PSG-1
Well-known member
Taking out the center strake will definitely help with getting rid of some cavitation.
I know what you're saying about the motor mounting bolts being through-bolted with a nut on the bottom side. You might be able to see from the pictures that when I did the mount rails for the original aluma-jet, we used carriage bolts, that went from the underside of the rail, and the nuts were secured to the top side. Only one problem. Once I welded those rails in place, I had no way of being able to replace a carriage bolt if it corroded, or sheared.....thank God that never happened.
So, on the HO engine, I simply drilled and tapped into the mount rails for the mount bolts, actually I added pieces of 1/2" thick aluminum on the inside of the square tube (doing a plug weld at either end of the thick piece to secure it in place.) I had some concerns about them holding, or possibly stripping out, so, I used red locktite, and I was very careful not to over-torque the bolts when I installed the mounts (I have a REALLY bad habit of shearing bolts, getting haywire with over-torquing) Anyhow, so far so good, all 8 of the bolts (2 at each mount) are holding securely.
As far as your cables.....if it turns out that factory cables won't be long enough, don't worry about it too much. For your steering cable, you can use a Teleflex cc633 series cable, it has the 10-32 threaded ends, much like the factory. However, I believe in doing things with overkill, so I opted for the cc694 series (later changed to cc640 designation) which has 5/16x24 threaded ends. Of course, if you go with the larger cable, you will have to drill and tap the ball joint fittings for 5/16x24 threads....not too difficult if the ball ends are made of bronze, but if they are stainless, you have to be very slow and cautious about it, or you WILL break a tap.
Throttle cable isn't too hard to make, either. Some conduit for motorcycle control cable, and some 1/16 stainless cable will do it. Then you just need a few fittings, and a way of securing each end of the cable so that the conduit remains stationary, so the cable is the only thing moving back and forth. And of course, you need barrel nut fittings for the ends. You can buy them already made.
Let me know if you run into any problems with your cables, I can save you a lot of the headache that I went through the first time around.
And as far as the gas tank being in the front, that shouldn't be an issue, as long as the pickup tube reaches the bottom of the tank, and you don't run it too low on fuel. If it's possible, get a tank with baffles, or if you are building your own tank, install a baffle (something I should have done)
Heck, with my boat, I'm actually making gas run uphill from one tank to the other!! Now, that's a trick. Since the HO engine uses a fuel pump that goes down into the fuel tank, the pump is on the port side tank, which is mounted further forward than the starboard tank.
So, how do I get the fuel from the starboard tank, to the port tank? With an equalizer hose. At the bottom front of each tank, I have a welded 1/4" NPT female aluminum fitting, with a barb elbow screwed in place, and a 1/4" hose that runs from the starboard tank to the port tank.
Initially, I was having problems with the port tank running empty while the starboard tank was staying full. I fixed that by using a set of check valves on the fuel vent lines. On the starboard tank, the check valve is oriented for air to flow towards the tank, so it draws in on this side. On the port tank, the check valve is oriented away from the tank. So, what happens is when the fuel expands in the starboard tank, it pushes towards the port tank, filling it as it's drained. Now, the starboard tank will run dry while the port tank stays full. Ideally, I wanted both tanks to always have the same level in them, but as long as the fuel is making its way to the port tank where the fuel pump is located, it works well enough.
Having said that, you do need to install a check valve on your tank, to allow air in, but not out. If you notice on most jet skis, when you open the fuel cap, there is internal pressure. This internal pressure is what helps keep the fuel flowing to the system. Without it, you're going to be relying on gravity to feed fuel through the system, this can cause lean conditions at high speed, causing engine damage.
Anyhow, keep 'er going, and keep us posted!
I know what you're saying about the motor mounting bolts being through-bolted with a nut on the bottom side. You might be able to see from the pictures that when I did the mount rails for the original aluma-jet, we used carriage bolts, that went from the underside of the rail, and the nuts were secured to the top side. Only one problem. Once I welded those rails in place, I had no way of being able to replace a carriage bolt if it corroded, or sheared.....thank God that never happened.
So, on the HO engine, I simply drilled and tapped into the mount rails for the mount bolts, actually I added pieces of 1/2" thick aluminum on the inside of the square tube (doing a plug weld at either end of the thick piece to secure it in place.) I had some concerns about them holding, or possibly stripping out, so, I used red locktite, and I was very careful not to over-torque the bolts when I installed the mounts (I have a REALLY bad habit of shearing bolts, getting haywire with over-torquing) Anyhow, so far so good, all 8 of the bolts (2 at each mount) are holding securely.
As far as your cables.....if it turns out that factory cables won't be long enough, don't worry about it too much. For your steering cable, you can use a Teleflex cc633 series cable, it has the 10-32 threaded ends, much like the factory. However, I believe in doing things with overkill, so I opted for the cc694 series (later changed to cc640 designation) which has 5/16x24 threaded ends. Of course, if you go with the larger cable, you will have to drill and tap the ball joint fittings for 5/16x24 threads....not too difficult if the ball ends are made of bronze, but if they are stainless, you have to be very slow and cautious about it, or you WILL break a tap.
Throttle cable isn't too hard to make, either. Some conduit for motorcycle control cable, and some 1/16 stainless cable will do it. Then you just need a few fittings, and a way of securing each end of the cable so that the conduit remains stationary, so the cable is the only thing moving back and forth. And of course, you need barrel nut fittings for the ends. You can buy them already made.
Let me know if you run into any problems with your cables, I can save you a lot of the headache that I went through the first time around.
And as far as the gas tank being in the front, that shouldn't be an issue, as long as the pickup tube reaches the bottom of the tank, and you don't run it too low on fuel. If it's possible, get a tank with baffles, or if you are building your own tank, install a baffle (something I should have done)
Heck, with my boat, I'm actually making gas run uphill from one tank to the other!! Now, that's a trick. Since the HO engine uses a fuel pump that goes down into the fuel tank, the pump is on the port side tank, which is mounted further forward than the starboard tank.
So, how do I get the fuel from the starboard tank, to the port tank? With an equalizer hose. At the bottom front of each tank, I have a welded 1/4" NPT female aluminum fitting, with a barb elbow screwed in place, and a 1/4" hose that runs from the starboard tank to the port tank.
Initially, I was having problems with the port tank running empty while the starboard tank was staying full. I fixed that by using a set of check valves on the fuel vent lines. On the starboard tank, the check valve is oriented for air to flow towards the tank, so it draws in on this side. On the port tank, the check valve is oriented away from the tank. So, what happens is when the fuel expands in the starboard tank, it pushes towards the port tank, filling it as it's drained. Now, the starboard tank will run dry while the port tank stays full. Ideally, I wanted both tanks to always have the same level in them, but as long as the fuel is making its way to the port tank where the fuel pump is located, it works well enough.
Having said that, you do need to install a check valve on your tank, to allow air in, but not out. If you notice on most jet skis, when you open the fuel cap, there is internal pressure. This internal pressure is what helps keep the fuel flowing to the system. Without it, you're going to be relying on gravity to feed fuel through the system, this can cause lean conditions at high speed, causing engine damage.
Anyhow, keep 'er going, and keep us posted!