Repowering old sprints

[Braddaddy]

Good afternoon fellow Sprint Boat enthusiasts! I have a 2000 Sprint 221 DC tournament and I'm considering repowering it with a new 4 stroke. The hull has an unlimited power rating but I wonder if the transom can support today's heavier 4 stroke outboards like a 250ss suzuki or 250 merc? It currently has a 200efi on it. Runs okay but needs a bit more power imo.

[Bassmeister]

Welcome aboard ! With the unlimited rating I can see no reason for worry....that said the new Merc or Yammies are boasting lighter weights or almost as light as a same hp two stroke. I don't know the weight of the Suzuki. All engines I'm speaking of are the 250 hp range. Myself I'm running a 250 Evinrude with 8" setback on a 207 Pro with no issues. The 207 is rated for 225 max. The best thing I did for hole shot was changing to the Bravo fs props. Others have run bigger engines without issues being spoken of here. The Rude weighs in @ 509 Lbs. Hopefully others will chime in with their stories. I would have loved to find a sweet 221 when I got mine.

[Braddaddy]

Thanks for the response, I wouldn't exactly call my 221 "sweet" but I'm working on her. From what I've been told and read, the new 4 strokes weigh about 100lbs more than a comparable 2 stroke, just wanted to make sure the transom could support the extra weight. My 200 efi is on a 12" setback with a 26 pitch trophy plus. Hole shot is pretty rough with a full load and it runs out around 65, I personally think it's over propped but I haven't had the opportunity to mess with it much.

[Bassmeister]

I'd think the 200 would be better served with a 24 p prop. But we would need more info....prop to pad , rpms while getting on plane and wot rpms....

[Braddaddy]

Prop to pad is about 3 1/2". I raised the plate up until I started to lose water pressure and got some steering torque so I dropped it back down just enough to steady out the water pressure. I saw no increase or decrease in performance or RPM. WOT is about 5700 at 65mph, heavily loaded with 2 people it's about 5500 at 63mph. I agree with the pitch, maybe a 25 pitch tempest or 24 pitch fury but I can tinker with that off and on. My biggest concern was the ability of the old sprint to support a new 625lb 4 stroke hanging off the back if I decided to do it.

[CB_SabreFTD18]

I had the exact same year model and small block EFI. 2 props it liked were 24 Laser2 and 26 A40 Trophy (thin blade/small vent holes). No ring on the Trophy. I just ran it “all natural.” It wouldn’t turn a 25 Tempest Plus. It ran 70 with the Laser solo 1/2 fuel. 71 with the Trophy 1/2 fuel. Zero chine with the Trophy. Repowered in 2005 with a new in box ‘03 250 EFI Yamaha. Motor was heavy. Out of break in, it hit 6000 at 73 with the Trophy. Had the Trophy repitched to 28 B&B. Ran 75 with zero chine 1/2 fuel. Bought a 27 T1 thinking it was 80 mph boat. 76 was all I could get out of it. Ran 74.5 with 2 people at take off. New 4 strokes weigh similar to that 250 EFI Yamaha if I recall. The hull weight on that 221 DC was around 1500 lbs, I think. Great boat it was. Wish I still had it.
Call a good prop guy and ask about thinning down your Trophy to replicate that old school A40 I had. Someone out there has a 26 collecting dust too.

[Braddaddy]

Thanks for the info. I may try a couple of different props and see what happens. I'm not against keeping the old 2 stroke, it smokes and loves gas but runs good. I don't expect 75mph but I think 67-70 with a decent hole shot isn't outside of the realm of possibilities.

[Bassmeister]

On the 221 I don't see the numbers you're looking at with the 200....you're already @ 5700 with your present prop....With your set up 65 is about right .....The Suk may weigh that much but the Merc and Yammies are advertising less weight.... JMHO.

[Braddaddy]

I can't say I disagree. She's a big girl so 65 is fine with me. Still like the idea of a 4 stroke though. Or maybe a 300 opti proxs lol.