Question for Dhadley?

[85Sunbird]

I have a 1977 115 evinrude and I was reading on here last year where you were telling someone that you can mill out a portion in the intake to improve horsepower. Something about letting all 4 cylinders pull through the top and bottom carbs....I'm not sure. Can you explain this procedure in futher detail and how involved is it?<br /><br />Thanks:<br />Jason

 

[Dhadley]

Re: Question for Dhadley?

Welcome!<br /><br />Sorry I didnt answer sooner but I have been traveling for business.<br /><br />We turn the manifold into a plenium. We remove the wall between the throats of each carb. It allows 1 cylinder to draw from two throats. There are some slight carb mods and a special gasket you have to use also.<br /><br />The first thing to do is to make sure you are getting the most out of what you currently have available. Otherwise you may not gain much. <br /><br />Tell us more about your current set up. Rpm's with an average load, speed (accurate), water pressure, prop, X dimension, intended use, etc.<br /><br />Good luck!

 

[85Sunbird]

Re: Question for Dhadley?

Dhadley,<br />You have helped me before on other occasions. I used to be screen name "4link1955". I haven;'t been up here since last year. <br /><br />Here is my set up:<br />It's a 17' Sunbird with a 1973 115 Evinrude. We put a new powerhead on it a few years ago and the new powerhead is a 1977 115 with 135 heads, carbs, and exhaust bubble. I't been bored .030" over and a set of Wiesco Pistons were used. The motor is mounted with about a 5" setback because I'm running the CMC power tilt and trim unit on it. The motor turns about 5400 rpm's WOT with a 19" SS prop. I have the cavitation plate about 1 1/2" above the bottom of the pad. <br /><br />My intended use is just cruising and alittle skiing. I sometimes like to play around with it and get all the performance I can out of it. It'll run about 47 mph according to the gps with the current setup. <br /><br />I'm always looking for more speed out of this thing. I would love to be able to hit 50 MPH with ease. I had read alittle bit about the mod you were talking about and it sounded interesting. What kind of mod are you talkiong about has to be done to the carbs? Can you buy the gaskets you were speaking of?<br /><br />Let me kn ow if there is anymnore info you need about my setup.<br /><br />Thanks again:<br />Jason

 

[Dhadley]

Re: Question for Dhadley?

To be honest, at 5400 there is still some more left in what you have. What brand ss prop is it? If an OMC, is it an SSTI or SSTII? You can tell by the direction of the converging ring. Is the prop still in good shape? Have you tried raising the motor?

 

[85Sunbird]

Re: Question for Dhadley?

Dhadley,<br />The prop I'm running is an OMC. I'm not sure which one of the two it is. How can I tell the difference? You said something about the conv. ring. Yes, the prop is still in pretty good shape. I had it trued and balanced last year. I have raised my motor as far as it will go right now. I even drilled more holes in the motor nounting bracket to get it up another notch. My only opther option as far as raising it would be to put a jackplate on it. Would you recomend me trying a chopper style prop on it to get max performance out of my setup? I know I can't use it for skiing and such.<br /><br />Thanks again:<br />Jason

 

[Dhadley]

Re: Question for Dhadley?

If youre that high and still getting water pressure and good prop bite I see a jackplate in your future. How did the boat respond as you raised the motor?<br /><br />I'm not a fan of chopper style props in this application. If you have the opportunity, try one by all means -- but I wouldnt recommend to go buy one.

 

[85Sunbird]

Re: Question for Dhadley?

The boat responded real well to the motor height change. I went from only turning 4900 rpm's to 5200 at wot. I had a chance to test the boat out his weekend for the first time this year. I able to surface the prop and get 5300 rpms and I reached 48 mph. I just wish I could break that 50 moh barrier. A jackplate is alittle out of my budget right now. I wish I knew a good prop shop that would let me try a few out. I'm sure this old basic omc prop is holding me back a few mph.<br /><br />Anymore suggestions Dhadley?<br /><br />Thanks again:<br />Jason

 

[Dhadley]

Re: Question for Dhadley?

You boat is responding well to your changes. Thats good. You may want to thing about even a manual plate. They're really not that bad. Just watch that water pressure!<br /><br />Yes, I would agree that a good prop shop or performance center is your next choice. Although it will be kinda incomplete until you get the jackplate. <br /><br />You might look for a Raker to try or a Stiletto. They both have more lift than an SST. I dont think youre high enough to turn a Turbo properly.<br /><br />Good luck!

 

[farginicehole]

Re: Question for Dhadley?

Dhadley,<br /><br />Can you please explain what you mean by "water pressure"? Once I finally get my 150XP running properly (on 6 cylinders!), I'd be interested in experimenting with my engine height. Thanks!

 

[85Sunbird]

Re: Question for Dhadley?

farginicehole2,<br />He's talking about the actual water pressure the pump is putting out. They make a pressure gauge you run on outboards. When you raise the motor up out of the water you take a chance in getting the water pickup out of the water also and the motor will not pull enough water to keep it cool. Hope this helps:<br />Jason

 

[farginicehole]

Re: Question for Dhadley?

I see. Thanks for the explanation, Jason!

 

[85Sunbird]

Re: Question for Dhadley?

Dhadley,<br />If I try and go out and find me another prop to try, do you recomend me sticking with a 19" pitch? Thats what I'm running on it now.<br /><br />Jason

 

[Dhadley]

Re: Question for Dhadley?

Rakers come in even numbers so an 18 is what to look for. A 19 Stiletto may bite too hard too. But if it lifts the boat more you may be able to swing it.<br /><br />Anytime you are torn between 2 pitches (sizes), most times its best to go with the smaller one and add bite (technology) rather than take bite out (increase the slip %) of a larger pitch.

 

[85Sunbird]

Re: Question for Dhadley?

How do you add bite to them? Are you talking about letting a prop shop rework it?<br /><br />Jason

 

[farginicehole]

Re: Question for Dhadley?

Dhadley,<br /><br />Sorry to jump back into this thread, but I was wondering if you have any insight regarding my "no spark on 1 or more cylinders, but. . ." thread? That is, assuming I didn't make EVERYONE mad with my opinion about my local dealer (guess I should keep it to myself). Thanks!

 

[Walker]

Re: Question for Dhadley?

Fargin, again I'm not trying to be an A-hole, but one thing we don't do on this forum is highjack someone elses thread.

 

[farginicehole]

Re: Question for Dhadley?

A million apologies. I really seem to be living up to my name so far this week.

 

[Dhadley]

Re: Question for Dhadley?

jason -- yes a prop shop can add "bite". Sometimes we do it with pitch (progressive) or cup or simply extend the cup further around the blade. <br /><br />Its generally more efficient to add than it is to remove.<br /><br />fargin, I'll take a look at your deal now.

 

[85Sunbird]

Re: Question for Dhadley?

Thanks Dhadley!!!!<br />If you get time since you know so much about these motors...take a look at my post on "Idle Exhaust Relief" topic and tell me what you think.<br /><br />Thanks again for all your help!!<br />Jason

 

[Marc J.]

Re: Question for Dhadley?

Hey Sunbird, Is that Greenville, SC? Ever make it to Lake Hartwell?