125 HP on my 1975 20' SF..Under powered ?

[Texascoastalfish]

Hey Yall,
I'm new to this board and purchased a 1975 20' CC. It has a 76' 200 HP Johnson. It has seen quite a bit of Salt water and Im just not sure of its lasting power. It runs and shifts OK. Havent been on water. I want to power down a bit to a 150, or maybe 140 looper. Family member has a 125 Force that has been well maintained. I know the pitfalls of Force outboards, being as they are no longer made,I can get this motor dirt cheap and run it on my CC until I get a newer 150. QUESTION. Does anyone know if its enough to push my craft at 30+ knots ? Anyone know the Min HP rating ? The Max is 175 I believe and this 200 is a big 'ol V6. I am very excited about the clean up and rebirth of my new baby. I live dowm in Galveston Texas and hopefully the pride of West Bay someday. Thanks in Advance !

David E.
1976 20' SF 200 HP Johnson

[mnwnvc]

I am pushing my 20 40 mph with a 115 nice on gas.

[shawn1127]

i ran a 90 honda for 4 years and it was on there 6 years before i got it with the right prop and hight the 125 is fine dose the 200 on there run ok if so why change it
untill it starts giving you problems

[Texascoastalfish]

Well I just bought the boat and it had the 200 on it. I have it in the shop getting tuned and gone through. I haven't run it yet on the water. I guess its just a fuel consumption issue mostly, I hear the old Johnsons are pretty thirsty, and I would like to have newer maintained motor on it. In Fact After it comes back from my mechanic I'm probably going to try and trade it for something in the 140-150 range. My soon to be Brother in law has the Force on an old Bayliner, but in reading about the Force outboards I hear horsepower ratings were not taken from the prop thus meaning a 125 may be a 100 as compared to other outboards. I just dont want to have to be running WOT at cruising speed.

[oldbluesplayer]

first, none of the 70's motors were rated at the prop, that didn't come into being 'till the 80's.

I run an 83 Johnson V-4 115, plenty of get up and go, nice 25 mph cruise, 30+ top end. and light. motor weight on a 20 makes a difference, the V-6 200 will be squatting in the stern at rest, but you sure won't have to work the motor hard to go fast.

the 125 Force ought to be fine, too.

Bill

[Texascoastalfish]

Thanks to all for responses. I want to get out on West Bay and near offshore Rigs ASAP. So I'll be using the 200 ( if it passes inspection ) Thanks for the clarification of HP rating. I still want to re power down to 150 or below.
Anyone want to trade ?

[Bushwacker]

Amen to Bill's advice! I ran the same rig for over 30 years with a 115 V-4, including 6 trips to the Bahamas. I believe the boat will generally ride better with the lighter motor. I couldn't cruise as fast as the V-6's in flat water, but it's always choppy on the Bahama Bank, and I had no trouble staying with them when it got choppy. What you have to remember is that the 20' hull is relatively narrow compared to newer boats, which is one reason it rides so well! When it was designed back in the mid-60's, the biggest motors available only weighed about 300 lbs.
As motor weight goes above that the boat becomes progressively less well balanced IMHO, especially the sf/cc which is more stern heavy than the Seafari to begin with. With my old 1975 115 I could plane at 12-14 mph which is nice capability to have when it gets rough; I suspect min planing speed is a fair amount higher with a heavier V-6. Avg mpg on the Bahamas trips was 2.8 mpg with very heavy load. It's about 4.5-5 mpg with the new motor but you can't justify cost of a new motor based on fuel usage alone, even at $4/gal! Only downside of the smaller motor is that you may not be able to outrun thunderstorms, so you need to watch the weather a little closer, but good it's good seamanship to always do that anyway!

[Fr. Frank]

in reading about the Force outboards I hear horsepower ratings were not taken from the prop thus meaning a 125 may be a 100 as compared to other outboards

This is not true. By the time AMF-Brunswick changed the Chrysler name to Force in 1984, horsepower was rated at the prop-shaft by all outboard manufacturers. Even the 1982/83 Chrysler motors were horsepower rated at the prop.

Your 125/120 hp Force is a good motor, and will push a 20' just fine. It will require a bit more time in maintenance than a new motor, though, especially in corrosion prevention.

I happen to really like those old Chrysler motors. As long as you took care of them, and really important, DIDN'T MESS WITH THE CARBURETORS, they were almost bulletproof.

The Tillotson carbs were really simple, and easy to mess up, as well as easy to repair.

I used twin Chrysler 105 hp motors on my 25 Mako CC commercial fishing boat back in 1976 in the Keys. They never failed to start, never required more than ordinary maintenance, and ran 10-12 hours a day, every day, flawlessly.