rust in the enclosed trailer structural parts? The center beam on my Mac26X trailer is a box frame. I have heard of box frame parts that still look good on the outside, failing catastrophically from rusting on the inside.

I like the idea of a four blade prop and lots of torque and a long shaft, those are all things that Honda says it's BF20 delivers. .. http://www.honda-marine.com/modelDetail.aspx?modelGroup=BF20 .. Maybe 20Hp won't make you go faster, but what if you want to go very quietly. I think a four bladed 20...

Running great up to 3000 RPMs then missing is exactly how the rev limiter works. .. When the RPMs in overheat condition reach 3000, the engine computer decides you no longer need a spark or fuel. The engine begins to slow down, the computer notices less than 3000 RPM, so gives back spark and fuel, t...

If you are sucking air at the top of the prop there are two ways to fix it, more cupping of the prop or lower the motor mount on the boat.

The Tohatsu / Nissan 18hp is light for its power, but heavier than it used to be http://www.tohatsu.com/outboards/18_4st_spec.html .. The Honda 20hp is light for its weight and comes in a sailpower version with high thrust 4 blade prop: http://www.honda-marine.com/modelDetail.aspx?modelGroup=BF20 .....