Horse Power

Blue_Runner

Blue_Runner

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Ok folks, I got a serious question here. I just bought a vintage 1976 V20 that has had the transom completely redone. The previous owner had the work done, then he bought a set of twin counter-rotating 140hp 1989 model Johnson outboards to hang on the back.

The motors are not yet hooked up, just hanging there.

My question is - is this too much??? I've never seen more than twin 115 outboards on the V20.

Thanks,
BR
 
By the way...it is not a full transom so there is no bracket to provide additional floatation :-[

Also, no trim tabs.

Both motors ar 25", so if I go back to a single setup with one motor, I think I'll need a jack plate won't I? It seems like the jack plate would make it harder to hook up the steering arm due to a 6" setback? Is that the case?

Also, one final question - how fast do you think this baby will run with a single 1989 140hp ob?
 
If it were my boat, I'd get what I could for the twins and put it toward a single 150 or better 175...the 140s being a counter rotating pair, it shouldn't be too hard to find a good home, provided they're in good shape...transom, if previous owner put it back like factory, should take a 20" shaft motor...
 
Welcome, BlueRunner :)
Yes, I think twin 140’s are too much for that boat.
Assuming the hull is structurally sound (?), I don’t think the coast guard rated it for that much horsepower, then or now. Maybe they allow for more hp for twins than a single motor - best check that out. Could be an insurance/liability issue.
Also, the weight of twin 140’s may put your scuppers underwater when the boat is at rest. I don’t know if twin 115s will save you much weight.
I love the idea of twins on a V20, especially if you are running offshore. Are you?
Since you already have the boat, the first thing you need to do is see if the boat will plane off with just one engine running at a time. Twins become a disadvantage if you cannot plane on one. The surviving engine will burn too much fuel on a long run back to port. You would be better off with one big motor and a 9.9 hp kicker to bring you home just in case.
My V21 takes a 25 inch shaft. The cavitation plate on the motor should be about an inch below the running bottom in front of the lower unit. Twins can go a little deeper because the boat will rock side to side in substantial seas. You must keep the water intake submerged, but too deep will cause excess drag.
Good luck and enjoy your V20!
 
Answering the questions first:

1) Yes, this is the one on eBay last week.
2) I would like to run offshore, but I don't know how likely that would be with only 60 gallons of gas. (2x30)

The guy happens to be someone I know (but not well at all). The boat was 1 mile from my house and I found it on eBay - go figure.

I went and took a look at it. The floor is completely solid but in need of cosmetic work. Transom work looked great - no spring whatsoever even with the twins hangin on.

Best I can tell, this boat needs:

1) Sell two 140hp Johnsons and buy a 175hp.
2) Sand and paint the outer hull - although it looks pretty darn good like it is.
3) Something needs to be done to the floor. Like I said, floor is strong but tired looking and has a hairline crack or two - what should I do to make the floor look better?

Nobody said yeah or nay on the jack plate idea - is it a bad idea to use a jackplate to hang a 25" shaft ob on a 20" transom? Or do you even need to?

Thanks for your great input! Ya'll are the real deal. That was fast!!!

Thanks,
BR
 
As much as I would be intrigued at seeing how that boat would handle and what kind of speed could be obtained (probably in the mid 50's), I would agree with the above statements. They're gonna burn a lot of gas too. I would go with a minimum of 150 hp but if you have a need for speed, go with 200 - 225hp. Do it now before you invest a lot of time into the twins.
 
If I could get at least 30mph out of the 140 johnson I'd be happy. Your thoughts on that please?

God its nice to have a whole website full of expert advice dedicated to my own little world ;D
 
I have a 76 cuddy and I have a single 175 on a bracket. I crusie at 30 and I can get near 40 if I trim it right but that is WOT and i perferr to not run like that all the time.

Good Luck
 
There is a thread around here about your boat a couple of the concerns were:

As somebody already said here the scuppers are going to be low, I expect it will be wet all the time.

Where could you put twin controls was another, I have no idea.

I've seen v-20's with a 225 on it, mine has a 200 & will go 46mph (GPS).

I think you are mistaken about the fuel tanks too, other here would know better but I think it's 2-20 gallon saddle tanks.

I hope you got a good deal & I'd love to see how fast it will go but before I put much $$ & time into it I'd do the following:

Check the compression on those outboards.

Check the lower units for tolerances - counter rotating lower units are high $$.

Check the transom, that's a heck of a lot of stress with 280 HP.

Put it in the water, I'm afraid it may be pretty wet.

Sorry to be so negative, maybe it's my mood today. Good luck with your project.

Doug
 
Im pulling 34 MPH with a fairly WOT but she cruises real nice at about 30 with my 89 Yammi 130. 140 should be plenty but I would think about a 150, nice all around engine for the v20.
 
If you want to go offshore . . . twin 140's carb OMC engines and 60 gallons of fuel won't take you very far.

Also anything above 40mph in the v20 seems too fast to me.

just like everyone else said already . . . . Trade/ebay them both and put your money towards a newer more efficent engine 150 + hp and 15hp kicker.
 
I agree with all of your responses. My intent when I purchased the boat was to sell one motor and go back to the single setup with the other.

First I'm going to get the compression checked out on both engines. Next, I'm going to get rid of one of these motors and try the other one out as a single setup. If that proves to be too little hp, I'll sell that motor and buy something in the 150 - 200 range.

That brings me to my next unanswered question that I asked a good ways up in this post:

In order to hang the 25" shaft motor on this 20" transom, will I need a jack plate? I saw one that looked as if they had taken a 25" and mounted it high on the transom rather than using a jack plate - can that be done?

Thanks,
BR
 
25 inches on a 20inch will need a jack plate or an OB bracket. The cavitation plate on the outboard needs to be level with the bottom of the hull.
 
My V-20 had a 155 Evinrude that on its best day pushed the boat to maybe 37-38 mph, with no load and an absolutely clean bottom (and a tail wind ;)). I replaced it with a Yamaha HPDI 200 hp that took me to just under 50 mph in nothing flat. My 155 was a great, miserly engine: I never burned more than 7 gph. But add several people and/or a few months worth of bottom slime and forget it. So it really depends on what you want to do with it, what loads you will carry, and whether the bottom stays clean!
 
Welcome on board! I have a 1990 V20 Sport powered by a !990 Force 150, actual hp rating would be more like 135HP. Carrying four adults,3/4 tank of gas and fishing equipment I'll do 26 Mph @ 4000 Rpm. If I had to replace the Force today and I had the money I'd opt for a 150HP four stroker, for about half the cost and more of a reality for me I'd buy a 150HP two stroker. I also have a 1985 9.8 Merc kicker. It's my safety valve and I troll with it. Good Luck! Bill Mc ;D
 
One thing not covered yet is that if you have a 20" transom, you would want 15" legs on the twins. Those 25" shafts mounted off centerline would run way deep in the water. My guess is that one of those 140's would make for a very adequate fishing boat. I've got a 150 merc on mine and it cruises at 26kts at 4k burning 6.7 gph. Thats right about 3.8 mpg in ideal conditions. If I'm easy on the throttle I can run around 3.2 mpg all the time. The other point I'd comment on is that if the boat looks decent, I'd try a good compound/wax job before I jumped into painting. Look into getting the floor gelcoated, its harder than paint and will last much longer. I bet you could get a splatter finish done real reasonable. Good luck, they are great fishing boats.

Airslot
 
Second thoughts:

Given the overall age of the hull, and the fact that it had a shot transom that needed to be repaired, and that even IF repaired correctly has still sufferred flexing and fatigue of the original glass during the time prior to the repair as the transom was rotting, and the fact that you really don't know if the rot extended into the stringers ...
I would not put more than a single 150 (with a 9.9 kicker) on this hull. I feel that in most cases a 150 is the best single hp motor for a v20, anyway. The 140 is a crummy short lived motor because they are trying to pull 140 hp out of a 4 cylinder block. Those motors with the 25 inch legs were taken off an offshore runner and given their age - one or both are on the way out. I would sell them and buy a 150 and a 9.9 kicker.
 
Hey guys...no scuppers on a '77...

BR, your transom looks just like my '74...I don't think you need a jack plate, just a 20" shafted motor... just hung a 150 Honda w/20" shaft and it's a perfect setup...jackplate's just gonna add cost and weight and probably not much if any performance...I think your twins will sell beter if you keep them together since they're counter rotating...there's a repower on the board w/a 140, but it's a new one(rated at the prop)...I just don't think you're gonna be happy with one of those 140s ::)
 
Thanks for the insight guys...

Reelapeelin, I agree I probably won't be elated with a single 140hp, BUT for 2500 bucks happiness is relative :)

I've never owned a boat that would do more than 30mph, so I think this will satisfy me for a year or two. I want to be able to striper fish out of Oregon Inlet, so if at least one of these motors checks out and I can get a good 9.9 kicker I think it will serve the purpose.

My father-in-law owns a machine shop and can make me a stainless steel "jack plate" for next to nothing. Of course it won't be adjustible, but it doesn't need to be.

Seakindly, yesterday I hooked up some temporary power to each motor and both turned over good. I'm going to haul it down the road and get the compression checked.

Airslot, what is a splatter job? Also, I am a gelcoat idiot, so tell me this - will gelcoat hide a crack in the fiberglass? What about the splatter job (or is that the same thing?)?

I have so many questions.

BR
 
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