35 mph

S

steplift20

God
does that sound right to you
v20 steplift with a 150 merc O.B. turnig a 15x17 aluminum prop
35mph @ W,O,T
if i switched to a s,s, prop how much more should i get in mph
 
I am running a johnson 150 with a 15x17 SS prop. WOT fully loaded is around 39-40mph, light load and trimmed up I can hit 45. If you are 35 fully loaded then I think you are pretty good, but if that is trimmed up and light you may want to have the prop refinished.

-Svence
 
I still haven't taken the time to get mine dialed in right.
First prop was a 14x19 stainless, it turned 5100rpm & 42mph, this was a light load in the boat, 20gal fuel and smooth water.
The second prop was a 14.8x17 aluminum, it turned 5000rpm & 41 mph normal load in the boat for 2 people fishing , 40gal fuel and rough choppy water.
 
Sounds like you got your RPM's confused. Normally your RPM's will change @500 RPM's between prop pitches. And If the diameter is the same, you will turn @200 rpm's less changing from an alluminum to a stainless. Maybe this will help.
 
Jetty Rocker said:
Sounds like you got your RPM's confused. Normally your RPM's will change @500 RPM's between prop pitches. And If the diameter is the same, you will turn @200 rpm's less changing from an alluminum to a stainless. Maybe this will help.
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The new aluminum series for the OMC engines work like stainless props do for the most part. I ran a 19 VIPIR on my bowrider which would run 47-48 loaded down and turn 5600 RPM's. I then tried one of the newer large diameter aluminums that turned 5400 RPM's and ran 45-46 MPH. The diameter as well as blade design plays a large role in propping. I would think the APOLLO 4 blade in a 16 or 18 pitch would work really well on a V-20 for lower HP numbers. A large diameter like a MIRAGE would work well too probably, but I don't think a V-20 is really heavy enough to really need a 15"-15 1/2" prop.
 
I carry a lot of weight in my boats, when I had the V20 it would be 2 or 3 guys 60 gal gas, and all gear.
I liked the 15 x 15 1/4 prop, got out the hole fast and still manged mid 30's for speed.

Cuddy
 
W.O.T is 5800 rpms
is it a light load? not sure 2 adults 35 gallons of fuel
food,ice,fish it gets heavy, shucks my tackle bag weights about 30lbs
 
steplift20 said:
W.O.T is 5800 rpms
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This sounds like part of your problem. If that is a 2.0L 5800 isn't horrible, but 5500-5600 would be ALOT better. And if you have a 2.5L you need to get the RPM's down to around 5300-5500. Around 5600 the porting in a 150 MERC is pretty well out of air, they just don't run much above 5600 stock. I'm guessing since you say you have a 150, and a 17 pitch you have a 2.0L though. Try a STAINLESS prop in a 17-19 pitch range. If your after cruise and economy go with a large diameter or a 4 blade, and if your after top end go with a 14-14 1/4" 3 blade stainless.
 
THEFERMANATOR said:
This sounds like part of your problem. If that is a 2.0L 5800 isn't horrible, but 5500-5600 would be ALOT better. And if you have a 2.5L you need to get the RPM's down to around 5300-5500. Around 5600 the porting in a 150 MERC is pretty well out of air, they just don't run much above 5600 stock. I'm guessing since you say you have a 150, and a 17 pitch you have a 2.0L though. Try a STAINLESS prop in a 17-19 pitch range. If your after cruise and economy go with a large diameter or a 4 blade, and if your after top end go with a 14-14 1/4" 3 blade stainless.
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I thought Mercs run around the 6000 range. I've got a 2.5L 200hp Merc. and my mech says they should run in the 5600-6100 wot. My aluminum prop is so old and crusty that I can't tell what size it is any more, but with my curtains up and half tank of fuel, I can average 42 in a two way run. Without the curtains I can get 45-46. Given that's on a flat day with probably only one blade ever touching the water b/c of being trimmed up so much.
 
high rpm works good on light boats, especially if the engine has been modified, for heavy boats like the v, proping the mercs out to the 5300-5500 works out pretty good. try a 17p Mirage plus, it has very low slippage, doesn't need a lot of trim, and works well on heavier boats
 
The 200 MERCS were 5800 WOT stock, and the 150/175's were 5500. I know my 150 XRI I had would fall flat on it's face at 5600, even jacking the jack plate up and letting it blow out would barely get more than 5600. The 200's had ALOT different porting and the different front case half that helped up high in the RPM's.
 
I keep forgeting we are talking baout a 150, I remeber how small the exhaust outlet is in the mid section of the smaller motors. Had a freind that built a 200, could never get it to run like he thought it should, took the power head off and discovered he had a 135/150 mid, we replaced it with a 200 mid, it ran like it was supposed to tehn. I still thin k tht 17 Mirage pluss would be a good prop, it will probably pull the rpms down to at least 5400
 
spareparts said:
I keep forgeting we are talking baout a 150, I remeber how small the exhaust outlet is in the mid section of the smaller motors. Had a freind that built a 200, could never get it to run like he thought it should, took the power head off and discovered he had a 135/150 mid, we replaced it with a 200 mid, it ran like it was supposed to tehn. I still thin k tht 17 Mirage pluss would be a good prop, it will probably pull the rpms down to at least 5400
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A 17 MIRAGE would proably work REALLY good for economy and cruising. He may even need a 19 if he has a 2.0L with the 2:1 lower unit. I just bought the MICHIGAN WHEEL equivelant off of EBAY for $150 shipped. The MIRAGES pop up on there for $125-150 on occasion in nice condition.
 
I've ha real good luck with the Mirage plus, on general purpose heavier boats, they work real good, the original mirage is a little too much for an outboard, thet work real good on big engine I/O's. We hada guy spinning a 27p original mirage 5200 rpm thur a 1.32 ratio, it ouwl get just above the century mark on the land& Sea speedo, he sent it to Mercury and had it lab finished, slowed it down 7 mph, bought another stock wheel, picked it right back up
 
For me a 17p Rev 4 is the perfect prop on my 87 V w/ an 88' 2.0 l 150 Merc on the back. She turns 5500 with virtually any load. She's mounted 1 hole from the top and I find that to be the perfect height for this motor / prop / boat combo.
 
The REV 4 is a good prop, and many have said the new ENERTIA works REALLY well on boats in this size range. I only mention the MIRAGE style because they can be had for VERY reasoneable money if you watch EBAY and CRAIGSLIST. And the large diameter really helps to get your cruising speed up there, and it holds the water with a death grip.
 
I carry a lot of weight in my boats, when I had the V20 it would be 2 or 3 guys 60 gal gas, and all gear.
I liked the 15 x 15 1/4 prop, got out the hole fast and still manged mid 30's for speed.
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Plus, whent the boat fills up with water the lower pitched prop will still dig you out - right MJ?!? :zip:
 
You definitely have a 2.0L with those numbers. Try raising the motor a few holes up, you might pick up a few MPH. 35mph for a 2.0L . . . is not too far off.
 
Spare's right on on the Mirage prop...mine got 42 mph @ 6,000 rpms w/a 17 x 15.5 Mirage...had to go w/a 17 x 15.25 Power Tech on my Honda, but the Mirage oughtta do GREAT on yer Merc...
 
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