Should I do it
 

Currently I have a 1987 20' SF with a mariner 200. Last weekend the motor gave up so it's time for a new one.

I've looked around and can't find anything but I talked to my yamaha dealer who has a great deal on a 225 ox66. My current engine weights 400lbs and the ox66 would be tipping the scales at just under 500lbs. I would really rather get something lighter but I can't find anything as cheap as this engine. I really can't find any other engine for that matter and I'm itching to get back on the water.

I've sat on my engine when I was parked at the dock (total weight of me plus engine is ~570). With no one in the back it will still self bail. But barely. With 1 person in the back water will come in the scuppers. I always trailer and usually have the scuppers plugged anyway becuase with my current setup water will come in with 2 people fish the back.

What would you guys do?

Presumably you have a 25" transom, but I think 500lbs motor on a 20 is bad juju.:eek:

Close your transom or stay out of the big pool. Clearly you're hellbent on top speed. In that case get an old 2.4L merc (360 lbs) and put some 225 carbs on it. With gas moving near $5/gal, depending on your budget and use, I'd seriously consider a 140 Zuke or a 115 - 150 etec or optimax or even a 4S Yamaha F115.

my .02

Listen to the Google Earth Mastah.

My rude 150 is good on power and weight is the enemy on these slackers.

Light is right. Wanna go fast, get a Merc. Simple. Just keep it light.

Cheers,
NSF

I honestly am not concerned about speed. I usually cruise 25-30. I almost never go over 40. This is the only engine I can find at the moment. I'm just itching to get back on the water. I would love a 115 Yamaha but can't afford it.

I can get this 1998 ox66 225 for $2000 with rigging.

Where are you located Yz? That price is good especially with rigging, but again weight a the factor. Shipping a motor is really pretty cheap and now knowing top end ain't your primary issue, I'd suggest you look around on scream and fly or craigslist for something lighter. You can find reliable 115 to 150 hp 2 strokes all day long for well under that 2K price. Good luck.

Im located in nantucket, mass. (which makes finding an engine that much more difficult becasue im on an island)

Idealy if money wasnt an issue i would get a new yamaha f115 but unfortunately it is very much out of my price range. ill take a look at scream and fly didnt think of that. Although if im going through the trouble of a repower i would like to switch to yamaha, but at this point ill take almost any running engine

You might try to get in touch with Bigshrimpin via private message. He might just have a Franken Merc or Mariner for sale or perhaps the parts you need. The guy is a master with Mercs and Johnnyrudes. and he knows his way around motor salvage. He's probably really busy slammin' grumpy stripers right now but he's down near Woods Hole and fishes E rocks and Buzzards's. If you can connect, surely you could catch a ferry to pick up a motor on the Cape. Bunch of guys on the south end of the cape that might be willin' to help you out. Good luck. By the way I run a 83 Merc 115 inline six and is pushes my Seafari at 25-30 all day getting about 2.5mpg. Knowing you're on Nantucket reinforces the need for a light engine. And good bilge pumps, and a transom wall. Mitchman lost his 20 off Martha's Vineyard last year. Sunk in minutes because his pumps failed. Do a search for his bro's video. Spooky but they all made it home.

i remember seeing the video last year on thehulltruth, it went down quick. I actually just got a second bilge pump and high water switch this year, now i just need to get the boat wet. thanks for the advice and ill try some pm's

Check you private mail in a few minutes. There is also a 2.5L 175 in worcester for a bit more than your plan but hey its negotiable ... Good Luck,
Gillie

Gillie has a great suggestion contacting Bigshrimpin. Also try some of the marinas along the south side of the Cape, particularly Dennis to Chatham. Lots of boats around there and lots of guys fishing commercial so older 2 strokes are readily available. A lot of the Chatham guys swear by the older Yamahas (2.6-3.3L) so keep that in mind. Just make sure that shift shaft has already been replaced before snatching one up or you could be in for a bitch of a repair. Also check CL...I've seen numerous 115's (all makes) available recently. As a lot of SC owners have already figured out, the 130 Yammie is almost a perfect match for the 20 so try to find one of those.

As others have said, that OX66 is a lot of weight hanging off an open transom. Even on the back of my dad's former 23' Sceptre, his 25" carb'd 225 would cause water over the transom with a couple guys in the back.

i have a 115 2 stroke mariner on my 20 fter and i usally cruise at 25 mph. it will go faster but with the fuel prices and all. i'm also in mass and do alot of fishing around the vinyard. i'll keep my eye out for something for you. moved my battery to the bow to lesson some of the weight in the back this spring. like the guys say on thr site. the less weight aft , the better the boat cruises. i don't like the water coming threw the rear scuppers and leaking threw the wire hole and into the bildge either. this may help.

mercury is the way to go if you can find one, i have a 94 200XRI with 2003 power head, lots of power at 395 lbs. gas thirsty but shes got power bottom, middle and top!

Although self-bailing at the dock is an obvious issue with a 500 lb motor, it's not the most important IMHO. The OPTIMUM motor weight for the 19-20' hulls is around 300 lbs because that's what they were DESIGNED FOR! As you increase motor weight above 300 lbs, your min planing will increase from around 12-13 mph up to the low 20's and the ride will get worse! You can offset some of that adverse CG shift by moving batteries, consoles and gas tanks, but the boat performs much better overall with a lighter motor. I'm speaking as a guy who's "been there, done that"! I ran my boat for over 30 years with a 300 lb V-4 and it handled great in all sorts of conditions. When I repowered, I increased motor weight by about 130 lbs AND added a bracket with 30" setback, both of which significantly shifted CG, with significant negative impacts on min planing speed and ride! Self bailing at dock is still acceptable because of the big flotation tank on the Hermco bracket (I would NEVER install a NON-FLOTATION bracket like a Stainless Marine or a Porta on a 20!) With the help of a 4B stern lifting prop and a fin, I finally got ride and handling back to about what it was, but it took a lot of tweaking!

Bottom line, the boat will perform best with a lightweight 2-stroke. As others have suggested, a Yamaha 2S V-4, an old Black Max Merc V-6, or a mid-90's OMC 60 degree V-6 all have good power/weight ratios and would work well. Send a PM to Big Shrimpin . . . I'm sure he can fix you up or help you find a good deal on a motor.

you might find a nice fresh drop on powerhead at scream & fly - I can get you references from there on the seller - Frank Mole Transport over there runs the whole east coast and could throw a motor or powerhead in his truck easy, he's based up there

Power for a classic 20'
 

I really appreciate this thread. Like my man Teasem I like to to be able to go home when it's time to go home. I use to run south out of Angel Fish Creek (Northern Key Largo)We sometimes would end up 20-50 miles to the east or maybe south so coming home was usually trying to beat the sunset. Here in Central Florida I have fished from Steinehatchee to Tampa Bay and I'm still the same way; "Let's go find some fish" and I continually end up 2 hour's from the boat ramp. This new 20 footer project will be fun and getting to the end result is the fun part. So I'm all ears when I read about powering these classic 20cc's.
I can really appreciate the effect of how the center of gravity will effect a boat's performance and attitude. So what really can you expect with running a later model 6 cylinder verses a 4 cylinder? What I had thought up to today was that the hull would be okay as long as the motor weighed as close to "400lbs" as possible; and one of the the ultimate motors of choice is the DF140 weighing a tad bit more. I figured the 150 would get the boat to the mid to upper 40's and a 175 maybe 50/51 a 200 low to mid 50's. The 4 cylinder's maybe upper 30's. but great fuel economy. Of course I agree completely your only going to go as fast and safe as the sea allows you; thoroughly understood! So the question is; with a full transom and some sort of floatation bracket, the batteries up front, a standard 49 gallon fuel tank slid forward, a livewell under a leaning post, a raised deck and scuppers out the back, What is the ideal motor?
Like Dave I enjoy re-inventing the wheel and trying to acheive the perfect or best balance for the hull and my specific needs. For me it's a livewell full of frisky bait in the am. and a cooler full of dead fish in the pm. I need rod holders a good bottom machine/gps and good tunes.
When I was a "wee lad" in the early 70's and these 20's started showing up they were the ultimate fishing machine. The best of the best fished out of them. Heck in 1972 I think all they had was a 3 or 4 cylinder outboard; my dad replaced a '68 100 horse Evinrude with a new 125 Johnson on a 18' Thunderbird and it was huge! All the larger boat's ran I/O's or inboard's. From that point forward the outboards grew bigger every year and in 1981 I had my own 235 Evinrude on my boat.
So please chime in. What motor do you have on your 20 ft Sea Craft? does it porpoise, do you have trim tab's? does it self bail? how fast does it run? how many gallons do you burn doing what you do? Are you happy with it's performance or how would you improve it?
The ultimate goal is to share the vast array of knowledge here and improve and modernize these classics so they'll be around another 40 years from now.

Thanks' Wild Bill

I have a 375lb Mercury Optimax 90hp. I have the Seafari 20, so I have more weight forward than the CC. WOT with normal load is 33-34. Cruise is 22-24 mph at 5.3 to 5.7 mpg.
I had tremendous problems with ethanol with this motor (12K in warranty repairs), but no problems since I stopped using blended gas.

Thank you for everyone's input. I decided against the ox66. Turns out the marina also had a 2007 f115 with 34 hours so chances are in going that route. The 115 weights about 15 lbs more then my current motor but the fact it's a newer 4s and I know it's history will put my mind at ease when out fishing. I've never fully trusted the mariner and I've got a yammie 4s on my other boat and love it.