2005 Moomba LSV questions-spark plugs and fuel usage

[jody]

i'm a relatively new Moomba owner this is my 3rd summer with the boat and so far we are very happy. i was wondering if you can point me in the right direction on a few things. i replaced my plugs the first year we got the boat as i didn't know when they had last been done. i put in at that time the AC Delco 41-993 plugs (which is what i was told replaced the original 41-932).i thought i would replace the plugs to start with and was wondering what your thoughts are on using a more standard plug and what numbers to look for in the AC Delco and or can or should i try an NGK...i see some numbers like NGKTR5...can i use a non platinum or iridum plug? should i go hotter or cooler plug?

This year for some reason we have noticed the boat has been using more fuel than in the past (we think this is the case) my fuel gauge is working and the motor runs fine based on starting idling and performance to what i can tell. i do notice even when the temp is cooler outside and the water isn't hot that my temp gauge on the boat runs at the higher end of where i normally see it? (i think...i don't always make note of where it is). everything seems to be working fine and running fine so i'm wondering if you have any thoughts. . also, do you think there's anything else i can look at doing other than plugs? does it have a thermostat that i should change? should i put a colder thermostat in if so?

any or all tips and tricks you can lend would be Greatly appreciated.
thanks
Jody
2005 Moomba LSV

[VA LSV]

Non cat motors do not require iridium or platinum plugs. I'm currently running NGK TR5 plugs. They were readily available from local auto parts stores and I didn't want to wait to order the marine version plug which is 1 heat range hotter than the TR5's.

As for motor running warmer than normal, check your impeller for wear and the tranny heat exchanger for obstructions.

[jody]

thanks. i installed a new impeller last season and the boat has five hours approx since. as far as the tranny heat exchanger i'm not familiar with that...any more info or a picture that you can share on what it is and how to check would be very helpful.

thanks
Jody

[VA LSV]

Follow your water intake hose from where it leaves the v-drive. The next connection it makes is the tranny cooler.

[jody]

ok...and take off the hose and look inside?...how to check?
thanks
for your help it's much appreciated.

Jody
2005 Moomba LSV

[VA LSV]

Take the hose off and look/feel for debris. It will look like a plate with a bunch of holes in it.

[Hayden]

We did this a couple years back and found a large salad clogging the tranny cooler. If you haven't already, consider putting a filter inline right after the main thru-hull.

[mmandley]

To help with your fuel usage and spark plug questions,

Before you can know to change to a hotter or cooler plug you need to run the plugs you have and then know how to read them. As in look at the sparking tip and see the colorization and that will point you to colder or hotter.

Your boat temp should always be 160-180

Note - the reason you normally change the Thermostat -

1. You want the engine to run cooler for a denser fuel ratio and more power.
2. You are concerned with it running to hot due to the amount of load you are putting on the engine.

Exp on my Vette factory was a 180 degree - I changed it to a 160 and this allows the cooling system to open sooner and not allow the engine to run as warm and thus makes a denser fuel / air ration creating more power. Uses more fuel LOL

Think of it like this - Generally when it’s Colder out cars have more power and better mileage once warmed up, this is because the air is more dense and creates better charge. More Air - Naturally tries to Lean your Fuel / Ratio so the computer will lower the fuel rate to match the air thus same power better mileage. The exact opposite happens when its hot out.

But running the Engine temp colder on purpose can cause the engine to stay in Cold Mode Longer which uses more fuel. Cold mode uses more fuel to force the engine to burn hotter and warm it up faster. ( This is why when the you first start the car the idle is higher, then later is lowers when the car is warm )

Excuse me if I am telling you stuff you know, I just rather be over informative then under.