the 496HO's (stock) max RPM is 5000 what would be the the highest ideal cruising RPM for 2 hour runs at a time?

thanks

3800-4200

Ideal in terms of what? Fuel consumption, wear and tear, speed?

I would think you can run it at 4K all day long without harming it. You will be using al ot of fuel though. I usually run mine at around 3500 on long runs. Mostly because that yields a good cruise speed too.

Go to Boattest.com and see if they have your boat & motor combo tested. They did for my Baja 242 with the 496 mag and it turned out the best "fuel efficient" cruising rpm was 3k.

My Best Cruise Was At 4000 Rpm's In A 30' Cigarette Mystique. It Was In A Twin Step But It Returned A 1.2 Mpg At 65 To 67 Mph.

mine seems to be right around 3200-3400.

i am not really looking for saving fuel, just what would be the highest rpm i can run the engines on for 2 hours at a time without causing any damage, or shortening the life of the engines faster than the life it should have under normal circumstances. for example can i run them @ 4200rpm for 2 hours without increasing the wear and tear too much or would that be the same like max rpm which is 5000

thanks
jack

anyone?

I'll jump in here though I don't claim to be an expert. I have a 2001 with 240 hours on it. I bought it new so I know how it has been run and cared for. I can't say I have ever run the 2 hours you are referring to but I have made several long runs at over 4000 and I feel very safe doing it. I don't think I would run a long time over 44-4500 but I would not worry about anything less than that. As long as you have good fresh oil in it I just don't think you can hurt these things.

The gage that every boat should have and that would answer your question is an oil temp gage. Running extended high rpm distances without knowing oil temp is like playing russian roulette. You need this temp to stay below about 230f at cruise (whatever the rpm may be) to not shorten the life of the engine rotating assembly.

BT