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Author Topic:   Outrage porpoises
Scott Blunk posted 09-22-2000 09:36 PM ET (US)   Profile for Scott Blunk   Send Email to Scott Blunk  
What would make a 1979 V20 Outrage porpoise?

Hull is in excellent condition, bottom is like new. Powered by a 175 HP Johnson.

I know the answer is out there.


Ed Stone posted 09-23-2000 08:28 AM ET (US)     Profile for Ed Stone  Send Email to Ed Stone     
Hey Scott,
I would think if you adjusted the trim on
your motor you should fine the sweet spot
that stops porpise and rides nice.
If I have my motor trimed to high it will
start to porpise.
Good luck.
Barry posted 09-23-2000 12:06 PM ET (US)     Profile for Barry  Send Email to Barry     
My experience is similar. Depending on the boat/motor, having the engine trimmed out too much could cause it. Weight distribution of people and gear seems to be a factor, specifically too much weight toward the bow. Also, height of the engine.

How low is the 175 mounted? Any kind of fin (DoelFin, Sting Ray, CoBra, etc.) on it?

kingfish posted 09-23-2000 09:32 PM ET (US)     Profile for kingfish  Send Email to kingfish     

I'm betting on trim, especially if the 175 is near or above the rated maximum horsepower for the Outrage (?). Bear in mind also, that if the motor is a newer model (in which the power is rated at the prop rather than at the power head, where horsepower was rated in '79), you may have more hp compared to the boat's max. rating than you think.

If trimming the motor down doesn't do it, consider trim tabs. They *will* do it.

jimh posted 09-24-2000 01:04 PM ET (US)     Profile for jimh  Send Email to jimh     
Porpoising--the bouncing of the bow--is generally due to having the bow trimmed too high.

If your engine has power trim, experiment with lowering the engine trim slightly, which should bring the bow down. No power trim? Bring the engine down one notch.


Tom Byrum posted 09-29-2000 01:06 AM ET (US)     Profile for Tom Byrum  Send Email to Tom Byrum     
Last weekend while heading out tuna fishing in my 18'outrage I was running alongside a 20' outrage that was porpoising continually for over twenty miles. Sometimes it would start to porpoise pretty bad. Didnt look right to me at all.
witness posted 10-04-2000 07:34 PM ET (US)     Profile for witness  Send Email to witness     
My 1978 v-20 does the same when trimmed at all (also with a 175). I've only had the boat for this summer, but I've added a 2nd battery and some other weight in the back. Originally this boat(Big-z says) had trim tabs. It seems that they would definately help. I'm not sure what I'm going to do. Ideas include adding trim tabs and adding an amstrong bracket. I'm also thinking about repowering with twins and am afraid the action will get worse. I may also sell this boat and get a 25 outrage. Even though I love the boat, 5 more feet is enticing in the area I normally play in :)
bigz posted 10-05-2000 06:36 AM ET (US)     Profile for bigz    

Finally welcome to the forum --- I thought you'd have joined in the bitter batter long before now --- know you have been an active reader ---

Glad she is still a float -- chuckle -- yes the previous owner mentioned the trim tabs and there were parts still attached before we had the transom cleaned up --- these were the fixed spring loaded type made of heavy aluminum with stainless hinge pin and a spring that must rate at 50lbs or better --- I have a brand new pair if you want them --- though I would recommend Lenco Electro magnetic which you can get at Shoreway Marine up in Berlin NJ --- personally would give that a try before anything else ---
I have subsequently found out that the original "new" deep V 20 Outrages were prone to behave strangely but no definite reasons can be given for this handling characteristic and consequently in later models the hull design was modified.

If your thinking of an Armstrong bracket, instead of it I might suggest a hydraulic jack plate with a 10" set back, since you do boat in some shallow water if I recall. Not only will it be less $$$ but will offer overall better performance. If we still had the 20, I would have install one and the controlled trim tabs but as you know the 27 came along ---- end of that story ---

Sure some others will have some helpful advice on a possible solution to this situation ---



witness posted 10-05-2000 10:54 AM ET (US)     Profile for witness  Send Email to witness     
Thanks for the quick reply (as always!). Is it possible to put a pair of twins on and still put both jack plates and/or trim tabs on? I thought about jack plates, then forgot (great idea). It seems kinda tight with both, but I would be curious what you thought, or if anyone out there has twins on a 20' outrage with trim tabs I would be very interested.
witness posted 10-05-2000 10:55 AM ET (US)     Profile for witness  Send Email to witness     
...maybe I should start a new thread... ...I'll wait and see.
bigz posted 10-05-2000 12:20 PM ET (US)     Profile for bigz    
Mike well there would be a lot hanging off the rear end of that 20 for sure ---should be room for two of the plates I mentioned, aren't much if any wider than the motors mounting bracket ---

Knowing her I would probably opt for a used '97 or newer 175 hp, if you could afford it a new 135 or 150 Optimax or the 150hp HPFI Yamaha and then add a 9.9 hp kicker --- set up a dual binnacle control so you can control the kicker from the console and add easy steer to do the same for steering the kicker whether the big guy is in the water or not ---

I just don't see an advantage to just an offset bracket like the Armstrong unless it is coupled with a hydraulic jack plate --- one can argue it puts you out in "cleaner" water well heck so does a 10" offset jack plate plus it is cheaper offering a lot more trim options ---

Of course I think the trim tabs are still the first step to try.

You have to send JimH a photo of her, I know you did a lot of work this spring, loved to see her or send one over to me ---


lhg posted 10-05-2000 02:40 PM ET (US)     Profile for lhg    
Although I have absolutely no experience in or with the 20 Outrage, 1978-1984, the first of the 2nd generation Outrages, I remember reading other "porpoising" complaints on previous Whaler Forums on this hull. The boat has the "shallowest" Vee of any of the Outrages in this series, but I don't think that's the problem. All of the complaints seem to involve the OMC engines of the same years. I believe the problem is the inadequate trim range of those engines. For years, Mercury, the inventor of Power Trim, advertized that their trim system was superior to OMC's, in that it had much more range of trim, including much greater "tuck in", and "trim out & up". Indeed, I have seen many older OMC V-6's on boats that won't even tilt the lower unit clear of the water, whereas the Mercs always did. I believe your problem is that the OMC engine can't trim in enough on this particular hull to eliminate the portpoising under certain conditions.
You may need a newer engine, or at least consider the aluminium "wedges" (by Springfield Marine or CMC) that can be bolted between engine and hull to correct this problem. The newer OMC's now have increased trim range.
bigz posted 10-05-2000 03:04 PM ET (US)     Profile for bigz    
Larry you have a good point and might have hit on the problem. The motor however does move in both directions up and out and down and in but the transom angle might not allow it to get down and in enough to have the desired position --- wedges might solve the problem -- I'll send you a photo the motor was not all the way down in it but will show the transom in relation. I do recall that when I put it at max tuck in the hood was at a slight angle aft and frankly it took a while to plane out but really didn't experience any other drastic misbehavior.
bigz posted 10-05-2000 03:14 PM ET (US)     Profile for bigz    
Mike for your information, received from Chuck Bennett at Whaler, your V-20 was one of the very first made --- January 11,1977 and shipped as a '78 model to Johnson & Kirby out of Miami, FL. How she ever found her way back up to New England in the early 80's is a good guess ---

The specs show that with a single 175hp was able to achieve 49 mph and with dual 85 hp -- 42 mph.

I'll mail you the '79 spec sheet --- Tom

bigz posted 10-05-2000 05:01 PM ET (US)     Profile for bigz    
Oops Mike make that December 11, 1977 --- boy arew my eyes getting old --- Tom
Scott Blunk posted 10-05-2000 10:27 PM ET (US)     Profile for Scott Blunk  Send Email to Scott Blunk     
Finally I think we're getting somewhere. I have been trying lots of different things to try and figure this deal out. And I am thinking the trim angle when all the way down is not close enough to the transom. In fact the motor is not touching the angle adjusting rod. A call to my local OMC friend prompted the question, "is that a 17 degree transom?" I'll check that in the AM.

Thanks for all the great help...what a forum.


Tom Byrum posted 10-06-2000 02:12 AM ET (US)     Profile for Tom Byrum  Send Email to Tom Byrum     
Scott the 20' outrage I was referring to earlier did have a OMC on it as Larry stated. It was a Johnson 115 that appeared to be a couple years old. I think it was an Ocean Pro. He wanted to cruise at 25 or so and I wanted to cruise at 35 or so(one of the few days a year you can do that in the North Pacific Ocean)and every time he tried to speed up he would start to porpoise. All the time my 18' was perfectly stable. There was something definitly wrong.
bigz posted 10-07-2000 08:05 AM ET (US)     Profile for bigz    
Scott was year is your Johnson? Tom
Scott Blunk posted 10-07-2000 10:28 AM ET (US)     Profile for Scott Blunk  Send Email to Scott Blunk     

The engine is a 1983, very low hours and in excellent tune.

Could the fuel level have an effect?


tbirdsey posted 10-07-2000 10:46 AM ET (US)     Profile for tbirdsey  Send Email to tbirdsey     
Here's my two cents. My Outrage 18 with 150 Merc will start to porpoise almost immediately if I trim out too far and the water is the least bit choppy; bring it back in just a hair and it stops immediately. In other words, the 18 at least, is very sensitive to trim, water conditions, etc. As Ed said earlier in this thread, you gotta find the sweet spot. I'd be looking at the trim angle very closely to make sure you can trim in far enough and would be surprised if you have to get more drastic than that.
bigz posted 10-07-2000 11:13 AM ET (US)     Profile for bigz    
Scott --- well that 65 gallon tank runs from just forward of the motor well to the console, that really shouldn't have an effect!

Witness is running an '82 175 Johnson on the 20- '77/78 Deep V --- so you both have the same basic set up --- I think Larry hit the nail on the head --- suggest both try some alum angle so you can achieve more tuck --- least expensive starting point

Another company who Clark Roberts thinks might have a good hydraulic jack plate which can vary its set back (plus they also make wedges) TH Marine might check them out --- Tom

Alioop posted 10-07-2000 07:48 PM ET (US)     Profile for Alioop  Send Email to Alioop     
Engine installed height has a great effect on poporsing. If the engine is too low the cavitation plate can cause the boat porpoise.
Cal posted 10-08-2000 03:05 PM ET (US)     Profile for Cal  Send Email to Cal     
Tom - Any chance of getting a copy of the '79
Outrage spec sheet you mentioned earlier?

My Outrage has a square hinged plate on both sides of the stern. Each plate has a center bolt to push the lower plate further down into the wake. Is this an earlier attempt to correct porposing?


bigz posted 10-09-2000 08:02 AM ET (US)     Profile for bigz    
Cal I'll send over, it is in jpeg format.

Those were the early attempt at trim tabs and I heard they worked to some slight degree. A lot were replaced with Olson tabs which used a spring loaded hinge when the originals rotted out -- problem was the Olson's were always in the down position until the thee boat got up on plane --- (the ones on "witness" 77/78 20 were gone early on and the Olsons tabs were also shot when we got the boat -- previous owner who had her from '81 relayed this information). Tom

OutrageMan posted 10-13-2000 10:44 PM ET (US)     Profile for OutrageMan  Send Email to OutrageMan     
I own a 91 22 Outrage with Whaler Drive and a Yamaha 250 Vx on it. I had a similar problem with porposing - and port torque list. I thought I would find a solution for less than new twins or a jack plate.

I found it in a 35$ Dole fin. It is a wing like device that used four bolts to atach to the cavitation plate. This is the best investment I have ever made! It allowed me to use the complete range of trim, removes the torque list, and best of all allowed me to trim out the porpousing.

It basically works on the principle of assing additional lift to the transom.

This bost also planes much quicker and really digs in during turns.

I highly recomend this mod.


bigz posted 10-14-2000 10:59 AM ET (US)     Profile for bigz    

outrage man--

I am glad the doel fin helped you out --- the problem with the Whalers in this discussion is they are the original deep V hull Outrages your '91 has a different hull -- it appears however the problem is more the outboard used, in both cases they are OMC early '80 models where the trim tuck in angle isn't sufficient to counter/correct this problem --- thus the suggested use of transom wedges --- I believe Witness has already tried a Doel with just limited success ---


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