210 Maristar - huge hole in the sundeck?

[flyski]

So the PO of my Maristar 210 removed the linear actuator for the sundeck. While he was trailering it, the wind caught it and you can guess the damage that occurred - mostly to the honeycomb panel. I bought it knowing I would convert it at some point to a triple door setup so It doesn't really concern me - I can fix it.

I am starting the planning stage of the conversion and have been reading the available threads including the one by LaRue. What I have not seen addressed is why there is a hole cut in the honeycomb above the engine that is filled with a black abs plastic recessed box. There is plenty of clearance between the LTR Engine and the sundeck so I don't understand why MC would weaken the pad by taking this huge section out of the center? Is this a leftover work-around from an earlier model or different engine that needed the clearance?

Can any of you MC gurus help me understand. I'm contemplating leaving this "feature" ut of my new deck. What am I missing?

[flyski]

So far 75 reads and no comments - did I stump you guys?

[skydyvyr]

On my old X1, it didn’t look like there would be a clearance issue, but when I re-did my cover, I found that there wasn’t clearance for the RTP spark arrester without it. It may be that Mastercraft made one version of any style of cover that would work for all options available on the boat.

For example, an X1 with an MCX engine would not need the doghouse (spark arrester on the end of the intake, not the top of it) but I’ve seen them on those boats too.

—Sky

[mdskier]

I have no idea. But I did a triple door conversion on my boat last summer and did not retain that recessed plastic piece over the engine. No issues.

I think it was a remnant from the non EFI boats of that model. Carbs may need more head room.

[flyski]

I have no idea. But I did a triple door conversion on my boat last summer and did not retain that recessed plastic piece over the engine. No issues.

I think it was a remnant from the non EFI boats of that model. Carbs may need more head room.

That is what I was thinking - a vestigial structure. My engine has several inches of clearance.

Any pics of your triple conversion? any advice? Did you retain the honeycomb or use some other type of panel?

[FrankSchwab]

There were a number of engine options; it's likely that one of them (or one that they were considering offering but never did) needed an extra inch of clearance above the engine. And, as skydyvr said, they decided to only build one deck regardless of whether the clearance was necessary or not. Pretty normal for small manufacturing runs.

[robadele]

You are assuming the sun deck doesn't flex under load. That cut-out may appear to be un-needed when you just close the sundeck, but now go and stand on top of it while it is closed. Since the deck is supported only at the edges, I bet it flexes down some.

You also need to remember that this boat was probably designed before full CAD was in place for manufacturing and it was probably better to be safe vs. sorry for the clearance.

As another poster also said, they would only make 1 sundeck for all the engine options, so the LTR may not be the most difficult clearance.

[Ken]

Exactly what you speak of demonstrated in this picture from another thread. Also I remember another 205V from a few years ago that had problems with the flexing and it hit his distributor wires and wore through them I believe.

[CantRepeat]

Clearance Clarence!

https://www.youtube.com/watch?v=MQ9iPTu_FMA

[flyski]

You are assuming the sun deck doesn't flex under load. That cut-out may appear to be un-needed when you just close the sundeck, but now go and stand on top of it while it is closed. Since the deck is supported only at the edges, I bet it flexes down some.

You also need to remember that this boat was probably designed before full CAD was in place for manufacturing and it was probably better to be safe vs. sorry for the clearance.

As another poster also said, they would only make 1 sundeck for all the engine options, so the LTR may not be the most difficult clearance.

Thanks guys! I wasn't assuming anything but the clearance on my engine is several inches. I do see in the picture posted by Ken how little clearance some other engine options in other model boats have compared to mine so the vestigial structure/one size fits all explanation fits for sure.

Aluminum honeycomb is a fantastic material. My company builds aircraft with 1/2 inch honeycomb and it has incredible rigidity and strength. We hang a 400 pound engine off of it with only four small attach points. However, once it is compromised it does not rebound because to fail the face sheets either delaminate or tear- then the core is crushed. I used to take a piece of it to Oshkosh and offer $100 to the person who could bend it. Never lost my money. We use honeycomb because it does not flex yet is still very light. If that 1" honeycomb is flexing then it has structurally failed which I can only imagine would occur in a situation like mine where the lid blew open driving down the highway or is flexing *because* the hole compromised the whole (see what I did there :-)). Anyway Ken gave me the evidence I needed to replace mine without the hole and accompanying weakness. Thanks again!

[JimN]

Exactly what you speak of demonstrated in this picture from another thread. Also I remember another 205V from a few years ago that had problems with the flexing and it hit his distributor wires and wore through them I believe.

Spark plug wires? Look at the photo- it has an imprint from the flame arrester near the front of the plastic!

[Ken]

Jim, that's why I posted the picture, to show the interference between the flame arrestor and the lid. Spark plug wire reference was to Brucemac's post referencing coil wire and distributor cap from 2016. Did good to remember the thread much less that it had something to do with something that provides spark at my age.

[QUOTE=brucemac;1289093]

His issue was slightly different where in that his lid had worn just enough of a patch of the center coil wire that it was arching off up to his ski pylon. Mine simply slightly cracked the new disti cap coil pin right where it meets the disti cap plastic.

[gwozhog]

Mastercraft built some of the worst engine hatches in the world in the 90's and early 2000's. Rebuilt my 205v hatch out of 1/4" solid plate aluminum and now it could hold an elephant.

[CantRepeat]

[QUOTE=gwozhog;1569800]Mastercraft built some of the worst engine hatches in the world in the 90's and early 2000's. Rebuilt my 205v hatch out of 1/4" solid plate aluminum and now it could hold an elephant.[/QUOTE]

That's one way to ballast up a 205v for surfing!

[flyski]

[QUOTE=CantRepeat;1569805]

Mastercraft built some of the worst engine hatches in the world in the 90's and early 2000's. Rebuilt my 205v hatch out of 1/4" solid plate aluminum and now it could hold an elephant.[/QUOTE]

That's one way to ballast up a 205v for surfing!

I thought the same thing 😂