Water splashing back in boat when driving boat at all speeds ?? WHY?? see pics

[86invader]

]I think i have a 1979 unit. The steering control arm nimbers say it is a 86 and the engine cover that i saw on ebay says it is a 79. Anyways When i went out to the lake last week i noticed that there is water splashing back in the boat when i throttle all of the time. If you notice in the pic (I am uploading) there is a "V" water spray upwards and also water is being pushed behind motor. I have tried to trim it out and still no differences. Any sugguestions? it does it at all speeds. The boat is a 1986 invader with a 150 horse evinrude. Runs awsome just would like to fix this! thanks dave

 

[Haffiman]

Re: Water splashing back in boat when driving boat at all speeds ?? WHY?? see pics

Engine mounted too low, or are you using a Dol-Fin?
A pic of boat at land showing installation height might be better.

 

[emdsapmgr]

Re: Water splashing back in boat when driving boat at all speeds ?? WHY?? see pics

The cowling looks a lot like my 79 Evinrude. The lower cowling is white, which usually a Johnson color. Possible someone damaged the original (white) Johnson cowl and substituted the 79 Evinrude cowl-the crossflow cowls are all pretty much interchangeable. The model number on the transom bracket should tell you what year the engine is. Post it here and we can help with determining the true year of the powerhead. The splashing water may be due to the way the engine is mounted on the boat. A couple of things to check: 1. Make sure you have the correct length engine for the transom height of the boat. If the boat is a 20" transom and the engine has a 25" leg, you will get excessive spray, poor porformance and lousy fuel economy. 2. If you have the correct length engine leg for the boat, it is still possible that is is mounted an inch or two too low on the transom. You can check it while running the boat at planing speeds. The water streaming from under the back of the transom should flow just under the lower unit anti-ventilation plate. That plate is the flat one just above the prop. If that plate is even slightly underwater when planing, you will get the same effect: excessive spray, poor performance and poor fuel economy. If that's the problem, re-mount the engine higher on the transom.

 

[ChillyB]

Re: Water splashing back in boat when driving boat at all speeds ?? WHY?? see pics

Hardly a direct comparison but my 25 long shaft on a short transom 14" hull causes a lot of spray on the transom. So I think the previous posters are on to something with lower unit length.

 

[86invader]

Re: Water splashing back in boat when driving boat at all speeds ?? WHY?? see pics

Hardly a direct comparison but my 25 long shaft on a short transom 14" hull causes a lot of spray on the transom. So I think the previous posters are on to something with lower unit length.

If you are talking about the shaft that goes into the lower unit. (mine is 27 1/4 long) I just changed the lower unit. My boat is 18 foot 3 inches. I will take pics of the back of the engine area. I tink that they are on to something about height!! good call. How would i figure out what it is supposed to be (Level) Anyone??

Thank You Dave

 

[86invader]

Re: Water splashing back in boat when driving boat at all speeds ?? WHY?? see pics

The height thing makes sense! My shaft is about 27 inches long (I just had to replace my lower end) You are sooo right about the horrible gas mileage, I spent 1.5 hours on the water last monday and i used 3/4 tank. More than my 4X4 Durango!! lol I noticed that my motor is Bolted to the transom. If i have to drill new holes should i mount some wood over it and then reclamp and bolt back on? Just wondering. Thank You for all of your help. I will get those numbers tomarrow morn. Oh and i have a whale tale but its not on the boat right now.

 

[emdsapmgr]

Re: Water splashing back in boat when driving boat at all speeds ?? WHY?? see pics

Typically, when any boat is setup, either by the factory or by the selling dealer-they will drill the engine mounting holes in the transom. There is a standard drill template that is normally used. This locates the holes properly in the transom-generally correctly for most all engines. The engine has a number of holes in the right and left transom bracket which will permit it to be mounted slightly higher or lower on the boat, depending customer preference. It is not unusual for an engine to be remounted higher or lower. Those holes usually permit the engine to be remounted an inch or two higher or lower. If you need to remount the engine more than those few inches, you may have to consider the purchase of a special transom bracket which will mount between the engine and the transom-to give you more adjustment capability.

 

[Haffiman]

Re: Water splashing back in boat when driving boat at all speeds ?? WHY?? see pics

The height thing makes sense! My shaft is about 27 inches long (I just had to replace my lower end) .............................

This smells of a 25" engine on a 20" transom.

 

[Haffiman]

Re: Water splashing back in boat when driving boat at all speeds ?? WHY?? see pics

When looking closer at the pick, the engine seems to be 'lifted' to the max on the std holes.

 

[rtek816]

Re: Water splashing back in boat when driving boat at all speeds ?? WHY?? see pics

Ever weigh the boat??? Soaked foam can add hundreds of pounds of weight causing the boat to sit lower in the water.

 

[emdsapmgr]

Re: Water splashing back in boat when driving boat at all speeds ?? WHY?? see pics

Take a picture of the lower unit of the engine and sight down the antiventilation plate towards the transom of the boat. Post it. Any extra weight of the boat should have no effect on your problem. That extra weight does not change the engine mounting relationship of the engine to the transom.

 

[rtek816]

Re: Water splashing back in boat when driving boat at all speeds ?? WHY?? see pics

I'll digress to the experts. Just my experience that when I replaced the floor and foam, at idle my 21' starcraft sits a full 4" higher with the same payload. Used to take water (1-2' waves) through the splashwell drains at idle trolling speed. Less splash also from the speed sensor and transom mounted transducer once I lightened her up. Let's see some pics.

 

[nwcove]

Re: Water splashing back in boat when driving boat at all speeds ?? WHY?? see pics

would definitely like to see pics of the the rear of your boat, cavitation plate height in relation to the lowest part of the hull. is there anything else hanging down ......looks like a swim ladder attached?

 

[86invader]

Re: Water splashing back in boat when driving boat at all speeds ?? WHY?? see pics

here are the pics i took today. It looks like its too high?? its all the way at the top of the mounting holes (No more adjustment) let me know what you think. Thanks daveView attachment 115606View attachment 115607

 

[Haffiman]

Re: Water splashing back in boat when driving boat at all speeds ?? WHY?? see pics

here are the pics i took today. It looks like its too high?? its all the way at the top of the mounting holes (No more adjustment) let me know what you think. Thanks daveView attachment 115606View attachment 115607

Attachments not working. Load on Photobucket or similar, post the link.
The question is not how high the engine is mounted on the transom, but how deep down the gear case is! The anti ventilation plate above propeller must be at least 1" ABOVE bottom.

 

[86invader]

Re: Water splashing back in boat when driving boat at all speeds ?? WHY?? see pics

would definitely like to see pics of the the rear of your boat, cavitation plate height in relation to the lowest part of the hull. is there anything else hanging down ......looks like a swim ladder attached?

Here are the pics i took today )It looks like its to high) let me know what you think. Is the engine too long for the boat? I couldnt put the motor all the way down cause it will hit the ground. But to me it looks like its too high. Let me know thanks dave

 

[Haffiman]

Re: Water splashing back in boat when driving boat at all speeds ?? WHY?? see pics

That is a 25" engine on a 20" transom.
Two options:
1: Change to 20" engine.
2: Get/make a bracket that may get the engine min 4" higher.

 

[86invader]

Re: Water splashing back in boat when driving boat at all speeds ?? WHY?? see pics

What is a 20inch transom? Sorry im not to literate on boats. What will happen if i continue to use the current engine on my boat? Will it break the back of the boat? Do they sell the brackets? if so can you send me a link? I prefer to do it rite, If i cant afford a new motor. Thank You

 

[emdsapmgr]

Your engine leg is too long for the transom of your boat. You won't be able to make up a 5" difference unless you add a manual jack plate. CMC and a number of other jack plate manufacturers make them in assorted sizes, shapes and setbacks. Look them up on the internet. Here is a link to manual jack plates: http://cook-mfg.net/cart/index.php?...=10_12&zenid=93aa54de973a677fda05225b7adb3d65

 

[Haffiman]

Re: Water splashing back in boat when driving boat at all speeds ?? WHY?? see pics

Transoms are made to specific heights. 15" = short shaft, 20" = Long Shaft, 25" X Long shaft. You may even get some 30".
All engines with Trim and Tilt use 20" or above. Most runabouts and smaller use 20", deep-sea runners, and boats in the 20" above range of 'newer' models often use 25". In some cases people want to get the engine higher than the transom is designed for, sometimes even lower. On my old Boston Whaler 17 Outrage with 25" transom, I used an 'inverted' hydraulic Jack Plate and was able to use both 25" (standard) and 20" engines for testing. However it puts some extra strain on the transom, be careful!!
Google 'outboard jack plates', go to 'images' and you get an idea. Be aware that lifting the engine means changing the center of gravity and may make the boat a bit more unstable.