# HP Question



## czuniga (Feb 7, 2012)

Hello Everyone

Would a 9.9 HP push a 16 ft ouachita its about 66 inches wide at bottom. It does a very nice job on my 1436 Alumnacraft. I think i need to up grade to a bigger engine, but hand tillers in 35 hps are preaty hard to find down here. There are a couple i have ran into in clist but are steering engines. Has anyone ever converted a remote steering outboard into a hand tiller?


Thanks


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## Whoopbass (Feb 7, 2012)

Sure it will push it and get it up on plane unless the outboard is a turd.
It will just take a while to get up to speed and wind will slow it down. Get rid of any unneeded weight in your boat.
I wouldn't even try and convert a motor over to tiller. Be patient and something will come along.


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## JMichael (Feb 7, 2012)

I'd be impressed if it gets a 16x66 up on plane if it's got very much gear and people weight inside. I've never tried or seen it tried with a combo like that so it might. As far as converting to tiller, I'd say it depends on the motor. I just finished converting my motor back to tiller from remote. Some motors only require the tiller handle being installed or removed to convert them while others are going to involve more work and parts.


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## czuniga (Feb 7, 2012)

This is the boat im trying to push, and this is the outboard im trying to push it with. speed is not really my priority. as long as it gets me there. But i do think i need to shop aroung for somehting a little bigger.


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## czuniga (Feb 7, 2012)

this is the engine


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## bbstacker1 (Feb 7, 2012)

I would agree that is a lot of boat for a 9.9. As you said if you are not worried about speed it will get you there eventually. Something to consider, those 9.9's came with a 9x10 pitch prop, if you drop it down to a 9x8 pitch it would keep the engine up in it's powerband a little better (been there done that with a 14 ft utility V-bottom)


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## czuniga (Feb 7, 2012)

BB stacker, 

would changing my propeller give me a little more speed?


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## bbstacker1 (Feb 7, 2012)

I don't know about more speed, it might, maybe a mile or two per hour just because it would be able to keep in it's powerband a little better. My main concern would be to keep the revs up to keep the engine from lugging, lugging is not good, it can lead to excessive carbon buildup.


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## Pappy (Feb 7, 2012)

Guarantee it will plane the boat and do a decent job. As has been stated, you may need to pitch down but would run the boat/engine as it before determining that.
Nice thing about that boat is the large planing surface area and subsequent light surface loading. You may like it. For that engine you can always source a 15hp carburetor and exhaust megaphone. If it has been a saltwater engine you will want to pull the powerhead anyway at some point and replace the water tube grommets as they have a tendency to swell shut after running in salt.


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## czuniga (Feb 7, 2012)

Thanks for the into guys. I will definitely look for another prop. I will get her in the water this Sunday. Is there any way I can actually measure my MPh. Is there any way to intall a tachometer.on these Outboards. Or how would I be able to measure my exact speed. Sorry for all my questions but I'm fairly new. To boating.


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## JMichael (Feb 7, 2012)

Use a GPS to measure your speed.


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## bbstacker1 (Feb 8, 2012)

As Pappy said give it a try before switching out your prop it may work OK for you as is. On the boat I had it was OK with the 9x10 as long as you had no one else and not much stuff with you in the boat, once I had a passenger it just didn't have quite enough umph to get on plane and you could tell by listening to the engine that it was not winding up, the 9x8 fixed that letting it wind out as it should.


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## czuniga (Feb 10, 2012)

thanks i will be giving it a try tomorrow or maybe sunday. However i would really like to at least put wooden floors and there will be several of us fishing off it, So it will be quite loaded. Once i get my hands on a 25 or 35 hp, i will start looking into some modifications for the mean time i think i will definately start looking into another prop. One last question, original paint is not peeling off, overall its preaty good. i just wanna give it an even coat probably tan also. is there any thing i can pick up at home depot or lowes. i was wondering if an oil based paint would do the job.

thanks


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## czuniga (Feb 10, 2012)

Will adding a fin improve my engine performance?


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## River Rider (Feb 10, 2012)

If you are referring to a hydrofoil or whale tail then yes. They can plain you out faster while keeping you from porpoising.


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## Pappy (Feb 10, 2012)

Would leave it off to begin with. You should have no problem planing the longer hull and the same holds true for porpoising. They also create parasitic drag while on plane and with the horsepower you have it would more of a negative for you.


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## czuniga (Feb 12, 2012)

Hello. 

Was in the water today four Guys about 850 lbs. Pushed us really nice. Cavitation plate is about 4 inches beneath bottom of boat. Might raise it if it improves performance.


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## czuniga (Feb 12, 2012)

Hello. 

Was in the water today four Guys about 850 lbs. Pushed us really nice. Cavitation plate is about 4 inches beneath bottom of boat. Might raise it if it improves performance.


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## czuniga (Feb 12, 2012)

I did have problems with 9.9 could only get it to start on reverse or foward. Could not stay I n idle. Any ideas what could it be?


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## Pappy (Feb 13, 2012)

Would adjust the mixture at idle and see if that works to begin with. Yes, you need to raise the engine!


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## czuniga (Feb 13, 2012)

thanks,, 
i was actually really impressed with the performance of this 9.9 really did a good job...


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## czuniga (Feb 13, 2012)

i will look into another prop once i fix this idle problem im having!!!!!


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## czuniga (Feb 16, 2012)

Hello 

Fixing to order a new prop solas amita seems to be what fits my budget at tis time. After removing the one I have right now. Its a Michigan 012111 which happens to be a 9.5 by10 pitch. Solas makes a 9.25 by 8 wondering if I should go any lower or higher since they also make it in 7 pitch?


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## bbstacker1 (Feb 18, 2012)

Did you get the idle issue fixed and the engine raised as Pappy suggested? I would get those things taken care of first before I ordered a new prop, you might find you don't need one. At any case, I would not go lower than an 8 pitch.


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## Johny25 (Feb 21, 2012)

Your motor can be made into a 15hp as someone mentioned above. I did the mod on my 87' 9.9 and it made a world of difference! I did the mod after I added 150lbs or so of custom flooring and seats in my 14ft lowe. We went from not getting on plane to planing without a problem after the conversion. Carburetor and exhaust horn/tube was all that I had to put on it. But if you are not comfortable with working on your motor I would not advise it. The exhaust tube required the removal of the powerhead. But the HP gain was substantial. I also made a jack plate to raise the motor almost 2" which also made a big difference.


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## czuniga (Mar 18, 2012)

So I changed my prop to a solas 8 pitch. My engine revvs up nicely. Seems its fine up in it's power band. But does not quite push the boat like it used go. Seems like it creats an air pocket. The prop is about one inch under the lowest portion of the boat. Will a whale tail help?


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## Pappy (Mar 19, 2012)

Going down in pitch in your case means that the engine will be revving quite a bit to maintain a good cruise speed. You may like the original prop better. If you can explain your issue better about the air pocket I may be able to guide you a little better.


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## czuniga (Mar 19, 2012)

Yes,,

when it gets up on plane ans engince is reving at its full rpms eems to suck air from the surface and seems like the propeller slips,, i and wondering if an whale tale would help. Also could de be fabricated out of plane old aluminum or is it a product that needs to be purchased. 


thanks


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## bbstacker1 (Mar 19, 2012)

Sounds like you raised your engine as suggested? Maybe you went up a little to far.


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## czuniga (Mar 19, 2012)

Hello,

yes i did.. i made a homemade bracket. ill try to post a pic, but it worked fine with my 10 pitch prop. i did not have this problem before. My guess is the 8 pitch prop is spinning faster thus creating some kind of suction from the surface. I am wondering if a hydrofoil would help. since my bracket is bolted and i would really hate to drill more holes in my transom.


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## czuniga (Mar 19, 2012)

i was able to get the pic up,, you can see the bracket


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## Johny25 (Mar 19, 2012)

Have you tried trimming the motor down one more slot and see if that helps? It should put the prop another 1/2 inch into the water. I should have mentioned that when I jacked mine up I test ran it before putting holes in the transom. A 1/2 inch up or down can make a world of difference.

And if you are sure your prop is 1 inch below the bottom of your boat it shouldn't be sucking air. I think you may be under propped which can also make it sound as though it is sucking air. The last little bit of throttle turn will make motor will rev higher but the boat won't go any faster.


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## Johny25 (Mar 19, 2012)

czuniga make sure when doing any changes to motor height and prop changes that you run the boat exactly the same each time so you know what results are happening from what. If you had 4 people in your boat before then put 4 people in again when testing the new prop. Lesson the amount of variables in the equation and you will have a much easier time


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## czuniga (Mar 19, 2012)

If I'm under propped a hydrofoil wouldn't help right?


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## czuniga (Mar 19, 2012)

If I'm under propped a hydrofoil wouldn't help right?


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## czuniga (Mar 19, 2012)

My engine is in its lowest slot. I think my next step would be to try a9 pith prop. Or removing the bracket for a test run. But without bracket sits well underneath water.


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## Johny25 (Mar 19, 2012)

I am not a fan of hydrofoils myself. And no, if it is over reving because your under propped then a hydrofoil won't help. Put your 10 pitch back on and see what happens. Make sure the weight of the boat is the same. Play with all the trim settings and see what happens.Yes even the other way. Take tools to remove jack plate also and remove it if you cannot get it to stop slipping or whatever. Then test props again.

I have a hard time believing that your 9.9 is spinning so fast that it is sucking air. This is a photo of where I had my 30 hp motor, about 1 inch under the water and it wouldn't do what you are saying. And that is 3 times the HP. The only way I could get prop blowout is if I had it trimmed to the very back slot. And when you get blowout it is very noticeable. Prop spins, motor revs really high and boat goes nowhere or stops accelerating.


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## bbstacker1 (Mar 20, 2012)

czuniga, Looking at Johny25's picture is your setup about even with his, ie is your lowest plate pretty much even with the bottom of your boat or slightly lower? I can't really tell from your photo but it looks like you have a short shaft engine and I am guessing you raised the motor about 2 inches maybe a little more? If you are even or a little above the back of the boat with your engine you might have to lower it a little bit. My next thought would be to the prop itself, have you tried running the boat with the 10 pitch and the 8 pitch under like conditions, if so and this only happens with the 8 pitch then I would wonder about the prop. I am not familiar with Solas props (maybe one of the other folks on here can inform me/us) but my question would be does this prop have a rubber "slip" bushing between the hub and outer prop body, if it does could this be slipping? I know it is a new prop but that doesn't mean it can't be defective. If you suspect the prop is slipping find a way to mark the inner and outer sections then take it out and try it, after it seems to slip then check the marks to see if they have moved if they have the prop is bad.


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## czuniga (Mar 20, 2012)

I ran about the same amount of weight the first time with the 10 prop. I did really good speed wise it was just that the engine seem to be having a difficult time sounded like i was straining the engine too much. When i placed the 8 prop it reved up really nice however i ran into this problem. It was about the same amount of weight. Three of us and some added weight of mods I will try to take a picture of my set up so i can post as soon as possible. It sounds exactly like Johnsons said the last bit of throttle is where is sounds as slipping or sucking air and it doesn't go any faster. Im guessing that i might be under propped. maybe i went too low with an 8. The thing is i can put my 10 back in there but i would be over stressing my engine. I need to try to borrow a 9 and give it a try see how it performs. I am just trying to get the best setup possible until a good deal for a 25 of 30 hp outboard comes along.


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## Pappy (Mar 20, 2012)

The 8" prop has very little rake (angle that the blade is attached to the hub, not the pitch angle) compared to the 10" propeller. If you are high enough on the transom then the prop may very well be aerating at higher RPMs. Rake, among other attributes, helps to hold water on the blade better as the rake angle increases. 
Best way to measure your current engine height is to make the cavitation plate parallel to the bottom and measure with a straight edge to the bottom and tell us where it is. The bottom of aluminum hulls have all kinds of junk on them to obstruct and feed air into a propeller. As I said earlier, you may be better off using your stock prop.


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## czuniga (Mar 20, 2012)

I will double check my height, just to be extra sure, if its off an inch or so, it would make a difference right? What would be the inconvinience if it sits a couple of inches under bottom of boat. 

thanks


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## czuniga (Mar 20, 2012)

im planning on removing taking exact measurments and removing the bracket and taking it out for a test run. WIll let you guys know how it goes,,


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## Johny25 (Mar 20, 2012)

It will cause a little more drag if it is down lower is all, not really that big of a deal. But I would make sure that it was too high and not just the prop before removing and putting more holes in the transom


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## czuniga (Mar 20, 2012)

Some pics


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## czuniga (Mar 20, 2012)

Pic


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## czuniga (Mar 20, 2012)

This is the setup. If I remove the bracket it will sit 2.75 inches below 
BOAT. That is my next option.

Wouldw this be too low


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## Johny25 (Mar 20, 2012)

I can't believe you are cavitating where the motor is currently. That pic looks plenty low not to be cavitating. I still think it is a trim or prop issue IMO. And no it won't be to low if you go down to where you are talking but it will give a little more drag is all. So have you tried trimming the motor up a notch to see if you get blowout?


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## czuniga (Mar 20, 2012)

Yes I have tried raising it up a notch and sounds worst. The bracket only raises the outboard 2.75 inches. But from I have read online and on other threads. My setup should be just about right. My 10 prop stresses my engine. Perhaps I went too low in pitch with an 8


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## Johny25 (Mar 20, 2012)

Ok well it won't really stress your engine running the 10 pitch but it may not get to recommended RPM to produce peak HP. I am guessing you should be 5500 to 6000 RPM with your 9.9 Do you have a tach? This would answer a lot of your questions about what is really going on


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## BrazosDon (Mar 21, 2012)

Where are you located? I have an 18hp on a 14X48 jon boat and no problems. The boat is rated for a 30hp I believe. I think maybe an 18 or 25 would work well for you. Good luck from Texas.


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## czuniga (Mar 21, 2012)

Hello i am in brownsville the deepest part of texas. Once i remove the bracket its only 3 bolts i run it see how it does, ,should only be 2.75 inches under bottom of boat. And yes hopefully, a good deal will come along another outboard. ill just have to wait for that to come around


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## czuniga (Mar 26, 2012)

hello, 
i think i am definately underpropped. i removed the bracket engine sat about 2.75 inches below boat. Had the same weight on boat and still sounded like it slipped at full throttle. Glad i did not buy hydrofoil before running this test. I think i might need a 9 pitch prop. I had and 10 before and i dropped to 8 . Does anyone have a 9 that is willing to sell?

thanks


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## bbstacker1 (Mar 26, 2012)

I still think I would check the prop to make sure it hasn't spun in the hub.


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## Johny25 (Mar 26, 2012)

It sounds like it is definitely the prop, either spun or under propped. Why haven't you put that 10 pitch back on yet and run it? This will clarify the issue whether it is a spun prop if it does it with the 10 pitch also now.


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## czuniga (Mar 26, 2012)

With the 10 prop the engine sounds like its gonna pop. Sounds like ovrtstressing. Like a standard truck when its asking for the second gear


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## czuniga (Apr 13, 2012)

hello,

just wanted to update this thead hopefully it will help someone like new like me. I was definately underpropped. I removed the bracket and engine sat 2.75 inches below and still ran the same. I ordered a new prop (actually it was an even exchange with iboats) and i reinstalled my bracket and ran the engine as i had it before. Only now with a 9 pitch prop and ir ran really nice. Planed in no time and did not slip at all. Big difference from when i ran it with a 8 pitch prop. I think nine was definately a good choice. I have another thread of how to convert this 9.9 into a 15. These guys have been extremely helpfull. Dont know it would run into prop issues once i add a few more horses to it. But as for now its great. Thanks to everyone..

great site


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## Johny25 (Apr 13, 2012)

Just to warn you in advance, after doing the HP upgrade you will most likely be under propped again. You are going to be adding 33% more horsepower to the motor. You should invest in a tachometer for your engine so you can give us info and we can make sure you get the correct prop on there. My guess is you will need a 9.5X10 pitch and maybe even an 11 pitch? This is all good though, the higher pitch you can turn at your motor's recommended RPM the faster your boat will go : )

Thanks for the update also : ) I like when people come back and finish threads


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