Evinrude 90 Hp Etec +5.5 plate boat=What prop?

[Revinrude]

Gday all,<br />I have a new 90 Evinrude Hp etec that the dealer said they would fit the right prop to befor I picked it up. The motor is attached to a 5.5 metre plate alloy deck as it was a boat package thing. <br />Fuel load is normally around 100 litres with two aboard and we usually take the Dish licker as well as a esky and 20 litres of fresh water. <br />The current prop pitch is 15x15. Dont know what brand as there is no other information stamped on it. Looks to be a bargain basement item and knowing the dealers past history would not be suprised if they fitted one that was once used as a door stop in the office??!!<br />Heres the problem or is it?. The motor will only rev out to 4800 rpm trimmed but the motors rev limit is 5500 rpm. The cavitation plate above the prop is just out of the water at this stage.<br />While speed is not everything I feel loosing over 700 rpm is due to bad choice of prop or is it?. <br /><br />I dont trust the dealer as they already sold me the motor tuned to run XD-100 while the oil tank contained XD-50 and then tried to lie their way out of it saying it was XD-100 mixed with XD-50 as they claimed there was a bit left in the oil tank when they poured in the XD-100. Trouble is that the oil in the tank was all pure blue XD-50 whereas the XD-100 is brown in colour. The manual states not to mix oil types but the dealer feels it is ok? The motor was programmed to run XD-100 but had a full tank of XD-50.<br />Anyway the motor looses 700 rpm and top speed according to a Gps is 50 kph or 27 knots. I dont plan on red lining the motor everywhere I go but you blokes know what its like when the weathers coming in, you gotta make hay while the sun shines !. I noticed that the motor rpm runs in sync with the kilometres per hour ie if Im doing 40 kph then the motors doing 4000 rpm, do 35 kph and the motor spins at 3500 rpm etc.<br />Any suggestions for a good selection of prop for this boat would be much appreciated or have the dealers done the righty and fitted the right prop? Or maybe some engine damage has occourred due to the wrong engine oil being used and oil injection programming?<br />One more question. Dose drilling holes in the prop hub make a real difference and would it hurt to try this with my rig?<br /><br />Thanks for your help<br /><br />Tads

 

[Revinrude]

Re: Evinrude 90 Hp Etec +5.5 plate boat=What prop?

Fair enough, sounds a bit to technical for this prop forum concidering it may be an engine fault.<br />I'll post over at the engine forum and see what they say.<br /><br />Tads

 

[walleyehed]

Re: Evinrude 90 Hp Etec +5.5 plate boat=What prop?

Nothing technical (too) to make it go elsewhere....we hang out here too...and you're right, the tank should have been dumped, cleaned and refilled with XD100.<br />I wouldn't prop it yet, until you get 25-30hrs, then we'll look at the RPM. Under the prop nut and washer, the size and P/N should be cast into the housing...get that P/N if possible..all BRP/OMC props have the number there.

 

[Revinrude]

Re: Evinrude 90 Hp Etec +5.5 plate boat=What prop?

Thanks walleyehed. Over 50 hours on the engine already within the first 3 weeks.<br />The only other info on the prop are these few numbers<br /> 174926 15x15<br />From what I can gather, this prop is good for low range, heaps of low down grunt which probably explains why it wont rev out to the 5500 rpm max suggested for the Evinrude? Or maybe it should be the other way round? <br />I might drill some holes to vent the exhaust over the blades to see if that helps top end.<br /><br />Cheers

 

[Boilermaker]

Re: Evinrude 90 Hp Etec +5.5 plate boat=What prop?

Revinrude...Drillin holes to vent is for low end... it lets the prop lose some "bite" by allowing exhaust gasses to leak in front of the prop blade...thus letting the engine spin up into its powerband. <br /> Listen to Kenny (Walleyehed)...He is one of the prop experts here...and he knows a thing or two about E-Rudes too. <br />Make sure the engine is fully broken in first....I know they claim it needs no break-in but... Is the computer setup to limit revs for the first 25 hours or something???<br /><br /> OK...now for MY questions about your post!<br /> I take it " the Dish licker" is a dog---correct??? What is "a esky"??? <br />This New York boy needs a translator!<br />WELCOME Aboard<br />Jim