BryanTuvell

I have a 2001 OM series (last ones built I am told) 502MAG that was new in my new boat, changed oil at 10 Hours, 25, and 50. I am at 65 hours and again low on oil.
She is often a quart, quart and a half low, like today.
I use the Merc Hi Perf stuff as recommended.

No leaks etc, is this burn rate normal on new 502's?

She had a fairly easy brake in period the first 10 hors but I run her fairly hard now, mostly around 4000 to 4200 RPM's all day long, and of course some 5200 stuff when needed.

Also twice recently she was fluded, hard to start, moved throttle up some, kept cranking and she fired, two seperate incidents, seperate weekends etc. Both after hard runs, stopped for a break and had the problem... I could smell gas gas both times.
Water seperator is original.

Thanks, Bryan

BryanTuvell

Thanks for the reply, I love text book answers, never saw the 1-5 hour rate quoted before.

I wonder why it burs so much and why she floods.

Thanks, Bryan

MACDAD260

Formulafastech,

"I fix things till they can't be fixed"

Great signature! LMAO.

Lots of people do that, they just don't admit it.

Welcome to the board.

Doug

Vinny P

Bryan;

Check out this site. http://www.sterndrives.com/bulletins/mc/99/EN_007.PDF It explains the hard start that you experienced. I have also had this happen to me. It seems to be a common problem with Mercs' EFI motors. I personally attribute it to the fact that the motors don't have a fuel return line. I think that the fuel that lays in the fuel rail gets too hot and causes vapor lock.

cast

502 BURN OIL DO A LEAKDOWN TEST ON MOTOR. YOU WILL FIND OUT YOU HAVE BAD RINGS

BadDog

Running hard and that amount of oil consumption is fairly typical. This topic had been covered before about a year aqo on the board. You may try running a straight 40 wt. The 40 wt. seemed to help reduce consumption in my 502. I since switched to Mobil 1 20-50, consumption was about the same as the 40wt.
Tim T.

BillR

Bryan,

Do NOT advance your throttle! You have EFI, and advancing the throttle does not help the problem. My old 502 had the same symptom. Just wait a minute or two if possible, then crank it and it will restart.

Oil usage on a 502. . . .thats normal relax!

BryanTuvell

Thanks Bill, if I do not advance the throttle she just cranks, only happened twice.... could be a fluke!

I just emailed the club for todays plans....
B

Gearhead99

Engine probably has very low drag piston rings.

Have seen many burn "a little" oil. I wouldn't worry.

Put synthetic 20-50 in it. Either Amsoil or Mobil 1. You'll be glad you did.

BryanTuvell

All that I have read and been told the last 2 days I think I am fine, got to love the OSO gang when you need "info"....

I am staying with the Merc fluids as a precaution since I have a
5 year warranty, I keep meticulous records so if I ever have a problem etc... most say I change fluids to often but I think it needs it, and damn sure doesn't hurt.

Hot and Sunny here in VA, about to go boating!

Thanks again guys.
Bryan

PS, someone ask how I broke her in, no long idles, no prolong "same" RPM, no WOT and above 3500 was increments of 200 RPM per our manual. After 10 hours I ran her like any other engine.