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Max rpmbs

26ft. wellcraft w/ gm350 5.7 a

26ft. wellcraft w/ gm350 5.7 alpha 1 gen 1. boat will not go over 3200 rpms.but it runs great with 12 people and 150 gallons of gas...is this max rpm ?
 
"You should get 4600-4800 rpm

"You should get 4600-4800 rpm at WOT.
What prop are you running and what max speed do you get?
Does it get up on plane OK?
12 people; wow, that's quite a party.

Rod"
 
"the parties are awesome. i it

"the parties are awesome. i its a high performance 19 hollow in the center, gets out the water really fast, top speed about 41 @ 3200 rpms."
 
I am guessing your tach is out

I am guessing your tach is out of whack. It happens after they are a few years old.
What is the boat weight with fuel?

Rod
 
"im not sure about the weight,

"im not sure about the weight, i bought the boat used and fully restored, painted, gelcoated, and 20 hrs. on motor for 3,900.00 owner did not have manual and its not stated on the title or registration."
 
I am guessing it weighs around

I am guessing it weighs around 4500 lbs or so; which means it should get more like 48 mph with 260 hp.
YOu may be over-propped; although that usually makes hole shot performance really doggy.
Can you borrow a 17" or so to try out?

Rod
 
yes i changed the prop to a ho

yes i changed the prop to a hollow center 17 @ 3100 rpms i was running exactly 30 mph w/ the same amount of people and fuel. Isnt the lower the pitch higher speed maybe slower take off. 17 pitch @ 3100 rpms @ 30 mph max. and 19 pitch @ 3200 @ 40 mph max. it should be the other way around or no?
 
"Something strange about that.

"Something strange about that.
A lower pitch usually gives better take off and lower top speed at higher rpm @ WOT.

I don't know what is wrong. I would check your tach against a known good one, and maybe your speedo as well.

Rod"
 
"yes its very weird, the contr

"yes its very weird, the controls are brand spanking new. and the mph's, im going along with my gps and tach are about 1 to 2 mph off."
 
"Justin:

You are hauling ab


"Justin:

You are hauling about 2,000 to 2,500 lbs. of fuel, partiers and gear; may just be overloaded. JMHO"
 
"Justin, a prop calc shows tha

"Justin, a prop calc shows that if you have a 1.5 ratio outdrive (I think that's likely for your setup) then you aren't getting 41 mph at 3200 rpm with a 19" prop. If the mph is gps verified close, then it's the tach that it wrong. This makes sense because if you were really only 3200 rpm WOT then I think it'd be a total DOG out of the hole and barely get on plane."
 
tmh:

Welcome and nice calsu


tmh:

Welcome and nice calsulation! I thought it was strange that he was traveling @ 40 MPH @ 3200 RPM w/that boat and load.
 
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