When I bought my 2004 300DA in 2011 the previous owner had just replaced the port engine with a long block due to an injector failure burning up a cylinder. The starboard had 640 hours on it. I bought it with no concerns about the remaining life of the starboard. Potomac River boat with 350 Mag engines.
The injector duty cycle will increase. The duty cycle is the relationship between when the injector is open and closed. The larger displacement the engine the greater duty cycle will be demanded on the injectors. If you should operate the engines continuously at high RPM / load the injector duty cycle will increase say from 80 percent to 95 percent; they will get hotter and tend to fail due to heat in extreme situations. I would never operate injectors over 95% continuously. Plus in extreme cases the ECM simply can't cope with the higher duty cycle demand.
What is necessary then to install a larger engine in place of the 350's that were stock ? I know that it does take place.
First regarding the injectors - I don't know how hard you run your boat. If you cruise on plane and generally easy on the engines then you should be good with the injectors you have. I would definitely send them out and have them cleaned and calibrated; RC Engineering is a good company to do that. If on the other hand you run the engines hard and at high load/rpm's then you need to step up to larger injectors - it's that simple.
Do you mean that the levers aren't centered when the neutral detent is met, or that the outdrives are still driving with the levers in neutral with the detent met? If it's the prior, the levers can be removed and re-positioned by loosening the Allen screw on the bottom of the lever. Push them to full forward WOT, and you'll see a small hole at the base of the lever. That's where the Allen resides. If it's the latter, you have some cable adjustment/replacement in front of you. I just went through this with my '92 and was able to get some cable lube snaked down by opening the controls. Kinda funky, but it got me out of the cable replacement camp. They work so much better! To get to them:
The chrome cover can be removed by pressing in a little plastic dot along the forward edge. Mine promptly broke, so I'm guessing a dot of RTV will have to do as it's going back together. 'Can't blame it after thirty years... What you don't see here is the two through-screws fore and aft that hold the controls in place, as I already took them out. They slide left-to-right through the four corner brackets.
Like @Deak pointed out, that's pretty normal, assuming you're more interested in getting full throttle in Forward rather than Reverse
. It makes it easier to jockey the two to get the engines to sync when the levers are straight up as compared to 'way forward. However, you're correct; they can be repositioned. Find the Allen screws on the bottom of the levers (opposite the hand grip), and you can reposition them. Note that they're splined and have to be pulled off to move.
Nater, as I stated prior, this was quite in depth. again thanks. I Have an 86 300SD and my shift cables are terrifying. They chose to stick or get stiff when you need them most, in and out of the dock. I am thinking of replacing them this haul out. Re-reading your post, I was wondering if I should take the unit out like you did, shoot some oil down both sides or just rip them out (by the way, what oil did you use)? Is there a way to test to see if there is freedom without putting everything back together? If I have to spend the money for a full replacement, ok. Just don't want to spend money I don't have to.Do you mean that the levers aren't centered when the neutral detent is met, or that the outdrives are still driving with the levers in neutral with the detent met? If it's the prior, the levers can be removed and re-positioned by loosening the Allen screw on the bottom of the lever. Push them to full forward WOT, and you'll see a small hole at the base of the lever. That's where the Allen resides. If it's the latter, you have some cable adjustment/replacement in front of you. I just went through this with my '92 and was able to get some cable lube snaked down by opening the controls. Kinda funky, but it got me out of the cable replacement camp. They work so much better! To get to them:
The chrome cover can be removed by pressing in a little plastic dot along the forward edge. Mine promptly broke, so I'm guessing a dot of RTV will have to do as it's going back together. 'Can't blame it after thirty years... What you don't see here is the two through-screws fore and aft that hold the controls in place, as I already took them out. They slide left-to-right through the four corner brackets.
Once these are out, pull the controls up and away. Watch for the cabling on the left controller, as there's no easy way to disconnect it from below. I was able to get enough slack to perform my work without disconnecting them. Be aware; mine were a royal PITA to pull out. It took much rocking and swearing to get them out of the fiberglass dash.
Remove the two screws near the blue label to access the inner workings:
Once inside, these actually looked pretty good, considering their age. I merely re-distributed the grease around the wear spots (smeared it around with my grubby finger) and shot some cable lube down the shift and throttle cables.
Before going back together, reach inside with a small wrench and tighten the mounting bracket screws. Mine were crazy loose. Fortunately, they were lock nuts, so were still in place. Hopefully, you can get away without having to replace the cables.
It wasn't as bad as I originally made it seem (time heals all wounds?) since the worst part was figuring out how it comes apart. Once I was in there, I was able to dribble some lithium chain and cable lube into the cables. It definitely made a huge difference in my case. YMMV
Absolutely! When I first got into mine, the cables were so stiff that I almost couldn't actuate the shift cables while holding the control mechanism in my hand. I'm thankful that the dash wasn't cracked from my earlier reefing on the levers! Once the cables were lubed, I could easily move the levers with one hand on the control box, and the other on the lever. It's certainly worth trying before snaking in new cables.
