Glen-L.com

When I bought my Merc 500 on E-Bay, I ordered the owners manual, parts manual, and repair manual from East Coast Marine. It was lucky that I did that before I started the construction because the owners manual listed my 500 as having a 16.5" shaft and not the 15" I thought I was getting. As a result of finding this information, I redrew the transom pattern and raised the cutout up to allow for this and made it wider to allow for steering linkage and tipup. Very strange and confusing why Mercury had this variant in the transom height requirements. I guess I was lucky that I discovered this before I started building or I would have built the cutout as drawn in the plans.

If you have your motor already and are building a Zip, check the recommended transom dimensions in the owners manual. If you don't have the manual, get it before starting construction.

Chris, I'm sure this can be resolved satisfactorily. Kinda like Phase I flight testing your home built plane. Always something to modify. It will be fine.

Roberta

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Roberta
Built Zip "Oliver IV" and Super Spartan "Jimmy 70"

What they have won't hurt anything,just throws a little spray.

They just need to tweak it some to get a little more efficiency and speed out of it....fine tuning if you will.

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Boat building can best be defined as an endless series of
tragedies obscured by the occasional miracle, followed by a good bottle of beer.

Don't Dream Your Life, Live Your Dream

The most important number for your transom and all transom builds is the running deminision since the transom when placed on an angle reduces the overall vertical height. I understand the issues of the control cables coming through the well. I have just gotten in from the water and will addres this further for you. IN the mean time measure the actual inches from the transom cap to the bottom centerline keel.
Can you get a better shot showing the starboard side and the front direct on of the motor setup? Don't count yourself out of this bit of tweaking right now. You may not know that you can also set the helm up with it coming in from the port side depending on the length of the cable. Of course this also depends on the interior bits and pieces. Spray water while not a total disaster also reduces speed and in rougher water can soak all your motor parts in turns. IN salt water too, even though you may never boat in it, will destroy engines with the mist thats sucked into the cowlings, forget about the constant covering of the hardware on the exterior.. [This is for the benefit of others]

Dave, oh so true! I will be out playing with the big dogs and not watching from the porch, thats what counts.

Roberta, thanks for confirming the 16.5" measurement, I knew I heard that somewhere.

Mike, I measured the transom from where the motor rests now down to the center of the keel is 15-1/2" So if Merc made these for 16.5" transoms then you can see why I think the tilt is more of any issue than one measly inch of depth causing all the spray.

I think this pic is the one you wanted Mike.

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"Nothing screams poor craftsmanship like wrinkles in your duct tape."

Well when you build an angle on a transom, the running distance has to be more than the vertical height from the water surface to have the equivilant distance. I looked at the black area that shows the steering cable coming through the well side and it looks like that is quite a bit of black above the cable now. is there a void there? If so with the additional wood showing above the wing screws holding the motor on the transom you should be able to lift the motor up at least an inch and still have solid wood for the flats connected to the threaded rod. It also looks like you have enough area in the slot for the steering rod on the port side. SO lets start there. Whats above the area on the starboard side where the cable enters the splashwell area?

If that was my boat, I would not hack up all that beautiful workmanship. Tinker a bit with the tilt pin to see if that helps. If not, why not look for an older Merc with the 15" shaft and run what you have until you find one. That way all your hookups will match up and you won't need to rework everything. I'm sure you could get top dollar for your motor from someone needing a 40 hp. They will have a heads up on the necessary transom dimensions.

All the Best,

Roberta

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Roberta
Built Zip "Oliver IV" and Super Spartan "Jimmy 70"

Chris,

Have you stopped smiling yet? You will rarely feel a better feeling than first launch - especially when all goes well.

Congrats! You did a great job and I look forward to a ride in just a few days.

KB

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"I'm not trying to get it perfect. I'm trying to get it finished!"
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I see no hacking of the boat at all in the last photo and would never suggest this for his problem at all as long as the tops of where the cable exits into the splashwell area is open with just a filler plate that shows black. Knowing that he has also not drilled a bunch of holes to hold his engine on now, its really a no brainer unless there is more to the story here thats not been shown.


Trimming the leg away from the transom only makes matters worse especially if the boat is running on a nice trim with the nose slightly up. When a cavitation plate is below the bottom of the boat and throwing water and you trim the leg back further away, all you do is cause the top of the plate to drag in the water if the back end of the plate is above the front end on a level plane.

Please read about transom angles and running distances versus vertical distances of outboard motors from the inside of the hanging bracket to the top of the plate.

The more angle on the transom out of 90 degree upright from the water plane the more running distance that you need if your engine hangs snug against the top of the transom cutout. He has ample wood above the flat metal that fits snugly against his wood on his hangers as long as he has room on top of the cable exist hole.

I actually use several exist ports to allow the cable and controls going to the engine which also allows servicing seperate bits and pieces when need be.

My imput here has only been in response to chris's comment and interest in the area of spray and in no way any intent to discredit the build. Regards

Thanks Kev, yes, its a blast, extra spray and all. I really didnt care at the time

Mike, Not sure what you are getting at with the transom angle and vertical height. I have built it the way it was designed with the extra for the angle and even a little proud so that should be more than sufficient?

Behind the black rubber are not voids, the holes that are there are only big enough for the cable and nut. The black rubber is to keep any water splashing in the well from easily splashing into the bildge. The black covers are oversize so they adhere to the motor well sides. It looks like there is room above but the decking is 5/8" of that extra you see.

I would have to hack into the motor well frames that are behind the motor well sides and black covers which I already have holes half way through those frames for the cable as it is. So moving the motor up at all, even 1/2", would require cutting through those frames entirely and the motor well would only be supported by the decking above it. That 1/2" is all I could raise without cutting into the deck. I cant see that being worth the trouble.

Lets step back and look at the big picture. I am one silly little inch away from the recommended height of the motor. Im just going to have to try the 2nd tilt notch next time and if that doesnt help the spray and drag Im not sure its worth cutting into the motorwell frames and cutting a notch in the deck by the motorwell for the cable and arm just to get 1" higher.

I hope you understand my skepticism that the 1" is the problem. I dont have any experience in this area and I havent seen or heard of anyone else making adjustments for this and many folks have these older Mercury motors on glen-l boats with 15" transoms.
I was just hoping to get this figured out so I could go ahead and add the bolts to the motor before heading down to G4.

Wish I could go do some test runs tomorrow but I also need to adjust those bunks so I dont catch my cutwater on the trailer again during the next launch.

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My Zip build log...
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"Nothing screams poor craftsmanship like wrinkles in your duct tape."

The distance of that cable and the cable itself is somewhat forgiving if you only give it a shot. You will find that unless you swamp your boat in reverse, water will rarely enter into the interior of your boat on the well sides. Whitling is probably not even in the cards either, but I do not know that from here.


My only intent was to respond to your concern and also added some general information in hopes that others coming along would pause a bit and look at the details such as how transom angles affects vertical distances. A 15 inch motor or even a 16.5 inch motor requires a longer running distance on the transom when placed on an angle then the vertical numbers of your particular engine.

These particular numbers also varies with year, make and models for time eternity too because of engines being sold to different markets. I also will say that the so call misunderstanding here that seems to have resulted from some extra babble may have caused more harm than good . There is nothing silly at all about the one inche difference here.

As far as anyone else? Maybe, ,maybe not, but it just so happens that we are dealing with the present and with this particular known. Your engine is just too low and angling the leg back further away from the boat has never ever improved the performance and overall handling for me anyway. When you angle the leg back and the plate is too low, you only catch more water while removing some ability for the cavitation plate to hold water to the prop tips causing the engine to potentially cavitate too.

but anyway we are not making any headway here and I do not wish to further take away from your beautifull project. Have a good trip. If you have any interest later in revisiting this issue, feel free to let me know.

Mike,
I sure appreciate you voicing your experience. I hope I dont sound disrespectful. I've been hoping some other folks with similar set-ups would chime in. I just cant go making a big change like that without more information and/or test runs.

At this point I have mixed information from folks all whom are much more experienced than me. 2 have said the tilt change worked for them in similar situations. For the record I agree it is too deep but just not certain that is solely the reason for the spray. So you can see my predicament. Nobody would alter a boat to that degree until they either have information pointing in one direction or their own test runs and experience build to form a conclusion.

I think I see what you are saying about the angles though. In other words, with the angles the actual discrepancy in height could be more than 1", correct?

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My Zip build log...
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"Nothing screams poor craftsmanship like wrinkles in your duct tape."

Okay for some clarification,,,,,,
My responses has never suggested any major alteration. Read my reply to Roberta. My replies and follow ups was an attempt to gather more information from afar. The only thing that I ever suggested was to loosen two hanger "wing nut" types and see what happens with a gentle nudge in the upward direction with whatever lifting method that you used to install the engine on the transom everything connected. I think I saw a cherry picker at some point.

BUt it could even be a simple method of blocking up the skeg after cranking the hitch wheel down and then back up a small amount pushing the front of the boat up which gently adjust the engine up on the transom if you do not even have a cherry picker. You cannot compare to what others have done if you get right down to it. Spraying water from cavitation plates is a common problem in even cokie cutter production boats when even repowering takes place too.

Whatever length and whatever brand of engine plays no real role in this as they come from one common theme, or at least has been my and numerous others observation. But at the end of the day, this is just an online forum and opinions can surely vary depending on what other people have witnessed. Gotta run. Drive safely and have a good and enjoyable trip. Later

Here's a pic that may or may not clear up some stuff:

http://www.onlineoutboards.com/referenc ... easure.gif

I believe what Mike was trying to convey is that the height measurement is vertical from top of transom down to the bottom of the boat, but where some people get confused is they make the transom from the cutout down to the keel following the angle of the transom which results in a transom height too short and the motor too deep in the water.

We are not implying that you did this Chris, just hope to clear this up some for future builders that may read this.

Like I said before,try the tilt pin setting, then if you still want to mess with the height,do that later.

You built a beautiful boat and it looks like it rides and handles great.

I would just bring the stuff to drill & bolt the motor at The Gathering....we can mess with it there if you wish, but not to worry.

_________________
Boat building can best be defined as an endless series of
tragedies obscured by the occasional miracle, followed by a good bottle of beer.

Don't Dream Your Life, Live Your Dream

Warren,

Thanks for the image. I guess it only adds to my confusion. It says for 15-17" you need 15" Im within that 2" range but yet my motor is still too low. I just cant figure out how my motor wound up low enough to cause a problem. If I were measured at 14.5 on my transom" then I would be outside that 2" range from the 16.5" we now know Merc recommends. But I am at 15.5" so why does the motor look so low I wonder?

Mike, no problem, only reason I felt you were implying to cut is because I literally have no room to go up with the motor even 1/4" without cutting motorwell framework. Looking at it again this morning I think I now see an area on the lower unit where water could be made to spray like it does if it hits it right. I think raising the motor 3/8" would cure that if its the culprit. I would have to get in there with a drum sander on my drill and cut deeper notches in my motorwell frames where the cable and rod link go through.

I'll see you guys there at G4 and we can look at it in person. Im sure we will all be on the same page then. Sorry if I rubbed anyone the wrong way.

_________________
My Zip build log...
http://www.vupilot.blogspot.com
http://picasaweb.google.com/vupilot/Chr ... O0x7SvsQE#

"Nothing screams poor craftsmanship like wrinkles in your duct tape."