HST Skier/Yamaha 200 Setup

Hi Randy,

It appears as thought you have spent a number of hours in the seat of some HST's and was wondering if you could help me with some questions.

I have a 1989 HST "skier" (that name is on the coast guard tag) which I'm powering with a stock 200 hp Yamaha Pro-V with an exhaust tuner and nose cone; the motor is a 1993.  I'm running 12 inches set back and have my prop shaft located approximately 2+ below the centre hull.  What height do you recommend I run this engine for optimum high speeds?  You should know that I'm running a 14 1/4 by 29 round eared and am spinning @ 6300 rpm.  How high can I safely rev this engine?  I'm guessing I'm running 85 mph; sound right? Is this set up appropriate and if not, what can I do to squeeze out a touch more top end? It's a manual jack plate by the way.

Thanking you in advance,

Colin Bodley
Winnipeg, Manitoba, Canada

 

Colin,

Sounds like you have a clone to my old HST ski boat. Just so you know I think the "skier" part of the coast guard tag was something they did to make the boat more insurable and to appeal to a broader base of people. Back when I sold them a few "skier" models were tagged but the boats were no different. The word skier tames the "speed police" down a bit. I still have some "fill in the blanks" coast guard tags for Hydrostreams myself. You never know when you might need one.

I used to run my HST / Yamaha with the propshaft 1/2 to 5/8 below the pad. Two reasons: 1 the boat needs the lift and going higher just throws more water but no more thrust. And 2, the Yamaha gearcase is not the strongest in the world. The higher it's run the more parts you'll wreck My old boat would run 95 and some change and do it with 2 people if you wanted to give rides. Sounds like you have an SRX prop and that should work good. I ran my Yamaha as high as 7200 but it makes most of its power close to 6000. If you could spin that 29 at 6600 or a little better you'd be about like my old rig. I found that moving the motor up and down on the jack was kind of a waste once you found the sweet spot. Your manual jack is perfectly fine. If you have a large rooster tail and a lot of steering torque go down in height till it evens out. You can go up until it pulls hard to the right on the wheel, that is when the prop is losing bite.


                                              That should get you close and over 90!
                                                                     Randy

 

 

Please submit whatever questions you have to IHRTechTalk@yahoo.com.  All questions and answers selected will be displayed on this page as they come in.  Note: though all boaters are welcome, priority may be given to I.H.R. members.  Randy can not be held responsible for any advice given.  Though his information and expertise is second to none, he has no control over what you do with your boat.  It is up to you to boat safely and act responsibly, and his advice is only to be used as a guidance for your high performance boat/motor of which you are the one responsible for the risks involved.

Thanks,
Mark C.

 

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