'84 Vegas/Mariner 200

I am new to these boats and have a few questions.  I have a 1984 Vegas with a 1984 Mariner 200.  First do you recommend removing the oil injection on my 84 Mariner.  I am having problems with it and was told it was best to remove it instead of trying to fix it.  Secondly I am running a Powertech 4 blade 27 inch pitch prop at about 67mph (speedometer).  I still have throttle left, but it is redlined.  The top of the prop (outer diameter) when level trim with the boat is even with the bottom of the pad.  Which way should I go with the motor?  Any help would be appreciated.




Your numbers don't add up.  A 27 inch prop at 6000 rpm should be running almost 80.  Either your prop really sucks or your speedometer is not reading right.  Your engine height sounds about right.  You may remove the oil injection, but at the rpm you are running, it works fine if all the sensors are in place.  Unless you are turning the motor 7000 rpm, there is no advantage to removing it.  Try and get a 14 1/2 x 26 chopper and rerun the boat.  If the speed comes up, we know it was the prop.  If not, I would look at the gearcase shape and gear ratio to see if there are any problems.  Try these things and see if your boat improves.  If you wish to keep the injection, have someone repair it with original parts.  If cost is an issue, you can remove it and mix the fuel at 40/1.  Hope this helps. 




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.

Mark C.


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