New to boating and to pontoons... Questions

[dlang123]

So how low in the water should the rear of the pontoon sit? My wife and a friend commented that mine (first time we had it in the water yesterday) seemed to sit a bit low. I did the slosh test, and shook it side to side, all I could hear was the gas sloshing around in the center tank under the deck. 2007 SunTracker 18ft with 40Hp 4 stroke Mercury outboard. Bought it used, had been a rental. I'll try to get a picture up of the water line on the tubes.

2nd Question. I guess I had it trimmed to far down, and it was throwing water up onto the back deck at full speed. Is this normal? I trimmed it up some, and it seemed to be slower, but no water getting thrown..

3rd Question. We rode it out at full speed a bit, and turned it around, had no problems with it for a while. Once I let it idle a bit and turned it around, I could only run it about about 30,000 rpms or it would flutter and stutter if I tried to go any faster, full speed, to almost nothing... I ended up shifting it into neutral, and over revving the engine until it cut out. Then after starting it back up, it was fine all the way in. Any ideas what could of caused this?

4th Question. This may be related to the 3rd, but I guess I need to open the vent on the tank while out? The tank is a 30 gallon built in tank under the middle rear of that pontoon, the only vent I really see is in the gas cap at the rear. I thought to myself, well I don't want water getting in, so I closed it up. Somewhere around the same time we were idling for a bit and I was about to over rev it.. I think I checked the vent, worried maybe water got into the fuel, and that was causing the stuttering, so I stuck my arm down and tried it, but then tightened it back up.. Not sure if it was open at the time or not. Just read today that your suppose to open the vents on boats... I was unaware of that. (Newb).

I spent a bit of time on the forum looking for these answers, and either I missed them, or they weren't clear enough to me. Sorry if they are repeats.

 

[BatDaddy1887]

4 Stroke engines are heavy beasts and tend to weigh down the back a bit more than 2 strokes. The water line on the tubes should be some indication of normalcy. If your tubes don't already have drain plugs on the very back of the tubes, consider hiring someone to drill and tap holes for brass plugs....and use plumbers tape on the threads.

As for water splash in the back, try looking back there while at WOT. You may find that the engine sits too low or there is some other obstruction causing the splash.

....you may mean 3,000 RPMs. Sounds to me like a small bit of blockage in the carburetor jets. To possibly prevent this in the future, you may want to add Seafoam to every other tankful to help keep that system clean and free of debris.

Your gas tank should always have some sort of ventilation. It is not a good idea to close off the vent system while under way. Most built-in tanks have separate hose coming from the tank as a vent, permanently attached to the exterior of the boat. Boats that run their gas with removable gas tanks mostly have the vent built into the cap.

 

[crb478]

Most pontoons have about 1/2 of the rear toon under water, less in the front. If you want to install drain plugs it is easy to have done, but use a good aluminum welder and aluminum plugs, dissimilar metals will give you problems. The motor may have been trimmed to much or it may be set to high or to low. Proper motor set up can go a long way in how well it performs. 3&4 may be connected. If the gas was not vented it could not get to the motor in the required quantity and would have eventually cut off totally. If you opened the vent it allowed air in and allowed gas to flow freely to the motor.

 

[BigDfromTN]

My first thought is that 3 & 4 are related. The vent must be open for it to run right very long.
I had left mine shut once and even towed a friend back to the ramp. Then headed back to our camp and boat went dead in middle of river. Looked back and noticed the bulb was sucked flat. Opened the vent and give her a few squeezes and away we go!

Leave the vent open.

 

[Old Screwball]

ALWAYS open the vent on the gas tank. Eventually the engine will run like it is gas starved. SunTracker doesn't use any other vents than the one in the gas cap. About log buoyancy. Look any add for Tracker boats, the 'logs are submerged about 1/2 way while sitting still in the water. About the drain plugs, don't bother, Tracker logs are segmented. You basically have 3 separate, sealed chambers on each pontoon. A drain plug in the end unit will only drain that chamber. Look on top of the logs, you will see 3 separate access plugs with plastic caps. I guess you could insert a skinny plastic 'straw' in there and suck out any water, but the likelihood there is much water in there is pretty low, UNLESS you hit a rock or something. Enjoy that Tracker, they are good boats!

 

[dlang123]

Thanks guys, I had a chance to take it out again this weekend, I think the depth of the logs is fine. The rear is about 1/2 submerged, right on the water line on the tubes, so no real issue there. Slosh test comes up clean, I do have a crease in a tube where the previous owners apparently hit something, just going to leave it alone. This time I made sure to open the vent before we put it in, no issues at all on the motor. Even pulled a tube about as well as can be expected with a 40HP, about 14mph.

However the outboard still threw enough water back up on the back of the deck to wet a foot or so of the carpet under the walls, may just need to work on trim, or need to move the motor, will have to look into it some more. I was the only licensed boat driver so didn't really get to take a look and try to get it adjusted just right.

Another question though:
I'm guessing that I need to adjust the throttle cable, but it seems like there is a ton of room after shifting into forward before it really engages any throttle, and then between slight throttle and full there really isn't much room on the lever. Full is about 6000RPM. I have to move it super slow to get any real variance between them. Does this sound normal? I would expect (with 0 experience on it, I need to drive a friends boat see if it is similar) that after shifting into forward, that shortly after there should be a steady ramp up of speed without me having to up the throttle so much before it kicks in. Maybe it is just my newbness.

Question 2:
I also managed to damage what I believe are the splash fins/guides on the front of the pontoon when trying to trailer it (these boats are big!), I listened to someone about being off (the guides would of corrected it) but the edge of the splash fin on the front got caught when I tried to back it up and bent off some... I was able to bend it mostly back later, but I'm guessing I should get someone to weld it back? I might be able to drill a hole in the end and attach it back to the aluminum that way from the way they look, I will try to get a pic of it. Thoughts?

 

[Old Screwball]

Those "Splash Fins" are called lifting strakes. They help the 'toon plane in the water. Very Important. Might be a good idea to have them checked for angle and weld. Good Luck

 

[ahicks]

Lifting strakes are generally below water level - to allow them something to push on to generate lift. Splash fins are rarely underwater - unless you've managed to turn the front of the boat into a submarine?

Splash fins can/do take a beating while loading/dockiing. Not unusual for older boats to have one or more missing. Welders are used to seeing them bent or missing, can fix you right up.

 

[WaterDR]

I don't think it's that unusual to get some splash lime that especially with a smaller motor on a bigger boat. You are probably not going fast enough for the splash to just hot the water so to speak. Some toon designs are more subject to having this too I think.

 

[dlang123]

So.. had a bit of trouble with it running.. took to the shop..
Turns out my tank has about half water in it.. its a 30gallon built in... can't buy anymore.. custom fab part -400 just part. While they were looking at that, they mentioned that the Motor Pod is looking a bit weak these days too, 600 custom fab, just part....

Offered to put me an external 15gallon tank on for 170... Also found out it was pretty under propped.. has over rpming a lot.

Changing propeller and oil in everything will run me about 600 bucks. But then I still have the bad motor pod and fuel tank to deal with...

Any suggestions on those? Does anyone think that the cap vent could let in that much water with all the splash I had on the back?

Maybe just pull it out of the shop.. and try to drain the tank, let it dry out.. then partial fill it and take it out? Still actually running on mostly the same tank of gas as when I purchased....

 

[steelespike]

Are you the least bit mechanically inclined?
Your 40 will use about 4 gallons per hour at wot Probably about 1 gph at 6 or 8 mph.
I would think 2, 6 gallon tanks would last a long time just cruising.
Drain the 30 gallon and leave it for now.
What size prop is on there now?Numbers are under the prop nut.
Is the rpm from an onboard tach?
I would check it against a shop tach.
If your having trouble with the motor pod with only a 40 hp I would be talking to Tracker boats.
Get a second opinion on the motor pod.
Look it over yourself. Any cracks ,bolts pulling through, excessive corrosion.
Grab the motor and shake the heck out of it as thrust forward and reverse might do.
Any transom movement?

 

[BigDfromTN]

Im with Steelespike.

Bring your boat home and get a second opinion. Just cause tank has water does not mean it needs replaced. Worst to me would be a redesign of tank cap with a cover or something to avoid the splashing of water. Check that engine splash and you may kill 2 birds with one stone.

Best of luck!

 

[ahicks]

Another test to check the transom - with the boat out of the water, engine down in the run position, just step on the prop hub. If you don't see much movement, you're good to go. If you see a lot of movement, where is it coming from? Some movement of the engine on it's mounts is normal - to isolate vibration.

Agree on the 6 gallon gas tank idea - AND - finding somebody else to talk to about any required repairs. Unless there's a misunderstanding somewhere, that sounds like a bunch of crazy talk. Just like what you might hear from somebody looking to take advantage of an unsuspecting boater.