How-To

Keeping your bass boat alive, part 12

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<em>All photos and captions by Mark Hicks</em><p> <em>JACKPLATE AND PROP REPLACEMENT</em><br> My used bass boat did not have a jackplate or a stainless steel prop when I bought it. Both are necessary to achieve peak performance and fuel efficiency. My boat’s top speed with the aluminum prop that came on the 1999 Mercury XR6 150 hp was about 45 mph. That just wouldn’t do.<p> I didn’t feel comfortable installing a jackplate myself. I don’t have a winch or the tools needed to lift the outboard. Attempting to detach the outboard without a winch could have resulted in costly damage.<p> I wisely enlisted Blain Schwarzel, a superb bass boat mechanic at Schwarzel Marine in Hockingport, Ohio, to install the jackplate for me.<p> I elected to go with a manual TH Marine Z-LOCK jackplate rather than a more costly hydraulic jackplate. The sturdy Z-LOCK is made from 1/2-inch thick aircraft aluminum. It handles outboards up to 300 hp and is available in a 6-, 8- or 10-inch setback. I chose the 6-inch setback.
All photos and captions by Mark Hicks
JACKPLATE AND PROP REPLACEMENT
My used bass boat did not have a jackplate or a stainless steel prop when I bought it. Both are necessary to achieve peak performance and fuel efficiency. My boat’s top speed with the aluminum prop that came on the 1999 Mercury XR6 150 hp was about 45 mph. That just wouldn’t do.
I didn’t feel comfortable installing a jackplate myself. I don’t have a winch or the tools needed to lift the outboard. Attempting to detach the outboard without a winch could have resulted in costly damage.
I wisely enlisted Blain Schwarzel, a superb bass boat mechanic at Schwarzel Marine in Hockingport, Ohio, to install the jackplate for me.
I elected to go with a manual TH Marine Z-LOCK jackplate rather than a more costly hydraulic jackplate. The sturdy Z-LOCK is made from 1/2-inch thick aircraft aluminum. It handles outboards up to 300 hp and is available in a 6-, 8- or 10-inch setback. I chose the 6-inch setback.
Four hardened stainless steel marine grade 1/2-inch mounting bolts were needed to secure the outboard to the jackplate. The original stainless steel marine bolts that connected the outboard to the transom were used to secure the jackplate to the transom. The tube of grease pictured here is extremely important, as you will see.
Four hardened stainless steel marine grade 1/2-inch mounting bolts were needed to secure the outboard to the jackplate. The original stainless steel marine bolts that connected the outboard to the transom were used to secure the jackplate to the transom. The tube of grease pictured here is extremely important, as you will see.
Blain Schwarzel removes the cowling from my Mercury XR6 so he can install a Mercury lifting eye.
Blain Schwarzel removes the cowling from my Mercury XR6 so he can install a Mercury lifting eye.
After removing the plastic plug that protects against corrosion, Schwarzel threaded the Mercury lifting eye into the middle of the flywheel. Then he hooked a 1/2-ton winch to the lifting eye.
After removing the plastic plug that protects against corrosion, Schwarzel threaded the Mercury lifting eye into the middle of the flywheel. Then he hooked a 1/2-ton winch to the lifting eye.
Schwarzel lifted the outboard with the winch to take pressure off the bolts that hold the engine to the transom.
Schwarzel lifted the outboard with the winch to take pressure off the bolts that hold the engine to the transom.
Schwarzel removes the nuts from the outboard’s top two mounting bolts, which are accessible in the splash well.
Schwarzel removes the nuts from the outboard’s top two mounting bolts, which are accessible in the splash well.
Someone had previously installed “top hats” to the other two mounting bolts under the splash well and the boat’s back deck. This eliminated the need to remove the batteries or do other steps that would have been required to reach these bolts. Schwarzel simply removed the nuts from the outboard’s stern bracket on the outside of the transom.
Someone had previously installed “top hats” to the other two mounting bolts under the splash well and the boat’s back deck. This eliminated the need to remove the batteries or do other steps that would have been required to reach these bolts. Schwarzel simply removed the nuts from the outboard’s stern bracket on the outside of the transom.
With the nuts removed from the outboard’s mounting bolts, Schwarzel pulled the outboard off the bolts and away from the transom to make room for the jackplate.<p> Fortunately for me, the boat’s steering cables were long enough to accept the jackplate. That eliminated the expense of buying longer steering cables.
With the nuts removed from the outboard’s mounting bolts, Schwarzel pulled the outboard off the bolts and away from the transom to make room for the jackplate.
Fortunately for me, the boat’s steering cables were long enough to accept the jackplate. That eliminated the expense of buying longer steering cables.
Before bolting the jackplate to the transom, Schwarzel applies silicone around the mounting bolts to ensure that water says out. He favors black silicone for this because he can better see where it has been applied.
Before bolting the jackplate to the transom, Schwarzel applies silicone around the mounting bolts to ensure that water says out. He favors black silicone for this because he can better see where it has been applied.
Schwarzel applies grease to the self-locking stainless steel nuts before bolting the jackplate to the stainless steel mounting bolts. This is extremely important.<p> Without grease, threading a stainless steel nut onto a stainless steel bolt is likely to result in galling. This is a phenomenon whereby friction can weld the nut to the bolt and prevent the nut from being threaded into place. If this happens, you must cut off the bolt or drill the bolt out of the nut.
Schwarzel applies grease to the self-locking stainless steel nuts before bolting the jackplate to the stainless steel mounting bolts. This is extremely important.
Without grease, threading a stainless steel nut onto a stainless steel bolt is likely to result in galling. This is a phenomenon whereby friction can weld the nut to the bolt and prevent the nut from being threaded into place. If this happens, you must cut off the bolt or drill the bolt out of the nut.
After sliding the jackplate onto the transom’s mounting bolts, Schwarzel places a stainless steel washer and then a lock washer onto each bolt before threading on the greased nut.
After sliding the jackplate onto the transom’s mounting bolts, Schwarzel places a stainless steel washer and then a lock washer onto each bolt before threading on the greased nut.
Schwarzel tightens the nuts to the mounting bolts to lock the jackplate to the transom.
Schwarzel tightens the nuts to the mounting bolts to lock the jackplate to the transom.
Slowly tighten the nuts. The faster you tighten the nut the more likely galling will occur, even when using grease.
Slowly tighten the nuts. The faster you tighten the nut the more likely galling will occur, even when using grease.
Schwarzel attaches the outboard to the jackplate with the new mounting bolts. Before he did this, he determined which holes in the outboard’s stern bracket would get the outboard close to the proper engine height.
Schwarzel attaches the outboard to the jackplate with the new mounting bolts. Before he did this, he determined which holes in the outboard’s stern bracket would get the outboard close to the proper engine height.
The ideal way to determine the best stainless steel prop for a given bass boat is to test run the boat on the water with a variety of props. Few anglers have access to the various props needed to do this, including me.<p> I did online research, talked to marinas, boat companies and Mercury techies to get opinions on the best prop for my boat and motor combination. When I started this task, I was thinking in terms of a four-blade prop. Four blades generally hold better at crawl speed when you’re navigating huge waves on big water, such as Lake Erie.<p> However, Mercury’s three-bladed Tempest prop with a 23-inch pitch was recommended to me from several sources, including anglers who had a boat and motor similar to mine. The Tempest prop’s blades have a large surface area, which allows it to perform well at top end and at crawl speed in treacherous water.<p> The Tempest prop has proved to be an excellent match. My hole shot and mid-range acceleration are tremendous. Also, I’ve bucked big waves with the boat at Champlain, Lake Erie and Lake St. Clair and the prop has yet to lose its grip.
The ideal way to determine the best stainless steel prop for a given bass boat is to test run the boat on the water with a variety of props. Few anglers have access to the various props needed to do this, including me.
I did online research, talked to marinas, boat companies and Mercury techies to get opinions on the best prop for my boat and motor combination. When I started this task, I was thinking in terms of a four-blade prop. Four blades generally hold better at crawl speed when you’re navigating huge waves on big water, such as Lake Erie.
However, Mercury’s three-bladed Tempest prop with a 23-inch pitch was recommended to me from several sources, including anglers who had a boat and motor similar to mine. The Tempest prop’s blades have a large surface area, which allows it to perform well at top end and at crawl speed in treacherous water.
The Tempest prop has proved to be an excellent match. My hole shot and mid-range acceleration are tremendous. Also, I’ve bucked big waves with the boat at Champlain, Lake Erie and Lake St. Clair and the prop has yet to lose its grip.
After loosening the nuts on the side of the jackplate, I can easily raise and lower the engine on the transom with a wrench to get the precise height for maximum performance.
After loosening the nuts on the side of the jackplate, I can easily raise and lower the engine on the transom with a wrench to get the precise height for maximum performance.
Schwarzel eyeballs the engine height to get it close to the optimal setting. His years of experience with many different bass boats and motors helps him in this respect.
Schwarzel eyeballs the engine height to get it close to the optimal setting. His years of experience with many different bass boats and motors helps him in this respect.
With my boat and motor, Schwarzel wanted the water that flows from under the running pad to pass above the lower four water intake holes on the outboard’s lower unit and below the upper four water intake holes.<p> “The rule of thumb is that for every inch the outboard is set back from the running pad, you raise the engine height ½ inch,” Schwarzel said.
With my boat and motor, Schwarzel wanted the water that flows from under the running pad to pass above the lower four water intake holes on the outboard’s lower unit and below the upper four water intake holes.
“The rule of thumb is that for every inch the outboard is set back from the running pad, you raise the engine height ½ inch,” Schwarzel said.
Bear in mind that you must also include any distance that the transom may be set back from the running pad. Because my running pad ends about 7 inches forward of the transom, this allows for a higher engine height than with a boat that has a running pad which is flush with the transom.
Bear in mind that you must also include any distance that the transom may be set back from the running pad. Because my running pad ends about 7 inches forward of the transom, this allows for a higher engine height than with a boat that has a running pad which is flush with the transom.
I ran the boat after Schwarzel set the engine height at what he regarded as a good starting point. I hit 60 mph with the boat empty at 5,800 rpm. It runs 55 mph loaded at about 5,500 rpm, which is close to what I believe is Mercury’s recommended top end of 5,600 rpm.<p> Given how well the boat performs, I’ve found no need to make any adjustments to the engine height. Schwarzel knows his stuff.
I ran the boat after Schwarzel set the engine height at what he regarded as a good starting point. I hit 60 mph with the boat empty at 5,800 rpm. It runs 55 mph loaded at about 5,500 rpm, which is close to what I believe is Mercury’s recommended top end of 5,600 rpm.
Given how well the boat performs, I’ve found no need to make any adjustments to the engine height. Schwarzel knows his stuff.

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