Merucury 2.5 EFI 280, duarbility

[St]

Hi everyone!

How is the durability on a completely stock merc 280 if I only will be running 5000-7250 on a pleasureboat? Will it fall apart every 100 hours? I have searched the internet but couldn't find much about durability when using it as a pleasure motor completely stock.

I'm new to high performance engines (and to this sight) and just want to get a fell of what I could expect. :very happy

 

[suicidealli]

A 100-125 hours is normal between rebuilds. If your turn them over 8000 less than 100 hours, over 9000 less yet. That is what I have found using premium 100 % synthetic oil.
They will run longer, but it will be more costly when you rebuild it. The more wear on the ring the sharper the edge gets. When it gets wore, and sharp it will cut the nic coating. when the piston reaches the end, and makes the turn to go back down the ring will cut the nic..

Roy

 

[chad202]

I had 100 hrs on my 260 when I took it sucked up some trash in the water jacket. Felt it sticking a ring/piston so shut it down. Had it rebuilt and looked at the rings and all except the one that was bad still were gold all the way across. They looked great. Probably couldve gotten another 100 or so hrs out of them. Now I probably only had an 1 or so over 7000. I mainly just cruise 5-6k rpm.

 

[Dave Hensley]

The factory plated finish is only as good as the person operating the final honing process. A good plateau finish that was honed in reverse to get all the sharp edges knocked off will last a long, long time. Nicom or Nikasil is an art not a science. The original Mahle version was far superior to what is out there now. As Roy says rpm's make an exponiental difference in life. My money is spent with Millenium plating as there quality control is the best I have seen on the final cylinder finish. My $.02.

 

[St]

Thanks for great inputs so far!

 

[St]

When rebuilding a engine like this on a regular basis (every 120 hours or so), what does one actually do and how much does it cost depending on what has to be done?

 

[catfish123]

There are as always, many different opinions on just how long these motors can go between rebuilds. Obviously, how the motor is run, and at what rpm's is a big contributing factor. I have been told by someone who I FULLY TRUST, that if you aren't out there hammering it all the time, and running real big rpm's, that most of these motors will go 150-200 hours with no damage at all. Surely, there are exceptions in the actual results regarding all opinions. I purchased a TDC gauge from Jay Smith, and also got the dual gauged leakdown tester, and a compression testing gauge. I plan to check my motor out periodically to see how it's really doing. My pockets aren't deep enough to just have it rebuilt every 100 hours unless it's warranted. I open it up every now and then, but that is not the boat's primary use. Even when I do open it up, I'm not holding it there mile after mile. I hope now that I have not jinxed myself by offering up this information.............LOL

 

[suicidealli]

There are so many variables to factor....... If someone has already rebuilt it before. How much wear was on the used pistons. How much wear on the nik. If a wore piston is used for a rebuild it will rock back and fourth more, and wear the nik. Big difference between a hone job with new rings, and a total rebuild job. If you put a couple hundred hours on one just plan on a nik job, and new pistons for the rebuild job. 100-120 hours you could get off with a hone job, rings, bearings, etc.. Pistons may be ok...

All these factors depends on rpms, oil, hours.. I have tore them apart and couldn't believe how great it looked.. Also couldn't believe how bad some have looked.

I pulled a part a 2000 model 280 this week. The block has little to no wear on the sealing rings. The bearings look great. The needs a nik job. The rings were wore out a long time ago. It had 145 lbs on 5 cyl and 135 on the other. Rods are perfect. It is on its way to ruck for a 1000 nik job with shipping, and honing. You just don't know til you tear them down....

Jay smith has prolly built more 260/280/300 than most. Read some of his threads on it.. Do all the research you can to educate yourself about these engine. Diamond marine has built to many to count too.


Roy

 

[2003225X]

The rings in a 280 were designed for 200 hours of wide open throttle use. I agree 100% that there are a lot of variables that can change rebuild time. If you are turning high rpms all the time, you will be tearing it down a lot. If you run it "reasonably" 150-180 hours shouldn't be out of the question.

When one is torn down, you might as well do it all at that point. Rings, bearings, check pistons and the nik, etc.

If you want the knowledge and a great guy to talk to and deal with, then Lee Sanderson is the person to go with.

 

[john w]

I recently traded a motor for a 99-280 sport, it had 90 hrs and was wore out. the cylinders looked good but the pistons and rings were shot. the motor had a 7700 limiter in it, i know he ran klotz r50 in it. crank bearing shot, so i guess you never what you get.

 

[racerx]

How about Geislers 280,, original 350 hours and still rockin,,he saved money in the long run,for the cost of his 1 rebuild in the future..

 

[michael j giesler]

yep still running strong rev limitor still on always ran real gas with a spalsh of merc quickcleen and merc high perf 40 to 1 i want to go to 400 hours then send it to merc high perf as a product tested for 11 years :big grin and then get a freee rebuilt

 

[procomp]

yep still running strong rev limitor still on always ran real gas with a spalsh of merc quickcleen and merc high perf 40 to 1 i want to go to 400 hours then send it to merc high perf as a product tested for 11 years :big grin and then get a freee rebuilt

Have you had to change anything?
Hoping to run my 280 for the first time next weekend
My buddy bought a brand new 280 several years ago and he's around 160 hours. I'll have to let him know about yours. He's pretty easy on it

 

[St]

Alot of great answers so far! Thank you very much!

 

[St]

What compression numbers could you expect from a healthy stock 280?

 

[suicidealli]

Depends on elevation. Sea level 150-155. 1000' above sea level 140. Average for a healthy stck motor. This is what I have found.

Roy

 

[St]

Thanks! =)

 

[JaySmithRacing]

I find 280's to be very reliable and a great recreational engine. I see Nikel plated motor leakdown high with as little as 80 hours and as low with 200 hours. Guess its the luck of the draw as well as use ,abuse, oil , fuel quality, etc...

I use either or of the two WIS. platers ( US Chrome-Melinium) with great luck, no matter who the blocks are plated by I always use a Goodson ball hone for NIK and afterward a plateau brush afterwards to knock the elevated plateau off seems to save ring life for the motors I build...

BTW: You'll love your 280 its a torque animal !!!!!
Jay

 

[St]

I asked for the compression numbers on the motor I'm intrested in.
The motor is completly stock and has run about 100 hours since new.

The compression is between 130 and 140 on each cylinder (at sea level I think). Should I be concerned? Are these numbers low?

 

[2003225X]

If you are down to 130 I would be taking a look at things.

I think Roy is right on... My dad's 280 is 151-153 on all cylinders around sea level.