Offshoreonly.com - What is Considered High Hours on an Engine?

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Quote:

Originally Posted by JFT (Post 4477808)

I had the same approach when discussing it with a potential buyer stating that 97 % of the hours were done at low rpm (800-2000).

The reply was, if you are selling a Ferrari with 30,000 miles, no one will care about the rpm data, it's too high mileage.

There always seems to be a lot of activity on 40k+ mile 348's.

Not that I would ever want to own one, idle or not.

I call this incorrect. If you are not stressing the engine because of low speed it should last forever if maintained.

I have run outboards for 40 years and 350 hours is nothing to worry about. My new 300 xs should easily run another thousand hours with only routine maintenance. The only way that motor is hurt is either neglect or abuse!

Hours under 1000 aren't really a concern to me on any boat I have bought used. I'm more concerned with service records and receipts for work done on the motor over the hours its been in service. And I am a big proponent of warm up, especially on older carbourated stuff Drives me crazy to see guys come off the ramp and fire a motor, only to let it run for a minute and then drop the throttle. So hard on any engine when parts aren't in their happy places yet .

1230 hours on my still sealed original 500 efi!!! No top end job done yet either!

Quote:

Originally Posted by jeff32 (Post 4478268)

1230 hours on my still sealed original 500 efi!!! No top end job done yet either!

Your my hero and inspiration! I just rolled over 600 this season and trying to catch you

I know i'm playing risky a little bit, but still feel confident since it has always been run easy... Before taking them out for rebuild, i need to find a way to read them see the number of hours run in the different rpm range... And compression test before rebuilt also, just for curiosity how it still holds!!!

Quote:

Originally Posted by jeff32 (Post 4478268)

1230 hours on my still sealed original 500 efi!!! No top end job done yet either!

You are now tempting me to stick to my 300XS's...

Quote:

Originally Posted by BUP (Post 4477833)

Depends how well its all been maintained from day one. Customers boats that I have maintained with 1200 hours in better condition and running conditions than new customers boats with 50 hours on it.

97 % of hours at 800 to 2000 rpms is not were an engine should spend its time to help with motor longevity. Actually that is like lugging and trolling the engine all the time.. Kind of like sitting idling your car 97 % time. Not going to last. Most marine engine run rich at very low rpm's and 2000 rpms is lugging a marine engine. That's like running your car up a steep hill all day in 5 the gear lugging the hell out of it.

You want marine engine that has ran most of its time at 70 to 75 % of its duty cycle.

Just an Example MAX - WOT 6000 RPM's - a good place to see rpms at would be 4000 to 4500 most of its run times.

Couple thoughts. With such a high percentage at 800-2000, I'd bet over 99% of that 97% was at idle or no wake speed, not at the lugging RPM where you're in the middle of climbing out of the hole. There are a few idiots who plow around like that but this sounds like trolling, so very little load. Aside from maybe running rich and fouling plugs so they need replacing, is there anything else about running at idle which lessens life more than duty-cycle use? HAS to be lower stress at idle on most components, no?