I am new to perfopmance boating, and have had differing opinions on what is running 502EFi's to hard. Is it safe to run at 4000 RPM's for an hour at a time and an occasional run at 5000 for a few minutes? My boats is a 2002 sonic 31' with 140 hours and frequent oil changes. Some guys are saying it's to hard and motors won't last, my mechanic say's I can run all day at 4000. Any input would be appreciated. Thank's

usually optimum cruise rpms are 75% of WOT...(wide open throttle) so if your max rpm is 5000, then your optimum cruise speed would be 3750...your mechanic sounds right to me. unfortunately i cant keep my hands off the sticks for that long

Running hard for long distances sometimes requires mods to stock systems.You have to be able to keep temps under control, oil and water and you have to be able to control the oil in the pan to ensure a steady supply and to prevent foaming. A good set of gauges will tell you if you are having any problems.

put a 12 pitch prop on and then you can redline out of your canal.

you can run 4000 all day long.

If your oil temps are in check you can run at 4- 5k all day if you want. The camshaft has very slow / non-aggressive profile.

Steel crank, big rods, J&E pistons, low drag rings, a small hp vs cid, = many, many hours of abuse.

Speaking of low tension piston rings, these will burn a decent amt of oil from running at higher rpms. No big deal - nature of the beast - just make sure to check every 2-4hrs or so.

for gas, I know mine runs 16 gal/hour at 3000 rpm, and 28 gal/hour at 3500 rpm. that helps me stay in this area instead of the 51 gal/hour at WOT ! So can't answer if it could run for hours an hours at 4000 rpm!

Thanks for the input guys, oh and Hydrocruiser, that was some per retty funny stuff.

I ran my 502 crate at 5000 for almost 1 hour to get to the ramp before they closed with no problem.