I took my '98 PL 251 and converted it from an I/O to a bracketed OB. There was some project creep and some other modifications along the way. I am very happy with the end result
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A bit of history...... I took delivery in January 1998. I ordered it with a 7.4 Gi Volvo Penta duo-prop. Engine and outdrive were replaced with a 5.7 Gxi in 2003. About 2007, I had an aftermarket hardtop installed. The boat has over 3800 hours of running time.
Last year, I began the renovation. I decided to do this because this boat fits my needs almost perfectly! Easy to take it out alone but fishes 3-4 guys well. Economical, great range, fish boxes, great storage, trailerable, overnighter package with stove and macerated head.
Over the years and with the availability of more powerful and reliable outboards, this make over was more and more on my wish list. I only had a very basic working experience with fiberglass. I decided to take this on......I did ALL the work myself with the exception of removing the old block and hanging the new Suzuki.
I found a buyer for my VP power package! He took a test drive and gave me a deposit. The removal began.
The bilge was a mess! I used degreasers, Simple Green, and lots of elbow grease. Then came the sanding and grinding dressed in full Tyvex suit, gloves, goggles and respirator. To say this work was absolutely awful is an understatement!
The aft end of these stringers were hollow to allow for through bolting the motor brackets. I also discovered that the hollow stringers were full of water! I believe water had simply leaked in from the top cut-outs at the top of each stringer past screwed on and un-sealed covers. Once dried out, I poured in 4# expanding foam, glassed the stringers, reinforced the stringer/transom/ hull joints, and gel coated the bilge areas I could reach.
The transom cut for the outdrive showed no signs of delamination or moisture intrusion. Of course, with Divinycell core, it can't rot either.
This no-wood construction was a main reason I bought a Pro-Line in the first place.
I thought long and hard about closing up the transom hole. I knew my bracket would span this area and not put direct contact on it. The cut was pretty irregular and I didn't think enlarging it to mate to a more regular shaped plug was a good idea; removing more transom could weaken it. So, I poured in expanding foam, sandwiched by 2 pieces of parchment paper lined plywood. Worked perfectly! Fiberglassed over it both inside and out.
Turned my attention to the transom. It was warped and curved in a couple of ways. The top of the cutout (at the top of the outdrive) had a bit of a nose to it; like the weight of the drive had pulled the transom out and aft a bit. The back edge, from port to starboard was concaved in about 1/2 inch overall.
I had been working with Stainless Marine on building a single engine bracket for me. I wanted it full width so this curvature in the transom was a problem. I also wanted more flotation than their standard bracket because I planned to add a larger bait tank (more on this later).
It took a lot of sanding to get the transom flat. Then I added layers of glass, core-cell, and thickened resin to build out the transom where the bracket would be bolted.
I made a template for drilling the 20 bolt holes. My friend and I did a dry fit. The next day and 2 tubes of 5200 later, the bracket was in place!
One of the other improvements was to the helm. I removed it to do some filling and repairs. Re-painted the top of the helm areas. Cleaned 19 years of crud from the sliding cabin door since the tracks were finally accessable.
I found some switch panels on Ebay. Re-used and added to the original Carling switches and bought new rocker covers for them. I flush mounted all new Raymarine electronics. Always wanted an autopilot, but the I/O installation was too expensive. I have one now.
Some before and after photos:
Another desire was for a larger installed bait tank. I searched online for one that would fit inside the transom area. Couldn't find one....decided to try and build my own. A ton of work but it works great! Again, never done anything like this before.
I designed the tank to be contained within the transom cap. I cut out the transom sink and re-used the existing lid and moulded lip for the new bait tank. The tank I bonded to the underside of the cap using high strength polyurethane construction adhesive. After a few days set, I stood on one exposed edge of the tank. It is not about to come detached. It is between 20 and 25 gallons filled.
I added a Coosa/fiberglass cap where the old bait tank had been. This surface later covered with a Starboard cutting station.
The new bait tank meant I needed to relocate the 2 batteries. I built a Coosa/fiberglass battery tray to span the stringers. I changed the electrical system to a dual circuit design; an engine and a house/electrics. I bought a battery switch cover and installed it at the transom tuna door. No more reaching in to switch on the battery from my knees (as you get older, most of you can appreciate this!).
I added a Blue Seas fuse panel to eliminate most individual fuse holders. This also added more ground points. I eliminated all remote switches so all pumps and lights are helm controlled.
Lots of additional tasks: Suzuki harness to the helm. Pull steering hoses. Wire runs for hull LED, auto-pilot pump, and wash down pump. Re-purposed I/O blower circuit for bait tank LED. Rigged new DF300AP. Added new connectors to all existing circuits and spliced and cut as required. Relocated battery charger, bilge and wash down pumps. Ran new fuel line and installed new filter assembly.
With the engine mounted and the electrical system sorted, I had to do more fiberglass repairs. Removing the I/O blower system left 2 cutouts on either side of the hull. These were pretty easy to glass and fill and gelcoat. I ordered from Spectrum (iboats.com) since they have a matched gel coat color for my '98 Pro-Line. I have to say it was a pretty good match for a 20 year old boat. I can see it because I know where to look.....
Using 20# Coosa, I glued in some pieces to form the aft corner of the engine cut out. I glassed and filled and rolled on a few layers of gelcoat using a fine foam roller (learning some tricks along the way). This resulted in a pretty good finish! Not mold-like but pretty smooth anyway. Didn't I say this is a 20 year old boat.
I made a hatch cover and rolled on some Kiwi Grip to match my existing sole of the cockpit. I enlarged the vertical cut out slightly for better access. I had a custom cover made from boatoutfitters.com. They also did the cleaning station for me.
This last picture shows the finished cockpit and transom. It is so roomy and more fishable. No more jumping over the doghouse of the I/O. Easier to open the fish boxes. Remove the hatch cover and I have excellent access to the batteries, pumps, filter, and components.
OK, so many of you must be wondering about handling and performance.
I swapped a 320 hp VP for 300 hp Suzuki. Once upon a time, this hull was available as either an I/O or a bracketed OB. Stainless Marine was the OEM supplier at that time. During my conversations and due diligence, I was very reassured that this hull was a great candidate for this conversion....
The Suzuki is much more quiet across the entire RPM range. I traded away about 400 pounds but the engine sits farther aft. The boat's stern floats about 2 inches higher than before. In the first photo of this thread, you can see the old scum line for comparison. When drift fishing, I don't get water sloshing in under the transom door like I did before; maybe it is because the stern is a bit higher or maybe it's due to the full width bracket. The bow rise coming onto plane is very slight. With full tabs and trim, I can plane at about 15 knots.
The two best propellers I have tried thus far are the Suzuki 3 blade in 18.5 pitch and a Powertech OFX 4 blade in 19 pitch. I am getting anywhere from 2.2 to 2.6 mpg at 30 mph depending on fuel load with a full curtain package using the PT prop.
A bit of history...... I took delivery in January 1998. I ordered it with a 7.4 Gi Volvo Penta duo-prop. Engine and outdrive were replaced with a 5.7 Gxi in 2003. About 2007, I had an aftermarket hardtop installed. The boat has over 3800 hours of running time.
Last year, I began the renovation. I decided to do this because this boat fits my needs almost perfectly! Easy to take it out alone but fishes 3-4 guys well. Economical, great range, fish boxes, great storage, trailerable, overnighter package with stove and macerated head.
Over the years and with the availability of more powerful and reliable outboards, this make over was more and more on my wish list. I only had a very basic working experience with fiberglass. I decided to take this on......I did ALL the work myself with the exception of removing the old block and hanging the new Suzuki.
I found a buyer for my VP power package! He took a test drive and gave me a deposit. The removal began.
The bilge was a mess! I used degreasers, Simple Green, and lots of elbow grease. Then came the sanding and grinding dressed in full Tyvex suit, gloves, goggles and respirator. To say this work was absolutely awful is an understatement!
The aft end of these stringers were hollow to allow for through bolting the motor brackets. I also discovered that the hollow stringers were full of water! I believe water had simply leaked in from the top cut-outs at the top of each stringer past screwed on and un-sealed covers. Once dried out, I poured in 4# expanding foam, glassed the stringers, reinforced the stringer/transom/ hull joints, and gel coated the bilge areas I could reach.
The transom cut for the outdrive showed no signs of delamination or moisture intrusion. Of course, with Divinycell core, it can't rot either.
I thought long and hard about closing up the transom hole. I knew my bracket would span this area and not put direct contact on it. The cut was pretty irregular and I didn't think enlarging it to mate to a more regular shaped plug was a good idea; removing more transom could weaken it. So, I poured in expanding foam, sandwiched by 2 pieces of parchment paper lined plywood. Worked perfectly! Fiberglassed over it both inside and out.
Turned my attention to the transom. It was warped and curved in a couple of ways. The top of the cutout (at the top of the outdrive) had a bit of a nose to it; like the weight of the drive had pulled the transom out and aft a bit. The back edge, from port to starboard was concaved in about 1/2 inch overall.
I had been working with Stainless Marine on building a single engine bracket for me. I wanted it full width so this curvature in the transom was a problem. I also wanted more flotation than their standard bracket because I planned to add a larger bait tank (more on this later).
It took a lot of sanding to get the transom flat. Then I added layers of glass, core-cell, and thickened resin to build out the transom where the bracket would be bolted.
I made a template for drilling the 20 bolt holes. My friend and I did a dry fit. The next day and 2 tubes of 5200 later, the bracket was in place!
One of the other improvements was to the helm. I removed it to do some filling and repairs. Re-painted the top of the helm areas. Cleaned 19 years of crud from the sliding cabin door since the tracks were finally accessable.
I found some switch panels on Ebay. Re-used and added to the original Carling switches and bought new rocker covers for them. I flush mounted all new Raymarine electronics. Always wanted an autopilot, but the I/O installation was too expensive. I have one now.
Some before and after photos:
Another desire was for a larger installed bait tank. I searched online for one that would fit inside the transom area. Couldn't find one....decided to try and build my own. A ton of work but it works great! Again, never done anything like this before.
I designed the tank to be contained within the transom cap. I cut out the transom sink and re-used the existing lid and moulded lip for the new bait tank. The tank I bonded to the underside of the cap using high strength polyurethane construction adhesive. After a few days set, I stood on one exposed edge of the tank. It is not about to come detached. It is between 20 and 25 gallons filled.
I added a Coosa/fiberglass cap where the old bait tank had been. This surface later covered with a Starboard cutting station.
The new bait tank meant I needed to relocate the 2 batteries. I built a Coosa/fiberglass battery tray to span the stringers. I changed the electrical system to a dual circuit design; an engine and a house/electrics. I bought a battery switch cover and installed it at the transom tuna door. No more reaching in to switch on the battery from my knees (as you get older, most of you can appreciate this!).
I added a Blue Seas fuse panel to eliminate most individual fuse holders. This also added more ground points. I eliminated all remote switches so all pumps and lights are helm controlled.
Lots of additional tasks: Suzuki harness to the helm. Pull steering hoses. Wire runs for hull LED, auto-pilot pump, and wash down pump. Re-purposed I/O blower circuit for bait tank LED. Rigged new DF300AP. Added new connectors to all existing circuits and spliced and cut as required. Relocated battery charger, bilge and wash down pumps. Ran new fuel line and installed new filter assembly.
With the engine mounted and the electrical system sorted, I had to do more fiberglass repairs. Removing the I/O blower system left 2 cutouts on either side of the hull. These were pretty easy to glass and fill and gelcoat. I ordered from Spectrum (iboats.com) since they have a matched gel coat color for my '98 Pro-Line. I have to say it was a pretty good match for a 20 year old boat. I can see it because I know where to look.....
Using 20# Coosa, I glued in some pieces to form the aft corner of the engine cut out. I glassed and filled and rolled on a few layers of gelcoat using a fine foam roller (learning some tricks along the way). This resulted in a pretty good finish! Not mold-like but pretty smooth anyway. Didn't I say this is a 20 year old boat.
I made a hatch cover and rolled on some Kiwi Grip to match my existing sole of the cockpit. I enlarged the vertical cut out slightly for better access. I had a custom cover made from boatoutfitters.com. They also did the cleaning station for me.
This last picture shows the finished cockpit and transom. It is so roomy and more fishable. No more jumping over the doghouse of the I/O. Easier to open the fish boxes. Remove the hatch cover and I have excellent access to the batteries, pumps, filter, and components.
OK, so many of you must be wondering about handling and performance.
I swapped a 320 hp VP for 300 hp Suzuki. Once upon a time, this hull was available as either an I/O or a bracketed OB. Stainless Marine was the OEM supplier at that time. During my conversations and due diligence, I was very reassured that this hull was a great candidate for this conversion....
The Suzuki is much more quiet across the entire RPM range. I traded away about 400 pounds but the engine sits farther aft. The boat's stern floats about 2 inches higher than before. In the first photo of this thread, you can see the old scum line for comparison. When drift fishing, I don't get water sloshing in under the transom door like I did before; maybe it is because the stern is a bit higher or maybe it's due to the full width bracket. The bow rise coming onto plane is very slight. With full tabs and trim, I can plane at about 15 knots.
The two best propellers I have tried thus far are the Suzuki 3 blade in 18.5 pitch and a Powertech OFX 4 blade in 19 pitch. I am getting anywhere from 2.2 to 2.6 mpg at 30 mph depending on fuel load with a full curtain package using the PT prop.
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