How much does my boat weigh?

birdman23

Cadet
Joined
Mar 22, 2008
Messages
14
I have a 1986 bayliner capri 1800 with a force 125hp on it. how much does it weigh? how fast can i expect to go in it?

thanks
 

zibzer

Petty Officer 2nd Class
Joined
Apr 28, 2007
Messages
114
Re: How much does my boat weigh?

what is WOT?

Wound out trhottle?

he's just messing with you.

WOT= Wide Open Throttle. ..

Your best bet is to use a truck scale. Or gravel yard or something and ask them to weigh your truck with and without the boat. then subtract one number from the other and viola. your boat weight (plus trailer)

Your boat has a Net Weight 1470Lbs (i dont think that includes motor.. but motor weighs around 300lbs)

With all the equipment and you I would guess between 1800-2100
 

180shabah

Rear Admiral
Joined
Mar 26, 2005
Messages
4,995
Re: How much does my boat weigh?

he's just messing with you.

NOPE, I was serious. We are talking about a 23 year old boat. We can estimate the weight when it was new, but it has most likely picked up a few pounds in water retention, Plus the engine is probably no longer making the full 125hp. The engine may or may not be set at the correct hight. It may or may not have the correct prop on it. etc.........

A truck scale and a WOT test is the only way to get real data.


What is WOT? Wide Open Throttle

Why is it important? Unlike a car, your boat only has one gear so we use the propellor to "adjust" the RPM's. Every marine engine has a WOT rating, or range of RPM's that is acceptable at WOT. On my engine the range is 4400-4800, yours will be different but the idea is the same. If pitch of a prop is too low, then the engine will be capable of exceding the upper limit and you risk the engine litteraly flying apart. If the prop pitch is too high, then the engine will not be capable of reaching the lower limit. This puts incredible strain on the engine and can result in bearing and valve damage. In either case performance and economy are both altered.

How do you perform a WOT test. Load the boat normally, this includes any gear, coolers and passengers tht will USUALLY be aboard. Get the boat on plane in clear water with plenty of room and open the throttle all the way. Adjust the motor trim for maximum speed (use a GPS if possible the dash speedo is not accurate))and RPM. Note both and compare the RPM's to the range given by your engine manufacturer. The first time you do this be cautious, over-reving and blowing a motor will ruin your day.
 

zibzer

Petty Officer 2nd Class
Joined
Apr 28, 2007
Messages
114
Re: How much does my boat weigh?

NOPE, I was serious. We are talking about a 23 year old boat. We can estimate the weight when it was new, but it has most likely picked up a few pounds in water retention, Plus the engine is probably no longer making the full 125hp. The engine may or may not be set at the correct hight. It may or may not have the correct prop on it. etc.........

A truck scale and a WOT test is the only way to get real data.


What is WOT? Wide Open Throttle

Why is it important? Unlike a car, your boat only has one gear so we use the propellor to "adjust" the RPM's. Every marine engine has a WOT rating, or range of RPM's that is acceptable at WOT. On my engine the range is 4400-4800, yours will be different but the idea is the same. If pitch of a prop is too low, then the engine will be capable of exceding the upper limit and you risk the engine litteraly flying apart. If the prop pitch is too high, then the engine will not be capable of reaching the lower limit. This puts incredible strain on the engine and can result in bearing and valve damage. In either case performance and economy are both altered.

How do you perform a WOT test. Load the boat normally, this includes any gear, coolers and passengers tht will USUALLY be aboard. Get the boat on plane in clear water with plenty of room and open the throttle all the way. Adjust the motor trim for maximum speed (use a GPS if possible the dash speedo is not accurate))and RPM. Note both and compare the RPM's to the range given by your engine manufacturer. The first time you do this be cautious, over-reving and blowing a motor will ruin your day.

My bad, thanks for clarifying. It sounded to me you were asking to do a WOT test on the truck scale. I dont know why I though that.
 

QC

Supreme Mariner
Joined
Mar 22, 2005
Messages
22,783
Re: How much does my boat weigh?

Your WOT throttle range for the Force 125 is 4250 - 5250. If you fall in the higher end you will have more flexibility and better hole shot (acceleration). If you fall in the lower end of the range you will probably (not always) have both better fuel economy and higher top speed, but probable poor hole shot.

BTW, I think that 1470 lbs probably included the engine, but no gear, fuel etc. Most 18 ft. and under bare hulls are sub 1000 lbs . . .

My guess is mid 40's for speed if it is propped right and running right. High 30's would not be a major dissapointment due to the things that 180 points out . . .
 
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