WOT, 4500 rpm?? v-pro 200

[cdsonsini]

I have a new to me Yamaha v-pro 200 on a 23' cc, with an 8" jack plate. At WOT It is only running at 4500-4800 rpm @ 45-48mph gps. That is with the jack plate all the way down and the motor trimmed all the way down as well. Any Ideas??

 

[Reel Kahuna]

Re: WOT, 4500 rpm?? v-pro 200

What's the prop pitch? I put a Pro V 150 that had a 20" pitch on my 20' that only got 3K rpm. I bought a 17" pitch got the WOT to 4900-5100 rpm. Factory is 5600 rpm at WOT so today I exchanged the prop to a 15" and hopefully will get the rpm to 5600.

 

[cdsonsini]

Re: WOT, 4500 rpm?? v-pro 200

Its a merc 23p prop.

 

[99yam40]

Re: WOT, 4500 rpm?? v-pro 200

http://www.yamaha-motor.com/outboard/products/perfbull.aspx

 

[rodbolt]

Re: WOT, 4500 rpm?? v-pro 200

use test wheel YB-1626, engine must be able to spin it 5300 to 5500 RPM.
if it can try trimming and jacking and possibly a prop swap.
if it cannot FIX the engine.
the test wheel is the only way,other than a dyno run, to ascertain engine issues from prop and hull issues.

kahuna, you need to do the same thing with the same test wheel looking for 4900 to 5100 RPM.
my f150 with a 13.75x18 on a 21 seapro with a second station will spin 5700 all day long.
you either have a very heavy boat or a sick motor.

 

[cdsonsini]

Re: WOT, 4500 rpm?? v-pro 200

Sorry Rodbolt, not familiar with the test wheel method. Please elaborate.

 

[rodbolt]

Re: WOT, 4500 rpm?? v-pro 200

the test wheel is kinda like a prop that installs inplace of the prop but provides a load with no thrust.
its made now by K and L tools for yamaha.
it places a known load on the engine and yamaha publishes the RPM various engines should turn with the proper test wheel.
to test, remove prop,using the prop attaching hardware install test wheel. back it down the ramp or a very large tank,submerge the gearcase and about 1\2 of the midsection.
start engine and allow to warm up.
place in gear,go WOT,observe tachometer or use a known good shop tach.
it either turns the reccomended RPM or its sick.
no amount of propping a sick engine will help a sick engine.

 

[Reel Kahuna]

Re: WOT, 4500 rpm?? v-pro 200

I swapped out the 17 to a 15 pitch and hit 42mph at 5600rpm WOT. Got up on plane quick and now I"m a happer boater .

I'd suggest you check with your local prop shop to see if they have any used prop for you to test. If not, then ask that if you bought a prop and you still need to go to a lower, would they exchange. My prop shop allowed me an even exchange. Worth a try.

 

[iammarcuse]

Re: WOT, 4500 rpm?? v-pro 200

Its a merc 23p prop.

I would say you are overpropped for that boat. You could try raising your jackplate, but I would try a 19" prop. Should put you right on the money with better holeshot and no loss of speed.

 

[rodbolt]

Re: WOT, 4500 rpm?? v-pro 200

like I say, if all you want is RPM toss the prop overboard.
we still have no clue as to what is or was wrong.
its very possible you simply masked an issue that may come back and bite your wallet.
8" of pitch is gone, for each inch of pitch lost you should have gained 250 to 350 RPM.
8 times 250 is 2000, thats the RPM gain you should have seen.
thats why Yamaha developed this test wheel.
takes the guess work out of seperating hull and rigging issues from engine issues.

 

[iammarcuse]

Re: WOT, 4500 rpm?? v-pro 200

Rodbolt is almost always right (he's the man) but this time he has the two posters confused. Kahuna is running the 15" prop, cdsonsini is running the 23". There was no loss of 8" of pitch. A 23' CC with a 200 is overpropped with a 23" prop. Should be about 19" maybe 21" tops.

 

[rodbolt]

Re: WOT, 4500 rpm?? v-pro 200

see, I am always confused.
its also why normally I wont keep posting when a thread gets hijacked,
point Ill remember.

 

[cdsonsini]

Re: WOT, 4500 rpm?? v-pro 200

I would say you are overpropped for that boat. You could try raising your jackplate, but I would try a 19" prop. Should put you right on the money with better holeshot and no loss of speed.

I admit I am a rookie when it comes to boats, I am wondering how high I need to try and raise the motor, and how much trim do you think I should give it? I have been running the motor at the bottom of the jack plate trimmed all the way down.

 

[iammarcuse]

Re: WOT, 4500 rpm?? v-pro 200

Trimming right in is almost never necessary unless the boat is hard to get up on plane. Many boats will do fine with the engine straight up and down. When it comes to WOT just keep trimming out till the prop starts slipping. You'll hear it. Then just trim in a bit. Most boats will let you trim right out at WOT. You get most revs, best bow lift and most speed.
As for the jackplate, you basically do the same thing. Raise 1/4" till it starts slipping then back down 1/4". However you do have to be careful about not raising so high you lose water pressure and overheat motor.