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I have a 1999 Crver 356 with dual 440 engines. Under full power there is less than 3500 rpm's. Is that normal?
Posted: February 20th, 2018, 1:13 pm
by korchinsky
Under full power I cannot get over 3300 rpm's. Is that normal?
Re: I have a 1999 Crver 356 with dual 440 engines. Under full power there is less than 3500 rpm's. Is that normal?
Posted: February 20th, 2018, 3:02 pm
by mjk1040
No that is not normal, however if the props got changed for more low rpm thrust, you would lose top end rpms. Our 1998 355 with twin 454 ci engines top out at 4,400 rpms. We are going to need more info to help you here I'm afraid. You say 440 engines? Is that CI or HP? Is this a new boat to you or is this an issue that just happened on a boat you have had for awhile? Have all the fuel filters been changed? Since you said both engines only go tp 3,300 rpm's it may not be fuel. More Info and we'll see if we can help you with your issue!
Re: I have a 1999 Crver 356 with dual 440 engines. Under full power there is less than 3500 rpm's. Is that normal?
Posted: February 20th, 2018, 3:17 pm
by bud37
Welcome to the forum.....Also, I guess the simple answer is no......but if you are on salt water, is the bottom clean ?? there is enough drag from that to create your complaint.
Re: I have a 1999 Crver 356 with dual 440 engines. Under full power there is less than 3500 rpm's. Is that normal?
Posted: February 20th, 2018, 10:06 pm
by Viper
Welcome aboard
First we need correct engine info, unless she's been re-powered with older engines, I'm pretty sure you don't have Chrysler 440 engines. Do you have Yanmar diesels?
The rpm on 440 gasers would be higher but pretty sure 3500 is about right for the Yanmars, maybe even a little lower. Would have to confirm but 3300 sounds right.
Re: I have a 1999 Crver 356 with dual 440 engines. Under full power there is less than 3500 rpm's. Is that normal?
Posted: February 20th, 2018, 10:17 pm
by tomschauer
As others have mentioned, please provide more info on your engines. If not sure what you have take pictures and post them.
If they are diesels, 3500 rpm is pushing them hard. If they are gas, 454, 7.4 liter or 502, 8.2 liter they should do 4400 rpms.
Re: I have a 1999 Crver 356 with dual 440 engines. Under full power there is less than 3500 rpm's. Is that normal?
Posted: February 20th, 2018, 10:20 pm
by tomschauer
Also, if you have 440hp diesels at 3500 rpm, that boat should be MOVING pretty fast!!! I would guess 34-35 mph. If you are getting that you are doing great!
Re: I have a 1999 Crver 356 with dual 440 engines. Under full power there is less than 3500 rpm's. Is that normal?
Posted: February 22nd, 2018, 11:16 am
by buster53
Doesn't Cummins make a 440? Lot of engine for a 356.
Edit...
It just dawned on me, this is the gas engines forum. Being a '99, I'm guessing the OP has 454's.
If they are 454's, 3300 is way low.
Biggest culprits:
Bottom growth - barnacles
Wrong propellers
engine not running good.
My money is on #1, maybe #2