Sportsman 180 Bilge Questions, Replace pump and transducer install

[Recoil Rob]

The bilge pump is the original from 2004 and I'd like to change it while on the trailer this spring. Any tips on how to do it, other than hiring an orangutan? Is removing the boat's engine necessary to be able to get my arm far enough in the holes?

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• Recoil Rob
• Jan 24, 2021

Also, I'm considering installing a thru hull transducer which gets glued to the inside of the hull. Can I cut a larger access port ahead of the motor well to get it away from all the stuff in the aft compartment? Is there enough support to do this in one of the two compartments marked?

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• Recoil Rob
• Jan 24, 2021

180 stringer layout drawing-2.jpg

• Recoil Rob
• Jan 24, 2021

Finally, what do I use to clean the bilge, get rid of all that black mold?


thanks,

Rob

 

[DennisG01]

There's worse things to do than to replace a pump for a "maintenance" reason, but I wouldn't rush to replace this. It can done on the trailer or in the water. If you can reach the pump with one hand, you can do it by feel. From those pictures, I have no idea if you can reach it or not, though. I'm not sure I undertand the part about "removing the engine"?

Thru-hull... so you're going to use it as a "shoot thru"? Will that transducer work for that? Make sure you find a solid glass area - if there's a cavity, it likely won't work correctly.

Hey, it's your boat - you can cut an access hole anywhere you want. Tip... go larger than you think - even a rectangular deck access hatch type, rather than round. Those cavities aren't filled with foam, are they? However, it looks like you may already have a nice spot where the pump's black hose is?

Do you have room to make your current access plate larger? Or a second one so someone else can help at the same time?

 

[wspitler]

As long as you find solid glass bottom, those shoot thru transducers can go almost anywhere. I put one in my Scout, right next to the bilge pump near the transom. I had better access than you seem to have, but it works fine. All they need is angle adjustment to match the deadrise and things close by in the bilge won't affect them. Thru hull fittings like scoops, etc. might cause turbulence if directly forward of the transducer location. I'd be hesitant to cut a hole in the deck as now you'll be concerned with structural stability around the perimeter of the new hole. Decks do have some structural purpose and cutting an access port can negatively impact that. It's a bigger job to do it correctly than it may initially seem.

 

[efx]

For an 18’ boat, I would invest in a high end transom mount 1 kw transducer from airmar. For the bilge pump, don’t remove the engine. Unscrew the hose clamp. Gently remove hose from pump barb. Unclip the pump from the base, don’t break the base arms. The hose will be sticky and non flexible and probably has cracks. Pull the bilge discharge thru hull with the hose if you cannot reach the hose at the thru hull. I put a new smooth white hose on the thru hull, thread the nut and route the hose to the pump barb. 5200 the thru hull and tighten nut. Clamp on hose to new pump and rewire pump. Make sure wires are same color to color. I’d get a new float switch also. For the mildew or mold, use Ajax in hot water. Scrub brush it with force and rinse. It may take a few passes.

 

[seasick]

I don't think that any Grady hulls below the water line are cored. I could be wrong but I kind of remember reading that somewhere. So in general a shoot through will work but not as well as a through hull assuming the same quality transducer. Even a transom mount type of transducer (downscan) can be used as a shoot through. Installation is critical for good performance

 

[DennisG01]

I don't think that any Grady hulls below the water line are cored.

I agree - and I should have been more specific. In his picture, the center of the boat appears to be perfectly flat - which to me, would mean a false floor and an air void between this false floor and the hull.

FYI... 5200 is the wrong stuff to use for a simple bilge pump thru-hull exit on the side of the hull. All that is needed here is a good quality sealant, not super glue that can only cause issues and damage to the boat if the thru-hull should need to be removed later on. Truth is, there are very few, if any applications for 5200 around a boat. The top cap to hull joint would be an area to use it, though.

Good 'ol fashioned bleach and water can do wonders after letting it sit for about 5-10 minutes. Rinse well. It won't cause any kind of damage to anything down there. Then any type of general cleaner and a brush will do the job.

 

[Recoil Rob]

There are two holes in the motor well above the bilge, both about 7-8" diameter. I asked about removing the engine because to get full extension of the arm down to the pump I'll probably have to lie down right where the engine is situated,

As for the shoot thru, the back end of a 180 is not flat but gently rounded, the shoot through can sit right on it. Solid glass too. I've had an Airmar transom mount on my last boat, properly installed, and got frustrated with it losing bottom at 25-30mph. Garmin recommended the shoot through and I like that design. Besides, I may still use a transom mount for a second, smaller B/U unit, they tell me it won't interfere with the shoot through.

 

[seasick]

There are two holes in the motor well above the bilge, both about 7-8" diameter. I asked about removing the engine because to get full extension of the arm down to the pump I'll probably have to lie down right where the engine is situated,

As for the shoot thru, the back end of a 180 is not falt but gently rounded, the shoot through can sit right on it. Solid glass too. I've had an Airmar transom mount on my last boat, properly installed, and got frustrated with it losing bottom at 25-30mph. Garmin recommended the shoot through and I like that design. Besides, I may still use a transom mount for a second, smaller B/U unit, they tell me it won't interfere with the shoot through.

Loosing bottom is usually due to a transducer set at the wrong angle relative to bottom or water turbulence. In the first case, the problem may not be 100% correctable depending on the difference in hull angle from displacing mode to planning mode. You have to optimize for one extreme. The transducer works best when it is parallel to the sea floor. That usually means that the transducer should be slightly tilted up at its end when the hull is at rest.
In the second case, turbulence, you may be able to improve it by simply lowering the transducer a bit. A 1/4 inch to start depending on it's current depth relative to the hull. If turbulence is caused by a hull fitting like a scoop or perhaps a chine or similar feature, the only way to correct the issue is to move the transducer out of the turbulent flow.

 

[DennisG01]

Loosing bottom is usually due to a transducer set at the wrong angle relative to bottom or water turbulence. In the first case, the problem may not be 100% correctable depending on the difference in hull angle from displacing mode to planning mode. You have to optimize for one extreme. The transducer works best when it is parallel to the sea floor. That usually means that the transducer should be slightly tilted up at its end when the hull is at rest.
In the second case, turbulence, you may be able to improve it by simply lowering the transducer a bit. A 1/4 inch to start depending on it's current depth relative to the hull. If turbulence is caused by a hull fitting like a scoop or perhaps a chine or similar feature, the only way to correct the issue is to move the transducer out of the turbulent flow.

Agree. A transom mount should work just fine. Even though you mentioned you thought it was, the last one you had probably just wasn't setup properly. That said, a shoot-thru (or even better, an actual thru-hull) is nice since there's no chance of damaging the ducer.