90hp FICTH tilting?

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revismi

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Apr 3, 2003
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Hello,<br /> This a hard one to explain. I recently replaced a 90 hp johnson with a 1999 evinrude FICHT. THe problem is when I am 3/4 throtle the engine is spraying a 20 ft rosster tail at a little over half trim and turning 6300 RPM's, but then it act like it changes gears, the rooster tail drops, RPM's drops 800, and top speed improves? It almost seems like the engine tilts down without me touching the trim switch. I was curious if anyone has heard of this? I am thinking the prop is not right? Any suggestions are welcome.<br /><br />Thanks.
 
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Dhadley

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Feb 4, 2001
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16,978
Re: 90hp FICTH tilting?

Are the two mounted at exactly the same height? Where is the AV plate in relation to the bottom? What brand/type prop? What hull?
 
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revismi

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Re: 90hp FICTH tilting?

Thanks for the reply. The first motor was a 98 model johnshon 90 hp and this one is a 99 model evinrude 90 hp. The dealership swears they are mounted same way. I am not sure on the A/V plate, but will check tonight. They did have to put a another prop on this envinrude because the one from the johnson was turning too many RPMs ( went from the aluminium to a stainless). I have the box, so I will look at the pith and diameter tonight. I do know it is a Raker from OMC. The boat is a 98 model 268V Stratos.<br /><br />Thanks again
 
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Dhadley

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Re: 90hp FICTH tilting?

OK. So we're saying that we changed the motor but the propshaft is in the same position to the bottom but we changed props. As a guess I'd say we have a prop issue. It almost sounds like that Raker was redone using an SST pitch block. <br /><br />Have you got anyother props to try?
 
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revismi

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Re: 90hp FICTH tilting?

I don't have another prop to try. Is it possible the tilt and trim has air making the engine slide down ( agout 1/2 inch) when under troque?
 
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seahorse5

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Re: 90hp FICTH tilting?

I'm with DHadley, it must be a prop problem. A Raker is made to ventilate on take-off to get the revs up quickly, then it "hooks up" and the boat speed increases. Unless the boat is capable of over 50 mph, it is a waste of money to use on most boats.
 
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Dhadley

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Re: 90hp FICTH tilting?

Is the motor actually moving? If so you should be able to see it do so. Or is the prop just simply hooking up after a few seconds? <br /><br />Are you sure there were no other changes made? Nothing added (speedometer, depth finder, etc)?<br /><br />Was there anything on the old lower unit thats not on the new one like a plate or fin of any kind?
 
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Dhadley

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Re: 90hp FICTH tilting?

I just re-read your posts again. It sounds like you bought the motor from a dealer. If so they should have other props to try. After all you paid them, one way or the other, to rig the motor on the boat. <br /><br />Now, if you said you went from a Raker (at its correct X dimension) to an aluminum without changing the X dimension (mounted running height), I would expect the motor to act somewhat this way. But you said you went from an aluminum to a Raker at the same X dimension -- which should be too low.<br /><br />Is the Raker new or rebuilt or worn out?
 
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revismi

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Re: 90hp FICTH tilting?

Thanks again for the advice. I think yall explained my problem better than I did. The "hooking up" is exactly what it sounds like. The problem is sometime it takes forever, especially with two people in the boat. And Dhadley, it looked like the engine was actually moving down ( a small bit) and when that happened the rooster tail disappeared and speed was better.
 
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revismi

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Re: 90hp FICTH tilting?

Thanks again for the advice. I think yall explained my problem better than I did. The "hooking up" is exactly what it sounds like. The problem is sometime it takes forever, especially with two people in the boat. And Dhadley, it looked like the engine was actually moving down ( a small bit) and when that happened the rooster tail disappeared and speed was better.
 
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Dhadley

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Re: 90hp FICTH tilting?

If the motor is actually moving within the trim range then thats a problem that the selling dealer should take care of. Once you trim a motor it should stay where it is. If you get into the tilt range at slow speed and then accelerate, yes the motor will move down to the trim rams.<br /><br />If you are accelerating with the motor at 1/2 trim then it may take a bit longer to hook up as you describe. You should get on plane with the motor in and trim out as the boat settles on plane. <br /><br />Good luck!
 
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revismi

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Re: 90hp FICTH tilting?

Sorry, I was not finished but the browser cut me off and posted twice for some reason. I did buy the engine from a dealer and have taken it back once already because one blade come completly off of the first prop (raker, same everything). The factory sent a brand new replacement. Nothing else was added to motor or boat, just the engine. Before the 90hp jonhson blew for the second time, top speed for the boat was about 42MPH. This motor( when it hooks up) is about 52MPH. The problem with my dealer is he is about 1 and 1/2 hour drive away. I am trying to be more educated this time.<br /><br />Thanks
 
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