What is your speed? - Zodiac Futura Mark III (with a 40HP 2 stroke)

[0976claxton]

In the spirit of another thread that I've read on this forum, I was wondering what speed others are getting out of their Zodiac Futura MKIII with a 40HP 2-stroke. I just purchased a used 2002 Tohatsu 40HP 2stroke and I took it out for the first time yesterday. I had a full 6 gallon tank, scuba tank and my anchor all placed within the bow. I had two riders sitting on the pontoons in the middle of the boat (combined people weight of 300lbs), then myself and a marine cycle battery in the back working the tiller. The seas were just a little rough, but my max speed was only 24mph. At this speed I noticed I was completely not trimming correctly (evident by the water coming up and over the transom). I reset the motor at the fourth trim hole out, but I have yet to relaunch at the new setting. I would imagine that I should be getting over 25mph, right?

must say, that 40HP is a bearcat to hold in place due to the torsional force causing the motor to turn the boat to the right. a steering console is sounding pretty good right now.

please post your speed at WOT and your experience with the same set up.

 

[jondavies]

Re: What is your speed? - Zodiac Futura Mark III (with a 40HP 2 stroke)

I have a comparable boat (Avon 4.60M Super Sport) with the same motor and it goes about 23-25 mph with a similar load. I'm interested to hear what others say about squeezing more speed out of this configuration.

To tame the tiller, try tightening the tension on the steering column (look for the 1/2" bolt with the spring washer near the transom bracket). I found that tightening it made the tiller more user friendly but it's still a battle sometimes, especially when heading perpendicular to the swell.

I'm sure a center console would be a lot more comfortable but I don't want to lose any deck space when I'm diving; it's already cramped enough as it is!

I'd be interested to see some pics of how you rig your boat for diving. I'm always looking for new ideas. I'll post some of mine when I have a chance.

 

[Sea Rider]

Re: What is your speed? - Zodiac Futura Mark III (with a 40HP 2 stroke)

Max speed a bit low, to get down to the problem :

1-Infalte sib and speed undertubes to it's recommended working pressure, asume 3.5 psi on tubes and more on speed tubes, if having pressure relief valves on tubes, inflate untill valve opens up, if not, use a manometer ( a must have issue)

2-Test on flat calm waters or with slight chop, no wind if possible.

3-Place trim angle at middle position (third hole out from transom) and balance mates (1-2) towards bow, full throttle, check if there is excesive water splash sideways or if the splash is flooding the sib at middle (where engine is placed) if the latter, need a small transom rise as Tohatsu do have exhaust tail issues as described on other previous threads.

Note : The engine cav plate and sib hull must be parallel to water sea level when sib is at full plane, adjust trim angle to give this position. Check pic : http://www.pbase.com/locozodiac/image/122043175

Which 40 are you using : Compac C 2 cylinder or standard 3 cylinder engine ?

Happy Boating

 

[0976claxton]

Re: What is your speed? - Zodiac Futura Mark III (with a 40HP 2 stroke)

Searider - Thanks. My engine is the 3 cylinder. Right now the cav plate is almost 2 inches below the lowest part of the hull.

 

[Sea Rider]

Re: What is your speed? - Zodiac Futura Mark III (with a 40HP 2 stroke)

The anticavitation plate must be 10 to 30 mm or 0.4 to 1.2 inches below boat's bottom to meet factory engine's best working parameters. To begin with, correct working pressure is a must, what you can do is, place 1-2 mates at bow, full throttle sib, with prudence check tramson water flow, correct height is the one achieved at calm & flat sea, when water flow passes uslightly under small upper cav plate, where the tail's triangular shape begins. If flow is passing over triangular part and smashing against square exhaust part, will need to raise transom a bit. Tohatsu engines are much prone to give water splash issues than other brands engines. It's a design tail issue.

Happy Boating