1985 Laser 18 LTV - Planing Problems

[Zuma]

Ever since first obtaining the boat i've had problems getting her up on plane. It's running a 1984 Evinrude V6 150HP with about 10" of setback and a nose cone. The motor trims waaaay down and under and I'd think it should tear out of the water...


But it doesn't.


I want to primarily use the boat for water skiing (and just toolin around) but it can't pull a skiier out of the water.

It's turning a 14.25"x24" SS three blade raker at 4200rpm @ WOT 52MPH on pitot-speedo on two diff boats (father's donzi classic 22' w/496HO calibrated)

I tried out a rebuild 14.25" x 21" aluminum to get 4600rpm @ WOT and lost a couple MPH. Still couldn't get me up

Finally bought a 14.25 x 19" 3blade AL and got up to 4860rpm @ WOT and lost a few more MPH (around 48MPH speedo now, prob getting 45). It's a huge struggle to get me out of the water... here's the kicker: I'm 5'10" and weigh 140 lbs.


Shouldn't this setup be able to tear my arms off getting up?

Compression and spark are good.

I took my little brother fishing and trolled for 20 minutes at 600RPM with the big SS prop. The little buzzer started beeping and i assumed it was overheating from the strain the large prop was putting on it with low water flow through the engine. Stopped the boat and my lil bro got a small bass on the line. We drove back home at 3000 rpm with no problems. I havn't heard the buzzer since. It's getting 25 PSI water pressure at WOT.

A week or so back I ran across lake Winnipesaukee through some really rough water and it started to die and lost a lot of power, couldn't get over 3500 RPM. The rough water had losened muck or something in the fuel tank and gooped up the fuel strainer and carbs. Carbs were cleaned/parts replaced etc. Back to the above numbers at this point.

What do I need to do to turn this into a good ski boat?
Any prop suggestions?
Would a four-blade or a hydrofoil solve my problems?
Doesn't it seem like the motor isn't putting out what it should? I mean only 50mph?

Top speeds were with only myself in the boat and around 10gal gas in the stern. Skiing was with my dad in the drivers seat (170lbs) and an observer (100lbs) also up front.

Thanks for the help!

[Zuma]

http://www.starsistar.net/user_files/justin/zuma2Smaller.JPG


http://www.starsistar.net/user_files/justin/ZumaSmaller.JPG

[STV Tunnel]

First, way too much setback. The motor right on the transom or with a short jack plate is all the designer ever recomended.

Second, something is wrong. That boat should stand straight up, drop and settle in and be on plane and gone like a shot. It should plane at 30 mph or so. Add a hydrofoil and it should plane even slower. You should be able to launch at neutral or + trim.

It is either waterlogged, the bottom is messed up, or something peculiar.

I'd be interested to see what is actually wrong. The cores on those boats get water logged and they wind up weighing a ton. Might want to start there.

[ChrisXS2003]

How high is the propshaft relative to the pad? Sounds like you're too high.

[Zuma]

OK so i was way off on the setback... its more like 6 inches. You can see from pic below. The glass on the bottom doesn't look deformed or warped. I would guess water logged... the rear bench seat was rotted wood, the front bucket seat foam is like a wet sponge, and under the rear port seat feels like rot too... slightly raised and soft under the surface glass. makes me think it was sitting out uncovered full of water. mehhhh.

So heres the question of the hour: How can i tell if it is water logged and what can i do about it?

It is planing around 30mph but it takes forever to get there, and more (sometimes never) with a slolum skier. If you have nutral/+ trim it cavitates trying to plane. I'm not sure how high the motor is sitting fromt eh pad, but the manual jack plate is at "0".

http://i16.ebayimg.com/01/i/04/0c/78/e5_1_b.JPG

[big D]

From the pic it looks like the motor is too low.The prop may be bogging down comming onto a plane.If you change the hights you probaly won't be able to run the aluminum[sp] props,but the RPM's will come up also,just a thought.Good luck,Dennis

[Zuma]

the picture doesn't really let you know the height of the motor well enough... i'll measure the height of the prop shaft from the pad this weekend and let you know. Anyone have any advice on dealing with a water logged core?>

[Flashypaint]

I had a LTV year before last and was running a 150 Merc. Sounds like you have water in your foam . Theres a few things you can do without cutting the boat apart to remove the wet foam . email me and i can send you some pics and show you what i did. I removed 6 trash cans and 200lbs of foam using a drill and a shopvac.

Flashy

[Flashypaint]

By the way thats a sharp looking Laser......

[chynewalkr]

i use a dehumidifier under the cover(tightly fitted) of my boat after it takes on water, sometimes i get 2 or 3 gallons out of it. you could probably get some out doing that. ive heard of the shop vac method and it sound like that works even better

[Ted Stryker]

Looks like an 8" set-back... Anyway, my brother has owned a couple of those boats and they should plane off no matter what unless the boat has alot of water in it's core.... The two that we have cut apart were completely saturated... One of the best sub 95 mph hulls around in my opinion... They come out of the whole almost instantly and air out real quick for great acceleration with very little trim...

[76baja18ft]

post the question over on the byuboyz board.. ask for TREX.. he has one and is a laser guru.. www.byuboyz.com

[STV Tunnel]

These hulls like cupped overhub choppers. A skier should make just a little bit or difference if you have a decent prop. Sounds like your prop is digging a hole. Are these all reworked hack job props?

My LTV will run over 102 MPH with a lightly modified 175 Merc with 1 person and a light fuel load. It will run high 80's - low 90's with 2 250 lb people and a full fuel load - both these speeds are with ideal water, wind, temp and barometric pressure conditions.
It will 0-60 in silly times...so low I ain't even gonna post them here under the same conditions.

2 1/2 inches of setback, propshaft even with pad, 28 Mazco RE3, will launch at any trim setting. 0-60 the same if launched with full + trim, or neutral then bump up trim.

I know mine gets heavy too when its wet but I have never seen the problems you are talkin about even with a hole diggin cleaver on it. It will tow a boat so I know it will pull a skier up.

Whatever it is I want to know what's wrong.

[T-REX]

I'm not knock'in ya power, but it soundz like it's kinna on tha low side on the low end...Your LTV should still git up even with a load ov water...I would be will'in to bet it's saturated, and the only cure iz to pop the top, and cut out the floor, and dig out the wet foam...I have had to do it many, many times, on both the Vee's and the LTV's...To me, it's a down fall ov the builder, because the do not seel the lower knees and transom, and the holes the drill from one side to the other(Thru stringers) are left exposed...

Dump the Jack plate, put the leest U kan put, and the only reason U would need any at all, iz for the vertikle adjustment ov the motor...The torque ov that motor, a good wheel, and a dry hull should pull a skier's arms outta socket!!!...If your bow raises over 3"s when jump'in on plane, U have water, trimmed too high, or low on power!!!...My LTV would actually jump on plane from nuetral trim, and be runn'in in juss a few feet...The don't make ANY boat that will plane, set, and run any faster than the LTV!!!!...If U juss ride wit passengers, and pull ski's, find U a 4 blade "Shooter" prop, and U will thank U had a 300hp mota back there, and it still runs good on top!!!....

Bad newz on this subject tho, U KAN'T GIT THA WATER OUT WITOUT REMOVEN THE FLOOR, AND DIGG'IN OUT THA SATURATED FOAM!!!....REX

[Zuma]

Bummer! how long would that take? I'm going away to school in september.... could do it over winter break (3 or so weeks). maybe some of you could give me some help on the procedure for taking the top off and digging it out.

Cost estimates on putting it back together when i'm done?

[T-REX]

It'z not fun, but not that bad either...

Take the rubber out ov the rub rail...U will see sum screws, unscrew the rubrail(it will probablly be stuck with silicone around the back...The once the rail iz off, ther will be sum more screws holding the top to the hull, remove them...Now, de-rig the boat(remove all the wires and steering from motor, and remove motor...all the wires will be attached to the top(cap), so juss lift it off...U will need a couple helpers...not that heavy, but awkward...I hung mine to the rafters ov my shed, but U kan lay it on saw horses or sumpth'in...DON'T STAND IT ON IT'S SIDE!!....Once the cap is off, remove what ever iz left in the hull(seets, tank, etc)...U will see wher the floor ends on the sides...about 8"s from the edge, set your Sawblade to cut 1" deep...then cut out the floor...the remaining 8"s of floor can be removed wit a chizel, or if ya lucky, by juss pull'in up on the remainder,...once the floor iz out, dig out all the saturated foam, and make sure your stringers, and knees are still solid(they usually are, but the tops ov the stringers will git soft)...Take a 1/8th" drill bit and drill sum holes in the lower Transom, and make sure there iz no wet wood in it, kuz if it iz, now iz the time to put a new transom in......

Now, I replaced my foam in my big rex with the white foam that U buy in blocks, like the float house boats with, or piplines...I cut it to the shape I wanted to fit snug, then painted the pieces with latex paint...Fuel will melt the white foam, but the latex won't melt the foam, and when dry, fuel won't hurt the latex...the white foam WIL NOT SOAK UP WATER!!!...The tighter U pack it, the better it works, because it gives solidity to the hull, but don't make it too rigid...U have to drill sum holes in the stringers(and seel them wit rosin) to let out water(condensation from sun and cool water)...Even if U totally seel it, it will git water from that condensation...Before U replace floor, I paint tha bottom of the plywood used for the floor, with rosin so it will not take on water from condensation...then U kan use the desired mat U want to do what U want...(the heavier the better for a river boat, IMO)...Then pop tha top back on(the top never fits the hull reel good in the back, and the bow, so seel wit a good silicone before aU put on the rubrail...Now, If U want a SOLID boat, glass the inside al the way around wher the top joins the hull(make'in a one piece hull/cap...But, this will add a lil weight, and make it dificult to take apart if sumpth'in kums up later...I'm not a fiberglass guru, but I have dun quite a few, so that prooves it ain't rocket science...Juss git wit sumone that knows how to mix the rosin...thats the key to plenty work time, but sets up good and hard...good luck...REX

[150aintenuff]

first key to show the boat was way heavy was the fact that you couldnt get more than 4800 RPM with a 19 P prop... that engine should be runnin at 6K... OR make sure the engine is running on all 6...

[Zuma]

Doesn't sound too bad... not at all.
I've had the engine checked out... The wood in the back of the boat is
wet and fullo water (the floor), so soakd foam has gotta be the problem.

maybe before i do the work i should weigh the boat at a weigh station. what shuold this thing weigh? (i'll subtract car and trailer empty)

thanks 'gain

[150aintenuff]

I have had engines runnin on 5 cyl sound perfect but just lacked RPM on top... I am not arguing the fact that the foam may be wet just lookin in another direction that could also explain your situation. because your rpm is WAY LOW and that in turn could cause the motor to go POP.

[wideglide55]

I agree,I had my 235 rebuilt broke it in easy and on about the fourth boat trip opened the throttle all the way,4700rpm with a 29SRX.Pulled the spark plug boots thinking I had a fouled plug,5 of them looked great inside one was completely rusted,changed the plug wire, instant 6000 rpm. You could also have one bad coil causing your low rpm.

[David]

I bet the motor is sick.

When I got my old Virage/XR4 it would run low 60's with the engine flat on the transom. It would go mid 50s full of people and pop my 170 lb out of the water.

The Laser should be a faster boat than the Virage. Just how much water could be in it?

[STV Tunnel]

A heavy pleasure layup weighs like 700 lbs range and a light race one weighs like 500 lbs I think. Wet foam can add the weight of passengers.

You were sayin your motor was fine so I assumed soggy boat and bad prop.

If your motor is indeed ok than what else is there besides heavy boat, prop and setup. Make sure the engine is really ok. Maybe try a test wheel with the boat on the trailer backed in at the ramp and check for revs.

You have to assume the reason the boat sold so cheap on ebay someone may have been trying to pass on a problem.

[David]

My Virage was 950 lb, so it was a heavier boat 'dry'. Add 4 people and it is a lot of weight. I got more speed with 4 people than he has empty. More or less the same power, 150.

His motor must be sick.

[Zuma]

Yeah... I don't think weight alone could be causing my loss of RPMs.... I've tried a few props.. didn't get up to the lake this weekend so couldn't make any progress. I'm gonna try to get up there next weekend and I'll get my dad to run it over to a omc service place.... have them check it for real this time...



God, I would love to find 1200 RPMS in a bad plug wire or coil.