Repower

[drcoastline]

I have a 1979 20CC with an older 150 Johnson. I am looking to repower. I have been looking at 150 and 135 engines but I have noticed a lot of 115HP motors on the market. Is anybody running a 20 with a 115? How does the boat perform?

[Fr. Frank]

A 115 will power the 20' ok. My grandfather's 20' Seafari came new from the dealer with a Chrysler 105, which really only put out about 95 hp at the prop. It had a top speed of about 27-28 mph, but it got on plane fairly easily. A new 115 4S EFI should push the 20' into the low to mid 30's at WFO, and cruise at 23-25 mph.

My '72 20' Seafari has a '91 150 hp Merc 2S carb model, reman and balanced in '02, with 200 carbs, and dyno'd at 185+ hp at the propshaft. I have a top speed of about 50 mph at 6100 rpm, I cruise at 4000 rpm and about 34 mph. And that's with Slickkote bottom paint I plan to sand and paint the bottom again this summer. Even though its Slickkote, I'm sure I lose a couple of MPH due to the paint. But I leave it in the water twice every year for a 10-14 day stretch.

There's a red 20' Seafari here in the Crystal River area I see from time to time. I think he said it's a '79 model. He's got an 2004 Suzuki 200hp 2S on the back running a PowerTech 4 blade 21P prop. We ran them up one day just for fun in Ozello Bay, and when I was trimmed up and WFO, running at 51 mph on the GPS, he had at least 3 mph more than I did. He claimed he was doing 60 on his speedometer, but I think he was more like 54-55 mph. He has no bottom paint and his hull is clean and buffed. VERY nice boat. It looks almost brand new inside and out. (Mine just looks old and well loved and used.)

I use a PowerTech prop as well. (PowerTech Propellors) I run a one-of-a-kind custom-built 15.5" diameter by 16.5"P progressive rake 3 blade made by the same company. The blades are very heavy, and I have less than 1/4" clearance between the tips and the cavitation plate. The extra diameter combined with lower pitch and progressive rake change gives me the hole shot and low-mid speed torque application I want at the sacrifice of a little top speed.

[oldbluesplayer]

I've got a 20' Seafari, with an old 83 V4 Johnson 115, 2S carbed - WFO I get about 31 mph / GPS, trimmed, in calm water. The hole shot is good, comes right up on plane, cruises nicely about 24 mph/ gps.

On a 20" transom cutout, the old V4 JohnyRude is a good weight match for the boat.

Would love to try a 140 hp V4, or a Merc 150 like the padre's. New engines, I'd look at a 130 Yam, or a 135 Optimax.

Bill

[eggsuckindog]

I think you would be happier with 150 HP, it would enhance resale as well. We hada white 20 for sale on here and the reason it didn't go quick was it was under powered, in my opinion.

[Fr. Frank]

I agree with ESD, you'd be happier with a 150. Ed's Marine Superstore has a new VMax 150 20" for $7500. Best price I've seen. See it Here

[drcoastline]

Thanks for the opinions. I guess I'll forget the 115's and keep looking at the 135, 140, 150's. My motor is an 89 and pushes the boat along at about 30MPH and 33MPH with a tail wind which is just fine. I am not looking to captain a rocketship I just don't want to be at the helm of a barge. I am mostly thinking about dependability and fuel economy. Assuming I stay with a 2S any opinions on fuel consumption between the 135, 140, 150's? Is it enough to consider or is the decreased horsepower going to cost more to push the boat? Lastly, the 89 generaly runs well. Last year I repalced the powerpacks and shortly thereafter one of the headgaskets went. That's when I got disguted and put the boat away for the rest of the summer. Is it worth rebuilding a motor this old?

[eggsuckindog]

Fuel will be no issue, the new motors are so much better than yours- like 3 times better, you actually won't believe how little your using.

[VirginIslander]

Thanks for the opinions. I guess I'll forget the 115's and keep looking at the 135, 140, 150's. My motor is an 89 and pushes the boat along at about 30MPH and 33MPH with a tail wind which is just fine. I am not looking to captain a rocketship I just don't want to be at the helm of a barge. I am mostly thinking about dependability and fuel economy. Assuming I stay with a 2S any opinions on fuel consumption between the 135, 140, 150's? Is it enough to consider or is the decreased horsepower going to cost more to push the boat? Lastly, the 89 generaly runs well. Last year I repalced the powerpacks and shortly thereafter one of the headgaskets went. That's when I got disguted and put the boat away for the rest of the summer. Is it worth rebuilding a motor this old?

Since it generally runs well, I'd be reluctant to write it off too quickly.

Whether it's worth rebuilding depends a lot on how much of the work you can do yourself, as opposed to having a mechanic do it all, and how much (if any) additional damage was done from the blown head gasket leaking water into the cylinder.

A running V6 is always of some value to some one who's isn't. .... Head gaskets are not a big job. As long as there's no water damage, that may be all you need to do. I'd do a compression check first to get a baseline, and then pull the heads. Look for corrosion and water intrusion, especially on the blown side. Maybe all you'll need is a gasket. If compression is down (below 90#) on the rest of the cylinders besides the bad one, but even, then a rebuild to freshen it up is the way to go, but I'd start seriously thinking "new motor" before that much of a rebuild. Since you're asking about rebuilding, I have to assume that you're not likely to be able to be rebuilding it yourself and will be having to pay "full price", so to speak for the rebuild.

There's a lot of 20 year old motors being run every day.



Darlene

[drcoastline]

Thanks again.

I would be paying full price for a rebuild, I don't have any idea what to do to rebuild a motor. Judging from the sales price of older 150's I think I may be better off just getting a new motor. Thanks again.

[eggsuckindog]

I think your right, the age doesn't justify the cost of a rebuild, plus you could run into bolts breaking off and stuff which would just add time to the job.