2004 Trophy 1802 115 4 stroke, re prop

[lj973gm]

Purchased a 2004 trophy 1802 with a Mercury 115 hp 4 stroke beginning of this year and was looking to re-prop for a change in the way the boat performs.

Currently running stock prop which is a a 15 pitch 3 blade aluminum

Boat has trim tabs

Verified on GPS as follows

4.500 rpm 25
5.000 rpm 30
5,800 rpm 36

It is a 18' off shore cuddy typically with 2 people and about 30 gallons of fuel, out on Lake Michigan to cruise and to fish. Gas mileage is really good and have no complaints.

Complaints are as follows:

Poor steering in harbor, I came from a inboard so I am not sure if it is me or the boat but the harbor is not a fun place to be in this boat.

Slow to plane and need rpms to be about 4K to stay on plane in waves of 2-3 feet

I would give up a couple of mph of top speed to see nice mid range and better planning. Overall the boat feels like a bobber in the water and seems top heavy, it gets pushed around easily by light drift and wind, not sure if this is the boat hull or boat style. My old boat was much more planted in the water and easier to steer, it was a 18' cuddy which I know sat lower in the water, which is the likely reason.

Most calculators when selecting overall performance show going to a 3 blade 16 or 17 pitch and a 4 blade with 15 pitch.

Anyone have some recommendations on what will meet my needs.

Any more info please ask and I will provide if I can.

 

[lj973gm]

Re: 2004 Trophy 1802 115 4 stroke, re prop

One other point I forgot to mention is on my previous boat you could hit a 3+ foot wave and it would hit the wave and not drop much in rpm or speed and keep on chugging.

In my new boat if I hit a wave my rpms drop way down almost a bogging sound and it looses a bunch of speed the is the reason I need to be a 4K rpm to stay on plane.

I know some props state they provide bow lift and other state they provide stern lift.

Would I be looking for bow or stern lift style prop to solve this situation. Actually now that I think about it my previous three boats did not show this problem when hitting waves. A bit puzzled on this one.

 

[steelespike]

Re: 2004 Trophy 1802 115 4 stroke, re prop

Perhaps the boat has a stern weight bias. Is this your first 4 stroke?
Do you trim all the way down for hole shot?
Perhaps some undetected water in the bilge? "poor steering" Do you mean it wanders at no wake speed?
Is the hull a deep v or a relatively flattened bottom?
Are your tabs active or passive like smart tabs?
It appears you need a stern lifting prop.Usually suggested to try a 4 blade prop Solas props have a good reputation.
also suggested to drop one inch in pitch going to a 4 blade.

 

[lj973gm]

Re: 2004 Trophy 1802 115 4 stroke, re prop

Perhaps the boat has a stern weight bias. Is this your first 4 stroke?
Do you trim all the way down for hole shot?
Perhaps some undetected water in the bilge? "poor steering" Do you mean it wanders at no wake speed?
Is the hull a deep v or a relatively flattened bottom?
Are your tabs active or passive like smart tabs?
It appears you need a stern lifting prop.Usually suggested to try a 4 blade prop Solas props have a good reputation.
also suggested to drop one inch in pitch going to a 4 blade.

Very few hole shots happen in all honesty, typically cruise about 25 miles and then do my needs and head home. Yes it is trimmed down the when taking off. Wish I would have timed how long a hole shot takes. I am going out Sunday so I can try to get more facts then.

This is my first 4 stroke OB, always have had IO's but they did not make this model in a IO and I needed one that would fit in my garage so this fit my storage needs. It did have a 9.9 kicker out back as well that I have taken off to see it it changed how the boat acted. After taking it off it was really not noticeable if it was there or not. I believe it spec to be 89 pounds.

Have checked for water in the bilge since it was a common problem on specifically the 1802 model but none is present.

In terms of poor steering it is pretty much non existent in reverse, and at idle, no wake speeds when in forward while in harbor it is a overall pain to get the boat to steer if there is a light breeze even. This is in a fully sheltered harbor just the breeze causing it to be pushed around so easily.

It is a deep hull boat. Here is a link to my specific model, http://www.trophyfishing.com/archive.asp?modelid=34857

They are smart tabs style/passive and are set to max down/last setting by previous owner. What are the pros and cons to these while out at speed.

 

[steelespike]

Re: 2004 Trophy 1802 115 4 stroke, re prop

if the tabs are set too aggressively it could cause the boat to lay down too much and waste fuel both from too much hull in the water and the drag of the tabs. Being full on the tabs may interfere with steering in reverse.
You might try releasing the tabs to see how reverse responds also might try hole shot
without them.
As far as being pushed around Does it have a good keel the length of the bottom?
Its disappointing to have the poor hole shot with the tabs.
The smart tabs people are usually pretty helpful. Perhaps a different model.
Is the anti vent plate(just above the prop) about even with the bottom of the transom.
the boat is pretty tall could have a lot of"windage"I think they call it.
You might try posting the problem in the boats only forum.
perhaps there is a Trophy forum you could discuss it the on.
Do you think your hole shot is measured in seconds or minutes?