New Engine

[JBASS02]

Time to make the big decision... I've been reading and reading and reading about different outboards and have ended up between two brands, Etec (115hp or 150hp) or Yamaha (115hp). I have a couple questions.

Boat setup: '72 20' SF with 25" transom. I freedive/spearfish the channel island off Santa Barbara, CA. It's a ~30 mile crossing to get to the islands, it's rarely calm enough to reach speeds greater than 30mph. I'm more concerned with handling, safety and fuel efficiency than high speeds.

There is a ~30lb difference between the etec 115 and 150 will that be noticeable in handling/low planing speed? How about fuel consumption(ie. bigger engine works less for the same speed). I'm assuming there is a decent difference at high end speed.

What MPG can I expect at cruise from each motor(etec vs yamaha)?

When I look around the harbor everyone has Yamaha outboards which makes me think it will be easier to find a decent mechanic. I've always had two strokes and like that there is less maintenance and fewer moving parts.

In short what would you buy?

Let me know your thoughts.

[DonV]

Easy, 150 eTec. Search "Bushwacker", he has many posts on the performance of his 150 G1 eTec on his 20'er. I had a 4S 150 Yami on my 22' Pathfinder and it did a very nice job, however I like the 2S for the reasons you referenced (even though I just bought a 4S for my SeaCraft). True point on the mechanic issue, but Yamaha and their service $$$$$ are just crazy. Good luck.

[manitunc]

I run a 2004 Evinrude 150 DI (pre-etec) on my 1968 19' with bracket and its the perfect engine. with lenco tabs, I can plane at under 15 mph and run 45mph on top. quick holeshot and 32mph cruise. 4mpg at cruise.

[JohnC]

You are planning to cruise ~ 60 miles round-trip in "rarely calm" water. That's a tall order for a 20' boat by any standard! I would think that the ability to be on plane at low speed (15 mph or less) would be essential. From what I have read here it seems that even with a 90 ETEC you will top out in the upper 30's and cruise on plane as low as 12 mph if you have to. That's important when you are 20 miles from port and the wind starts to blow. I have not been on a 20 with that power but you could do a search on CSC for Terry England's "Marshtackie". He cruises long range with heavy loads with a 90 ETEC, I think he posted his numbers a while back.
If it were me I would choose the lightest motor I could get. Some of the 4-stroke 115's are pretty light; Mercury is 360# or so - not sure about Yamaha. I personally would be looking at the 90HP ETEC to do the kind of trips you are talking about but I understand that it would be below the "critical minimum HP" in the minds of most people. If I were planning to sell at some point in the future I would want to have a 115; more power is appealing to most buyers.
I would expect to cruise above 4mpg with any of the motors mentioned here.

[gofastsandman]

Originally Posted by JohnC

You are planning to cruise ~ 60 miles round-trip in "rarely calm" water. That's a tall order for a 20' boat by any standard! I would think that the ability to be on plane at low speed (15 mph or less) would be essential. From what I have read here it seems that even with a 90 ETEC you will top out in the upper 30's and cruise on plane as low as 12 mph if you have to. That's important when you are 20 miles from port and the wind starts to blow. I have not been on a 20 with that power but you could do a search on CSC for Terry England's "Marshtackie". He cruises long range with heavy loads with a 90 ETEC, I think he posted his numbers a while back.
If it were me I would choose the lightest motor I could get. Some of the 4-stroke 115's are pretty light; Mercury is 360# or so - not sure about Yamaha. I personally would be looking at the 90HP ETEC to do the kind of trips you are talking about but I understand that it would be below the "critical minimum HP" in the minds of most people. If I were planning to sell at some point in the future I would want to have a 115; more power is appealing to most buyers.
I would expect to cruise above 4mpg with any of the motors mentioned here.

Min plane speed of 12 is what you want.
I cant get below 16-18 w 365 lbs on a25 in transom
89 20 sf

[Terry England]

Originally Posted by JBASS02

Time to make the big decision.......

What MPG can I expect at cruise from each motor(etec vs yamaha)?

When I look around the harbor everyone has Yamaha outboards which makes me think it will be easier to find a decent mechanic. I've always had two strokes and like that there is less maintenance and fewer moving parts.

In short what would you buy?

Let me know your thoughts.

Terry’s stats -
So Last Saturday two of us, 80#’s of ice in the fish cooler, 5 tanks, wet suits, dive weights and assorted sh!t. Ran 27 miles offshore to 38’ off of Bayport hunting for some Gag groupers before the season closes. Kinda’ raggity in the morning blowing out of the north 10 or 12, just starting to white cap.
Pushed the boat off the trailer at 7:30 and slid back on at 5:30. Never shut the engine off all day. Showed 71 miles on the plotter. Turned 3400 making 15 knots going out and 4000 making 24 knots coming home. Burned 14 gallons and a pint of oil (set for 50 to 1) An ’06 motor with about 700 hours on it.
Like Long Tall Sally, “she got everything what uncle Ter need”

[Bushwacker]

Originally Posted by JBASS02

Time to make the big decision... I've been reading and reading and reading about different outboards and have ended up between two brands, Etec (115hp or 150hp) or Yamaha (115hp). I have a couple questions.

Boat setup: '72 20' SF with 25" transom. I freedive/spearfish the channel island off Santa Barbara, CA. It's a ~30 mile crossing to get to the islands, it's rarely calm enough to reach speeds greater than 30mph. I'm more concerned with handling, safety and fuel efficiency than high speeds.

There is a ~30lb difference between the etec 115 and 150 will that be noticeable in handling/low planing speed? How about fuel consumption(ie. bigger engine works less for the same speed). I'm assuming there is a decent difference at high end speed.

What MPG can I expect at cruise from each motor(etec vs yamaha)?

When I look around the harbor everyone has Yamaha outboards which makes me think it will be easier to find a decent mechanic. I've always had two strokes and like that there is less maintenance and fewer moving parts.

In short what would you buy?

I’d buy the 90 hp E-TEC which is MUCH lighter than either the V-4 or V-6 and should be enough power to do what you want! The SeaCraft VDH hull is surprisingly efficient and doesn’t need nearly as much power as the fat modern hulls designed for the heavy 4-strokes! You’re right, the V-6 is only about 30 lbs heavier than the V-4, which has the lowest hp/lb of any motor in BRP’s inventory since they added the V-6 lower unit. Terry England runs a 90 on his 19 and a pair of 115’s on his 25 Bertram, so I’d defer to his judgement, as I think he’s had good experience with both. The I-3 doesn’t have the 2-position exhaust valve of the V-4, which likes to run best at 4000+ rpm when the valve is in the high speed position! If you get into rough conditions and have to throttle down to 3000-3500 rpm at about 12 mph, I suspect the I-3 would be happier at those conditions if it’s propped right. The I-3 is probably about 100 hp vs 125 hp at the prop for the V-4. Terry can probably give you good advice on the prop. I’d lean toward a 4B prop, which will give you more stern lift and reduce min planing speed, which will be your single most important performance parameter for the type of running you’ll be doing.

Regarding fuel economy, the 4-stroke will be slightly better at cruise while the E-TEC will be MUCH better running at hull speed when it’s in the stratified charge mode (like 10 mpg!) so the overall difference in fuel burn will not be very large, especially if you spend a lot of time at low speed. The best data I can give you is from my S. Fl. Circumnavigation trip in my Seafari in 2010 with a very heavy cruising load, when I burned 158.5 gallons of gas and about 1.5 gal of oil to run 693 miles across the Okeechobee waterway, Lake O, down the gulf coast to Flamingo, across to Key Largo, and back up the east coast to Palm Beach for an average of 4.4 mpg. This was with a relatively inefficient PowerTec prop that only got about 3.7-3.8 mpg at cruise. I later found a BRP Cyclone prop that easily got over 4.0 mpg at cruise; your SF is at least a couple hundred pounds lighter so should do a bit better. And because they’re much weaker in low and mid-range torque as well as heavier, the 4-strokes may have trouble planing at 12 mph! This definitely seems to be the case on heavier twin engine rigs.

As far as maintenance is concerned, the E-TEC’s are basically very simple motors with some sophisticated but very reliable sensors and electronics and no valves to burn or adjust, so they don’t need much maintenance, plus you can buy the same basic software the dealer has that runs on a Windows laptop that will allow you to do a lot of troubleshooting. However in the 11 years and ~650 hours I owned my E-TEC, I never really had enough problems with it that I needed the software. If you check out www.etecownersgroup.com, you’ll find a very good forum, much like this one, that’s run by some very experienced E-TEC technicians who can answer any questions you might have on operation and maintenance!

[JBASS02]

Thanks for all the advise. Looks like I'll get a 200hp... just joking 90 Etec it is. I finally got all the wood out of my transom today, which means the tear out is complete and time to start rebuilding.

[Bushwacker]

Good choice! Most folks today have never run the 20’ hull with only 300 lbs on the transom, but I ran my Seafari for over 30 years with a 1975 “115” that probably wasn’t much more than 105 hp at the prop, but it rode and handled great! Cruised at 20 kts with a heavy load in 2-3’ square waves all day long at 4500 rpm and 2.8 mpg, with WOT of 34-35 mph. Gas mileage with the E-TEC should be 40-50% better than that! The ride with the bracket and ~420 lbs of motor mounted 30” further aft was noticeably worse until I added some bandaids like an AV plate fin and 4B prop!

I’d still recommend using Costa in the transom and using a 4B prop and/or a fin on the AV plate for even better low speed performance. Good luck with your restoration!

[Beaver]

Please post some performance numbers when you get squared away. I think that 90 is going to work just great. I remember when I first started getting into the Seacrafts seeing a couple of 20s with 90s on them and thinking "That thing must be super underpowered". Now that I have run my 18 with a 90 for the last 6 years and I've seen how little horsepower these hulls need, I can totally see running a 20 with a 90. More than enough power, rides great high and dry and gets good fuel economy. Long live Variable Deadrise !!!