300xs 101

[Fassster]

My marina has limited experience with the racing motors and will be hanging mine in a week or so - is there any need for an external fuel pump?? I would think not, but saw a post somewhere where someone did? Also, what gauges can I link up, besides the usual tach, water pressure, voltmeter? Thanks guys.

[Euroski]

I added an holley red pump to feed my 300xs. Just didn't like the idea of the engine having to suck fuel through 10ft of fuel hose. Now it has all the fuel it wants.

[lazydays]

My 28' Skater has about 160 hrs on twin 300 xs motos. No external fuel pumps. Draws fuel about 4-5 feet thru standard Merc external spin-on fuel filters. No issues and we run it like we stole it ! Skater Steve

[Rayzor]

I've had several 3.0 liters on different boats and never ran a feeder pump. I'm rigging my first 3.2 right now with no feeder pump also. There is no mention in the installation manual or operation & maintenance manual of the necessity for a feeder pump or external fuel filter. The feeder pump and water seperating fuel filter are both located on the port side of the motor. The problem with a feeder pump in my opinion is that if it fails, you no longer have fuel to the motor, as fuel will not flow through the feeder pump once it has quit. Just one more part to fail and leave you floating. Just my opinion, call Mercury Racing if you still have concerns.

[jpf091959]

I have two 300xs', mercury says no need external pumps or slosh tanks. I took them all out.

As far a guages go. If you want smartcraft go to ebay, there are a bunch out there. I loose the signal to the guages. I was told the main harness is wrapped with foil for grounding and it gets damaged and that causes the problem. I don't believe it, but nothing I have tried works. If you want analog you need to buy a harness which converts the digital signal to analog.

I love my 300's but wish they had a little more power and RPM's, great on fuel, great around the dock and no smoke.

[XstreamVking]

Optimax motors dont need, xtra fuel filters, fuel pumps,(already have 2 electric) or anything else but a shot of merc engine cleaner in the fuel every other tank....This keeps everything clean and happy. Use the merc digital gauges (smart craft) Stay away from the digital throttle/shift. All the gauges just plug and play, add all you want. Once you get used to the fuel used, current consumption numbers and all the other features, you will wonder how you ever got along w/o them.... 300 XS motors are just the best motor out there, period.....Yer gonna love it...

[Fassster]

Thanks for all the great info. Looks like no external fuel systems. I wish the Merc digital gauges weren't so crappy looking and that Livorsi made something with carbon fibre faces for the application....

[xsflight]

I would get a new smatcraft harness and guages as well. Very valuable info, warning/alarm system with descriptive text. helped to keep me out of trouble a few times already.

[Fassster]

Looks like I am going to go with the new Mercmonitor system. One single gauge gives you every parameter you could possibly need; tach, gps speed, fuel and oil levels, voltage, trim, psi, optimum trim/rpm for fuel eceonomy, etc. Im gonna mount it in a single pod in my Cougar dash, and use the rest of the dash for other stuff, just not sure what. I think slowly but surely the days of dashes with 20 gauges will be gone. The only reason to keep them is looks/tradition.

[XstreamVking]

I think the merc stuff looks good, just get a cover for them to keep the sun off them. The led gauges will degrade from the uv's and heat. Takes time for it to happen just a heads up for you.

[Double Rigged]

Livorsi has a complete line of Smart Craft Gauges with whatever color/bezel background you want.
If you use the Merc Monitor it has a NMEA 2000 output which will feed any of the GPS plotters that have a gauge displays.