Got a 89' 19ft sunbird with the 4.3 omc and can only get it up to 37mph, thats with a SS 14 1/2 x19p prop thats not in the best shape. Whats the top speed some of you sunbird owners are getting out of your boats?
I just got my 1994, 19' Corsair Bowrider with Johnson 115 outboard. On the second trip out on the nice flat bay I hit 36 MPH. I hope to do a little better with some tuning and maybe a prop refurb or replacement.
I have a 1994 Sunbird Corsair 170, with a 115 Johnson Outboard as well.. I have a beat up 13.2 x 17 aluminum prop (which is pretty beat up). My top speed is about 32 at WOT, but my RPM's are running way to high 6,200. Is your 14 x 17 SS or aluminum? I put a hydrofoil on as well and that helps the boat plane out a lot faster.. Thanks..
Hey guys I think myself and maybe two other people in America have a 1996 sunbird neptune. I say this because well, try finding any info on this boat! Anyway, it's working out great for me and my family, we're having loads of fun tubing, fishing ,and skiing.
On to the question at hand.
I have a Sunbird Neptune 181 dc with a 90 hp Evinrude and a 14x17 aluminum prop. I'm getting 32 mph on my best days and around 28 mph average. Problem is, I'm only getting around 4200-4500 rpm wot depending on the load.
I just found a used stainless steel prop on Ebay in good shape and at a good price and I'm hoping and praying it's just what I need.
The new prop is a 13 3/8 x 12.
Now going with the math I've been reading from all the prop matching articles every degree of pitch results in 150-200 rpm gain/loss. So 5 degrees of pitch loss should equal 750-1000 rpm gain at wot.
I know the prop is a bit smaller diameter but I also understand that the stainless steel should be stronger and therefore result in a little bit less of rpm gain.
I'm looking for better hole shot to give my skiers a better chance of getting out of the water.
I'll try and report back and maybe the other 1 or 2 Sunbird Neptune owners can use this info for comparison!
Well it turns out the prop I ordered on ebay wasn't a 13 3/8 x 12 but a 13 3/8 by 17. That means, supposedly the only difference between my old prop and the new one is 5/8 inch diameter. Well I thought I would give it a go anyhow just to get an idea and wow. Much better hole shot and gained 500 rpms. I also picked up about 2-3 mph, achieved 34 mph on the gps in rough waters. I think i'm going to stick with this prop for a while. Still have a bit of room for improvement but for a $70 ebay stainless steel prop, I'm pretty happy.
+1 My 20.5 ft with it's 5.0L Ford H.O. Cobra got me up to 47mph also without any passengers. Of course my speedo could be grossly off. I would say at least 40mph. It's going to be awhile before I GPS it though.....
1994 Sunbird Corsair 200 open bow (haven't seen many of these around) with the 5.0 Ford. Hit 52 on GPS with two people on board and a quarter tank of gas roughly, but I was overrevving by a little bit according to the tach. Also this is when the boat only had a doghouse over the engine with no upholstery and two captains chairs. It's a little heavier beast now that it has the sundeck, bow cushions, etc.