Repowering 86 Aquasport 200 Osprey

[JayMac476]

I am in the process of restoring my 86 Aquasport 200 Osprey. The boat came with a great running 86 Evinrude 115 but is just not enough power to get up and go and top speed at WOT is only 29 mph. I am thinking about putting an Armstrong bracket on it and installing a mis 90's Evinrude 150. Any thoughts?

[dburr]

What kind of speed are you looking for and what will be the intended use of the boat?

[FJStretch]

I just purchased a 1986 Osprey 200 with a 1997 Zuk 150 2-stroke last week. So i guess that makes us related or something (grin). During the sea trial, the Raytheon Fish Finder indicated the boat was doing 52 mph. Although it seemed to be fast, I am not yet convinced we were moving that fast. I' doing some general repairs and sprucing things up but I'm hoping to get on the water this weekend.  I will use my iPhone gps app to see how fast the boat really is and I will let you know.

[JayMac476]

I went scalloping a few weeks ago with my buddy who I followed on the way out of the tricky channels in homosassa. He has a 20 foot seacraft with a 150 Suzuki 4 stroke.his boat had more weight and gear on it then mine and I couldn't even come close to keeping pace with him. His boat will top out at 45 which seems a bit 2 fast for me. I'd like to get it around 35-37 with some gear and one other person on board. My biggest problem though is getting it on plane. Seems to take forever something like 60-70 seconds. I just had carbs rebuilt on it and a new 21 pitch stainless prop

[Georgie]

JayMac-

60-70 seconds?!?!    I don't even have enough patience to wait that long.  In all seriousness 10 seconds is too long to wait for a boat to get on plane.  Almost 110% positive your prop pitch is WAYYYY too much for the lil crossflow on your Osprey 20.   You should likely be in the 17 pitch range, possibly even lower to not overload the engine on a boat that size.  What is the max RPM you're seeing at full throttle? Should be in the 5500 rpm range, and I'm gonna guess you're quite a bit lower.  Regardless, the 115 is not quite enough power for the 20, and the 150HP range would be a much better fit.  That said, using the armstrong bracket might put the extra heft of a V6 150 a bit too far aft and compromise the balance of the whole boat....Aqua's are relatively sensitive since they're pretty light boats by design.  Read through the posts in the prop thread under the engines and electronics topic.  There's some real good info there that might help you make some decisions.  

Unless cash flow is not an issue, you might also want to try tweaking your 115 a bit.  If  you're mechanically inclined you can change some relatively minor exhaust and carb parts to gain a few horses if you're interested.  OMC made the V4 crossflow from 88HP to 140HP and carb/exhaust differences pretty much accounted for the entire range of power.  A LOT less $$ than a new engine if you can do the work yourself.

[fitz73222]

I'm thinking a 15 pitch will wake this rig up. The powerhead mods to get more horsepower out of the 115 would also include a complete teardown and porting job which really doesn't make a lot of sense for a 1986 engine.The main difference between OMC 99 cu. in V4's was the intake and exhaust port sizes and the addition of the exhaust "pot belly" tuner. Later models regardless of horsepower had the pot belly tuner but smaller or larger ports to make horsepower and torque. Other than some jet and timing changes the blocks were virtually identical. The premise is pretty simple, more air and fuel in, more air and fuel out and the ports control this. I've seen a lot of 20 Ospreys rigged with a "base" 115 and I'm thinking the performance was better than what your presently getting. My old 73 22-2 with twin 115's will run 31 mph at WOT on one engine with 4 people and 50 gallons of fuel with a 4 blade 18 pitch @4850 rpm and cruise at 23 mph at 3700. I would do a compression test on your engine to make sure there isn't any problems and then look into a different prop.

[Blue Agave]

IMO I believe a 150 hp motor is perfect for the boat. As far as the Armstrong bracket goes, I have one on my 19'6" and I love it. My boat was a full rebuild so I was able to shift weight forward to offset the the bracket setback.

Regarding your buddies SeaCraft, that's a faster hull. Even with the same hp the aquasport will not be as fast.

Good luck with your decision.

[FJStretch]

Hi folks,

I have an Osprey 200 with a 1997 Zuk 150 2-stroke. She will do 50+ mph easily. Gets right up on plane quickly. I just got her about a month ago and I don't know what the prop pitch is... But it is doing me right.

Respect to Georgie.... His read on the RPMs is dead-on correct as far as I can tell. I am right around 5500 RPMs at WOT.

[CTsalt12]

50 mph good lord.  I am good with going 35 on my little boat and even that seems fast

[FJStretch]

I agree with you CTsalt12!
Yesterday, I sheared-off the bolt that attaches the steering arm to the steering cylinder mount --- immediately losing control of the motor/rudder. Luckily, I was only idling back to the ramp when it happened. Glad I wasn't going fast when the bolt failed. Sharp and sudden turns at high speed are not advised!

I hope this is a story the speed-demons will consider. You never know when something bad might happen.... and when it does, slower is better than fast.

[Capt Matt]

50 mph plus hydraulic steering time
Glad it happened at idle
Capt Matt

[Aswaff400]

my 200 osprey with a light load would run mid 50's with a 200 evinrude. fully loaded with 2 guys, full fuel, full livewell she run 50-51 mph. and cruise 30 mph at 3500 rpm.

[JayMac476]

The boat came with a 21 pitch prop that was brand new. Thanks for all the replys. I will run out and try a smaller pitch on the prop.

[200CCPMerc200]

The boat came with a 21 pitch prop that was brand new. Thanks for all the replys. I will run out and try a smaller pitch on the prop.

Way smaller pitch, your talkin 200-225 hp motor turning that on say a 200ccp

[JayMac476]

I went with a 17 pitch prop and it made a big difference when getting up on plane. Still with 3 adults and gear on board it's just not enough motor especially if I have to slow down and try to speed up again. With just me on the boat it flys so I will be repowering this winter to a 150. I just hope it doesn't change the waterline to much at the back of the boat. Right now it's just below the self bailing holes in the hull.