Hours = miles ?

[COOL CROSSBOW]

I never learned how to figure out how many miles = how many engine hours. These 502s have 200 hours on them and what is the time to change the oil.

[Ghost]

I never learned how to figure out how many miles = how many engine hours. These 502s have 200 hours on them and what is the time to change the oil.

I'm a couple of beers in, but are you asking when to change the oil? I would say that if you have taken possession of a boat I would change the oil right away before running it as a matter of principle. From then on, what, maybe every 50ish hours or at least once/season? Bit of a SWAG, lots of folks will know better, but FWIW....

[Just Say N20]

Most everyone I know seems to either change at 50 hours, or at the end of the season if they didn't make it to 50 hours.

If you think about it, 3,000 miles seems to be the "accepted" norm for changing car oil, and most car engines roll those miles on, rarely going over 3,000 rpms, with most of the time probably 2,200 ish, with a fair amount of coasting.

Most of us run our boats 3,000+ rpms. Which in a car would be like pulling a heavy trailer up a 2,000 mile long uphill going 60 in 2nd gear.

Cheap insurance. :)

[The Hedgehog]

It all depends on the motor. I have to change mine every 10 hours (and it needs it). That is necessary with big hp blown motors. I think that the blue N/A motors are good to do around 20 (someone correct me if you have the exact numbers). A regular 502 could go between 25-30. I am not sure that I would try for 50 hours but it might not be unreasonable in motors that don't work that hard.

[osur866]

I change mine every 25 hrs. along with lower unit oil at the same time, book says every 50 hrs. but I think every 25 hrs. is cheap insurance, plus most of us run them a little harder than average I'd think. Steve

[MOP]

Like mentioned above my feeling, for normal cruisers 50 hours or end of season. Our boats which get run quite a bit harder 25 or less depending on how heavy your hand is or how much HP you are making. Many forget or do not realize the heavy loads on a marine engine. In your car you barely have any throttle on at speed, but in your boat it has a constant heavy load.

[LKSD]

It all depends on the motor. I have to change mine every 10 hours (and it needs it). That is necessary with big hp blown motors. I think that the blue N/A motors are good to do around 20 (someone correct me if you have the exact numbers). A regular 502 could go between 25-30. I am not sure that I would try for 50 hours but it might not be unreasonable in motors that don't work that hard.

This is about the same schedule I follow & if the hours arent met, I still change eng & drive oil before winter layup during the winterization & preventative maintainance at that time. :) Jamie

[Air 22]

It all depends on the motor. I have to change mine every 10 hours (and it needs it). That is necessary with big hp blown motors. I think that the blue N/A motors are good to do around 20 (someone correct me if you have the exact numbers). A regular 502 could go between 25-30. I am not sure that I would try for 50 hours but it might not be unreasonable in motors that don't work that hard.

:yes::wink:

[COOL CROSSBOW]

Thank guys.

[BUIZILLA]

the rule of thumb for the auto/trucking/power unit industry is as follows, this is from a manufacturer's correlation warranty standpoint that WE deal with.... this is from our documented warranty submitted paperwork history of over 27 years tracking

city truck - 22/23 mph
auto/pickup - 29 city/31 rural mph
transit bus - 11/12 mph
over the road trucks - 36 fleet/37-38 owner operator mph
industrial engines - variable speed - 26 mph
industrial engines - fixed speed - 35 mph

for instance, my truck has 50,600 miles and 1737.6 running hours since new = 29.12 mph, anyone with a GM truck can check this and see what they get, you might be surprised how low it really is...

[handfulz28]

I had actually checked this last week. '01 Yukon 2500 w/180k miles and 5675hrs = 31.7mph avg.

On the oil change interval for a boat motor, Merc's manual listed 50hrs or once per season. That's for a stock engine but it really depends on how hot the oil gets and whether it gets contaminted with fuel.