2000 SAN lacks power when ballast are full

[erikj]

Hey guys and gals,

I am new to the ballast world but I was curious if I should have major power loss when my ballast are full to the extent of only being able to go about 12-13 mph (whether we have 2 or 6 people). We are surfing so it hasn't been a huge deal but seems like it would be impossible to wakeboard with the power loss at this point. Oh and it runs perfectly normally without the weight, planes out fine, runs about 35ish mph. oh and I have noticed that I might have some leak somewhere because the boat is taking on a little water as well, doesn't seem to be a ton though.

Some of the details:
GT-40 5.8L Motor without an hour meter, no clue how many are on it, it does have the original interior that is in really good shape though if that is any indication
Ballast: stock tanks with two 350lbs on top, 540lb in the ski locker
Suction Gate deal that I made.
Tune Up: I have only changed the fluids and done the impeller before taking it out this year, maybe needs new plugs? Distributor?

Thanks in advance

[nukemustang]

What prop do you have on it? That seems like a lot of weight, quick math, about a ton of water and whatever people, gear, etc. are in the boat.


Sent from my iPhone using PLT Nautique

[erikj]

Yeah I guess it is a lot of weight but I assume people are actually running a lot more since I have the crappy stock tanks as well. To be honest I don't know what prop it is, looks like I might have to loosen the nut to find out but pics are attached. nukemustang

[a.klos]

Empty boat should be capable of 45ish with stock 4 blade Acme 380, I know, I have it. Higher torque props like Acme 1578 should be able to ride with that weight at ease. Guesing from pics, yours is Acme 380 or 644. But even 644 should be able to handle that weight. Your prop should have a stamped numbers from other side of which model.

[erikj]

Yeah a.klos I have only had the boat in the water a few times so not positive on top speed but it is pretty fast, also a pretty unreliable speedo. I'll see if I can find that model number. doesn't sound good not being able to push that weight easily. Wonder if a tune up will help or if I am missing something, do you think it might have something to do with the wake gate?

[nukemustang]

You phone can be an easy GPS device to check the speedos.

I also just noticed that you are in UT.... so your lake is at what 6-7000' of elevation? so if this is true: HP Loss = (elevation x 0.03 x horsepower @ sea level)/1000 then you could be wayyyyyyy down on power that most people have at sea level, plus all the extra ballast, plus lack of a "'pulling prop" may all be a bad combo. Now, for the tune up, if you have never done one, maybe cap/rotor/plugs might be a cheap place to start to see if you get any improvement.

[erikj]

Thanks nukemustang I actually have a speedo app so next time Im out Ill try and get a true speed. Very good point on elevation and yeah the lake is about 6500 feet. Yeah the tune up wont hurt so Ill start there. What prop should i have, the 1578? Thx again

Sent from my SM-G950U using PLT Nautique mobile app

[erikj]

Oh BTW this boat sat for 2+ years and I have no idea if the gas had stabil or anything so could it possibly be a fuel issue and should I replace the fuel filter in the FCC?

[charlesml3]

Oh BTW this boat sat for 2+ years and I have no idea if the gas had stabil or anything so could it possibly be a fuel issue and should I replace the fuel filter in the FCC?

Honestly I think there are just too many variables here for us to help you sort this out with forum posts. You have old fuel, unknown maintenance status, possible over-prop situation, possible high-elevation, and a relative newcomer to these kinds of boats (you).

I'd recommend asking around your area for a qualified mechanic and someone who really knows these boats. Have them go through it. It may need a tune up, or fuel filters, or all of the above. The fuel may be in terrible condition. Someone could have re-propped the boat for a different use. You need to address each of these potential issues methodically and narrow the problem. Shot-gunning parts at it is not a great way to figure out what's wrong.

-Charles

[erikj]

Well I do all my work on my boat so I would rather save the money and do it myself, especially if I can get the spark plugs, plug wires and fuel filter for $120 which for sure needs to be done no matter which way you look at it. Also, aren't the forums for this exact reason to let people chime in with their experiences so that it can give me some options before spending a ton of money with a boat mechanic? It might be easier for you to go to a mechanic but is not that easy for me, this is by far the most expensive toy I have ever had and would like to know more about it (especially working on it since I have grown up working on everything I have owned) so I would hope for a little better feedback then take it to a mechanic. charlesml3

[NautiqueJeff]

If that's a stock prop, at that weight, that elevation is killing you. Get a different prop.

[erikj]

If that's a stock prop, at that weight, that elevation is killing you. Get a different prop.

So what would yoi suggest for a prop Jeff? Hiw are the OJ props, seem to be a little less expensive.

Sent from my SM-G950U using PLT Nautique mobile app

[charlesml3]

Also, aren't the forums for this exact reason to let people chime in with their experiences so that it can give me some options before spending a ton of money with a boat mechanic?

Of course they are. Please go back and read what I wrote without getting immediately on the defensive. We're ALL trying to help you here. The problem is the huge number of variables in the equation. We don't know if the fuel is bad. Or if it needs a tuneup. Or if the fuel filter is clogged. Or if it needs a different prop.

You're interested in saving money but what if you go with "it must be the prop" and that's not it? A prop is easily over $500. Nobody wants to see you drop $500 on a prop only to find out it's actually a bad distributor cap. Or a bad tank of fuel. I'm concerned that you're already looking to start applying fixes without really knowing what the problem is.

-Charles

[Blamey]

I think getting the numbers off the prop and getting your top speed (and RPM) would be a good starting point. These both cost nothing and we can see if the boat is under powered or just under propped or both.

Let's do this before changing the gas/filter and doing the tune up. Then you have a base line to see if anything changes.

What elevation are you at?

Edit: Numbers for the prop are under the prop nut. I can't make them out in the pic you posted.

[seth]

That is not the stock prop, looks to be an Acme. 6500' is your biggest problem and nothing is fixing that. I used to have an 01 SAN that I would take to a lake at 4500' with an ACME 1236 which was the most aggressive prop they made at the time and I would have to take out a bunch of weight to get it to plane. Granted, I was running 3000lbs of ballast, but the elevation made a huge difference. I probably had to take out at least 1000lbs to get on plane.

First thing, loosen the prop nut so you can see what prop you have and let us know. At 6500' you want the most aggressive low end prop you can get. Also try putting the 540lb sack in the bow instead of ski locker to help it plane.