I went through hell with my 3.5 NG and ended up packing it off to the factory in Jacksonville. The price differential between fixing mine and getting a new one was low enough that I just bought a new one. Because Hurricane Michael blew my pier and lift down, the boat lived in the water for 18 months with the NG's exhaust facing a long fetch which can generate 2-3 footers for short periods in a bad blow. I was running the generator once a week to ensure all was well, and then one day it did not budge with a fully charged battery. I pulled the glow plug and with a rag in front of the opening hit the starter. The engine rolled over easily and pumped a cylinder full of seawater into the rag. Reassembled and started ok. Then two or three oil changes to make sure all was well. Good thing I was starting it as often as I was. The new one is still not a lot better getting started, but it runs. I also found out that the manual is quite correct about running 30% antifreeze (ethylene glycol I believe) in hot summer water here. I was getting overheat shutdowns until I switched from 50-50 premix I use in my Yanmar. I run it HARD. My first 3.5 NG had no fuse in the power line to the 12 Volt DC exhaust fan, and when that piece of junk Jabsco squirrel cage fan motor seized up, the whole DC wiring harness burned up and filled the boat with white smoke at 2200 in an anchorage far from home on a hot night - I shifted bunks to my brother's Grand Banks 42 to which I was rafted. The new harness I ordered came with a fuse, hmmmm. However, I had a better idea. I was able to shoehorn a Vents AC brushless centrifugal fan of about the same CFM as the Jabsco back in behind the genny. In order that it not be subjected to a bunch of spikey voltages at genny start, I installed a 30 second time delay for it. I NEED that cooling fan down here, but others have said up north not so much. My boat has a 13.5 kBtu rooftop air conditioner as well as a 10 kBtu Dometic Turbo marine AC unit (upgraded from the inadequate and then failed 7 kBtu marine AC the boat came with). Believe it or not, my 3.5 NG can run both ACs because I installed Micro-Air Easy Start circuit boards into both of them reducing the startup surge by 70% - it is hard to hear it take on the load when the compressors kick in. I think all that could have sent a kid to Auburn on out of state tuition rates for a year. Oh, and I really like the local start rig (with integral hour meter) the new genny came with because it allows me to flip the motor lid and be right there on top of it to start it instead of the insanely located starting switch on the power panel the boat came with - it's OK sometimes, but not always the best, especially with no hour meter.
