How to be nice to a motor?

[NateCCIE]

So I am getting frustrated with my 93 Merc 502 mag EFI that has low compresion, burns oil, doesn't like to start after idleing. It only has 475 hours and AFIK fresh water use only.<br /><br />What is the best way to insure long service (years and hours) of a motor? <br /><br />What about things like Shutting down when sking, running only 75% throttle for longer cruses, WOT for only a little bits at a time after you're warmed up...<br /><br />I am looking at possibly only a top end rebuild (the leak down showed the intake valves having lots of leaks) and I want to make sure I do every thing I can to keep me out of the shop with expensive rebuilds.<br /><br />-Nate

 

[jeff13601]

Re: How to be nice to a motor?

The best thing that you can do is the proper maintenance. Change the oil regularly and the motor tuned yearly

 

[Trent]

Re: How to be nice to a motor?

Id run a decarb like Berryman's B12 from your local autoparts (or WalMart) or Seafoam. Just for a try...because of it being intake valves. Also run a higher grade of fuel. What is the temp the engine is running?? Sounds like a carbon problem??????????

 

[tommays]

Re: How to be nice to a motor?

 

[tommays]

Re: How to be nice to a motor?

it depends on what you find happened to the valves<br /><br />there were a lot of posts on 8.1 EFI motors this week about big blocks haveing problems with the port and starbord cylinder banks pushing water into each other <br /><br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=24;t=011985#000000 <br /><br /> http://www.boatered.com/forum/topic.asp?TOPIC_ID=58340 <br />tommays

 

[Olds Eddie]

Re: How to be nice to a motor?

I have started spraying fogging oil down the carb after I put her on the trailer and before I turn her off. It keeps the valve seats from rusting. I also am running taller risers.

 

[imported_scott_m]

Re: How to be nice to a motor?

Honestly, the best thing you can do after you get the motor right is to USE it. The more these marine motors seem to sit around the more problems we seem to have with rusting valve seats, oil leaks, etc. <br /><br />Just treat it nicely...as another poster mentioned, oil changes every 50 hours. When you fire up for the first time every day, give it a couple of minutes to warm up. Then, when you cast off, be easy on the throttle for another 5 minutes or so until all the fluids and parts come up to temp. Operate the boat throughout the RPM range, but of course sustained WOT WILL wear you out sooner. But then again, lugging the motor between displacement and planing speed will put a ton of wear on it too.