150 evinrude 1996 WOT

[Barramundi NQ]

Hello iboaters,

Can someone tell me what the WOT is for a 1996 150HP Evinrude 2.6 litre V6 is?
At full throttle my 21in prop gives me 5200 rpm at WOT with the trim right up on calm water.
At 3000 rpm it falls off the plane if it hits a biggish wave. My boat is a Cox craft Rum Runner 5.0m .

Help

Kerry

 

[YoungMind]

4500-5500

 

[Barramundi NQ]

Thanks youngmind.

So with my boat at 5200 rpm, my concern is that the prop is too big 21 in pitch. I'm thinking I need to go to a 19 in Prop to get the revs in a better range and help the boat from falling of the plane at 12-15 knots. I'm I on the right track?

Kerry

 

[SkiDad]

that prop seems right but running a 19 would not hurt it - not sure it will fix your issue but you could try trimming down just a little when just cruising at 3000

 

[dingbat]

The planning speed of the boat is a function of its hull design. Trim tabs and a 4 blade prop would help but don't expect miracles.

 

[steelespike]

So we have a 16 ft boat with 150 hp.21" prop makes 48 at 5200. Doesn't strike as a boat that does well at vastly reduced speed.
How is the hole shot? How does it respond to added weight?Water sports?
A simple change to a 19" may help the ability to stay on plane.And improve these things, might cost a little top end.

 

[Barramundi NQ]

Hi Guys

Just to clarify, the boat is a fishing boat that I use for reef fishing 25-45 km offshore. Trimming the bow down at lowest planing speeds (12 knots) means more revs to hold the plane and it is easily knocked off the plane by a wave near head on. Holeshot is good, it pretty much jumps out of the water. However I believe the 21" prop means it is making the engine work a little harder. I would describe it like a diff in a car, tall diffs ( less than 3:1 ratio) are what I call Highway diffs. Going the other way a diff over 4:1 is like a drag car, hooks up off the line (holeshot) but you can over rev your engine even in top gear.

If what I'm describing is an accurate analogy, then my boat struggles to get over 4500 rpm unless fully trimmed up and this can only occur in calm water.......a very rare occurrence offshore.

Even as I'm writing this, I think I'm convincing myself to get a 19"prop (even as a back up). I have a soft floor in this boat, so I will be joining the ranks of many who have gone before me in the journey that is stringer and floor repair. Undoubtedly I will have to replace the transom too, as once these repairs start, 99.99% will find more than you think is wrong. I believe that if I start with the idea that transom needs to be replaced, I wont be shocked when I pull it apart.

I will start a thread in due course.

Thank you iBoaters!

Kerry

 

[steelespike]

A 19" prop won't hurt and should help your problem.
If the floor is soft and transom possibly rotten there is no telling what shape the bottom is underway and the transom may be distorting as you trim.
Keep in mind if the hull is compromised it's not out of the question it could fail while off shore. 45 km is a long swim.

 

[Chris1956]

Gee, I run the same motor on a heavy 21 footer. I run a 19P prop, and have no issue with planning. Top speed is about 40MPH. It sounds to me like your motor is down on power, or you have some soaked foam weight in that boat. You should be able to really spin that 21P prop on a 16 footer. She should stay on plane easy, at any RPM above 2300-2500, with that 150HP.

 

[Barramundi NQ]

Hello Chris

I'm sure the old girl is a little water logged. The engine has only 150 hrs on it. My uncle owned the boat before and he used it twice year, and I was in it half of those times. My uncle is Aboriginal and he and my cousin used the boat mostly for catching sea turtles, which is another way of saying that it has been hung up on a few reefs during its lifetime. The keel has some significant wear from sand beaching on the sand cays here on the Great Barrier of Cairns in Australia.

The last service it had, the shop mechanics said that my motor was like brand new, mechanically, that is under the cowl, but has suffered from typical North Queensland's hash UV damage.

Re The Foam? I'm not sure there is any (but what the heck do I know!) all the floor seems to be hollow, but when I begin the stringers etc I'll probably be proved wrong. There have been a few repairs over the years, and the last one showed no foam in that area which was nearly directly under the Port side floor in front of the seat box.

Appreciate the thoughts

Cheers Kerry

 

[Barramundi NQ]

Chris

BTW my top speed is 85 kmh. 52-53 mph. This is only ever achieved in the harbour. WOT with the motor hard against the transom, gives my around 4500 rpm. Obviously trimming until just before the prop starts slipping (and a small rooster tail forms LOL) As it used as a fishing boat and the waters here are never calm for more than 5-8 days a year, top speed is never used on the fishing trips, so I'm more convinced than ever to source a 19 in prop.

Of course after the repairs needed soon the boat may be lighter? or at least much more rigid and watertight, I might have a chance of using the power. Here in OZ my size boat for fishing commonly sees a 90-115 hp on the back of a 16 t glass boat. Would you believe that the manufacturer rates my hull to 200 hp! At flat bicky (that's 'full throttle" aussie slang) a 200 hp would leave about 6 inches of hull in the water and the prop!

Any way thanks for your input

Kerry

 

[Barramundi NQ]

Chris

BTW my top speed is 85 kmh. 52-53 mph. This is only ever achieved in the harbour. WOT with the motor hard against the transom, gives my around 4500 rpm. Obviously trimming until just before the prop starts slipping (and a small rooster tail forms LOL) As it is used as a fishing boat and the waters here are never calm for more than 5-8 days a year, top speed is never used on the fishing trips, so I'm more convinced than ever to source a 19 in prop.

Of course after the repairs needed soon the boat may be lighter? or at least much more rigid and watertight, I might have a chance of using the power. Here in OZ my size boat for fishing commonly sees a 90-115 hp on the back of a 16 t glass boat. Would you believe that the manufacturer rates my hull to 200 hp! At flat bicky (that's 'full throttle" aussie slang) a 200 hp would leave about 6 inches of hull in the water and the prop!

Any way thanks for your input

Kerry

 

[Barramundi NQ]

Chris

BTW my top speed is 85 kmh. 52-53 mph. This is only ever achieved in the harbour. WOT with the motor hard against the transom, gives my around 4500 rpm. Obviously trimming until just before the prop starts slipping (and a small rooster tail forms LOL) As it is used as a fishing boat and the waters here are never calm for more than 5-8 days a year, top speed is never used on the fishing trips, so I'm more convinced than ever to source a 19 in prop.

Of course after the repairs needed soon the boat may be lighter? or at least much more rigid and watertight, I might have a chance of using the power. Here in OZ my size boat for fishing commonly sees a 90-115 hp on the back of a 16 t glass boat. Would you believe that the manufacturer rates my hull to 200 hp! At flat bicky (that's 'full throttle" Aussie slang) a 200 hp would leave about 6 inches of hull in the water and the prop!

Any way thanks for your input:happy:

Kerry

 

[Barramundi NQ]

I Hit post and a box it wasn't able to contact server....so I hit post 2 more times.....sorry newbie here

 

[dazk14]

What is the specific make/model of the propeller you are using?

Aside form it being a 16' boat, your boating conditions beg for a 4 blade prop. A 19" Solas Amita runs about $110US.

You will lose some top speed, but rough water performance, will be noticeable improved.

 

[Barramundi NQ]

Hello daz

I'm sorry the prop has no visible markings to tell me the brand or design. I had a SS prop but the hub went (not fixing as its a little banged up). The shop I got it serviced had a aluminium prop new on the shelf and offered it for $150 AU. That's cheap as those props are usually $200 AU or more.
I've tried to upload photos a couple of times but keep getting the dialogue box saying the photo is bigger than the 2 mb limit. I've set my phone camera to sizes well below 2 mb (last photo I tried was 1.36 mb) and it still said it was above the 2 mb limit....so I don't how to overcome that....

So back to the prop....it's a 3 blade aluminium 14 3/4" x 21"pitch. It's in good condition, no chips or nicks. Motor is in excellent condition. Boat is an 1984 Cox Craft Rum Runner, made on the Gold Coast, Queensland, Australia. Boat is 5.0m (16ft). Transom was replaced 9 years ago and appears sound. Hull is flexing due to rotten stringers and the floor is soft in one spot.

Let me know if you need more info....I do like the idea of a 4 blade prop for bite and for rough weather. Although I only head out in 5-10 knots, we all know that we never come home in the same weather or water. Currently both the boat and me are out of commission. Boat not safe for outside trips, and I've just had surgery on my left heal. The surgery is called a sub-talar fusion. So crutches for 3 months....yee har! Going nuts and I was hoping to use this time to work on the boat.....Have the time, but not the funds.:facepalm:

Cheers

Kerry

 

[Barramundi NQ]

It is a quicksilver aluminum prop 14.75 x 21p, from memory. (I'm not able to walk around much due to an ankle surgery)
Thanks for your time