Re: Motor oil...
 

I agree with Oregon specifically about the load and water factors. The bearing pressures within a marine engine are much higher than an automobile that gets up to speed and cruises most of the time. That's why a well taken care of automobile engine will most likely last 300,000 miles while a boat motor is toast after 1,000 hrs. Even if you avg 60MPH that is the equivalent of only 60,000 miles.

Re: Motor oil...
 

Oregondunes could not have said it any better! Frequent oil changes due to two extremes- periods of no use AND periods of extreme load/use.

Oil does a few things: Lubricating and cooling via reducing friction AND inhibiting corrosion while the motor is not running (storage). Metals are susceptible to rust/corrosion being stuck in the damp engine compartments!

On the 7.4MPI I went with the big boy oil filter M302. It is a few inches longer than the standard SBC/BBC filter. Does it really matter? Getting more filter surface area for the same price is a no-brainer if you ask me!

My SC21 has one of these and I thought they would be standard on all boats... Well they are not, now I will be putting one on the Shabah.

Oil Drain Kits | Marine Engines | Basic Power

Re: Motor oil...
 

And it gives us an excuse to get out of the house and go play with our toys :yes_grin:

For me it's peace of mind

And if something breaks it's not from the lack of maintenance

Re: Motor oil...
 

Well I appreciate the responses guys but I'm still not convinced. There just isn't enough science behind "peace of mind" or a "reason to play with the toys" LOL. And Oregondunes response makes plenty of sense up to a point but the fact is the boat simply does not spend the bulk of it's time at "100% load". I'm curious how you define what "100% load is? Nobody in a leisure boat setting anyways spends 100% of the time at wide open throttle while meeting or exceeding their weight limits all the while pulling a skier or tube. I can respect why you guys maintain the way you do I just dont see the reason for it so routinely thats all.

Either way though I'll be pulling mine out of storage this weekend and getting her ready for spring and I'll check everything then make the determination what needs to be changed and what doesn't.

Re: Motor oil...
 

A boat is a boat and a car is a car.
Comparing the two is like comparing snow to a volcano. LOL
I figure it this way.........."you can't jump out and push the boat".
I follow with "preventive maintenence" about the same as everyone else.
I'll be damn if I'm fixing my boat at the lake just cause I didn't maintain it.... on my vaca! My brother in law is notorious for breaking while on the lake. He doesn't fix anything til it breaks.
I haven't broke down in 15yrs. Knock on wood!!
As usual........just my opinion! :)

Re: Motor oil...
 

In a boat, if the prop is spinning the motor is under full load regardless of engine RPM. there is no coasting. of course the faster you are moving the more friction there is against it all causing a greater amount thrust necessary to move it and a greater amount of energy demanded.

in a car you can use gravity on downhill slopes. a boat never gets that opportunity, unless your going with a fast moving current or over a water fall.

Re: Motor oil...
 

Again, what oregon says! The marine motor knows no rest. Imagine always towing something in your car/truck. That is mocking the load he is referring to, minus the fact you can coast in a car.
So how I see it... You can do what you want to do and I can do what I want to do. Either way I will sleep good at night knowing my investment is well cared for. Regardless if it matters or not.
In reference to the recommended maintenance stuff, I work my bikes over like it is no ones business. Fresh oils, bearings, seals, blah blah blah. It is costly. But and the end of the day it is still like new and it is a 2005 model and it is my well used race bike. Still hauls balls and still draws attention like it was the model year new bike.

My good buddy has an older boat that they did a bunch of motor work to. Like valves, head work, port polish, balance, blueprint, etc. He said the motor oil in that boat gets changed once every 5 years if it happens at all. Still runs like a boss! Although it goes out half a dozen times a summer and is stored in a climate controlled garage.