120hp 'Rude needs prop for Bayliner

[um0RION]

Hey all, im looking for a prop for my 1991 Evinrude that had its prop shaft broken off. I found this template somewhere and thought it'd be the most helpful. BTW the boat weighs ~1490lbs with a 90hp Force on there, I dont know what it weights with my 120hp Evinrude.

1. Year, make and model of boat 1990 Bayliner Capri 1800 BR
2. Length, width and base weight of boat, look for boat decal on back of boat 17' 10" L, 7'0" W
2a.What is the maximum recommended HP for your boat 140, I THINK
3. Number of people and gallons of gas normally on boat 3 people, 15 gallons
4. What do you use the boat for wakeboarding/tube/skiing
5. Is it a Deep Vee and if so how many degrees of deadrise Dont think so
6. Year, make. manufacturer and model of motor 1991 Evinrude E120TLEIE 120hp
7. HP and gear ratio of motor IMPORTANT 120hp, 13:26
If you don?t know the ratio, you need to pull the plugs out and put a piece of tape across the prop and the lower unit and then cut it between the prop and the housing then do the same thing on the flywheel and turn the motor until the tape lines up with each other on the prop, it is easier if two people do this, so one can watch the prop while the other counts the revolutions of the motor
8. Manufacturer?s recommended Wide Open Throttle (WOT) range 5000-6000 RPM
9. Anti-ventilation Plate height above keel of boat if it is an outboard in inches, use a board under the keel and stiking out to the anti ventilation plate for a referene ?
10. Is it a bass boat or does it have a pad bottom No
11. Does it have a hydrafoil, dolefin or trim tabs Yes
12. Make, model, diameter, pitch, number of blades and whether SS or aluminum prop No prop currently
13. WOT RPM and speed from your current prop and how much gas and how many people were in the boat for the test data and is the speed by GPS. Make sure you trim the prop up until it starts ventilating and then just trim in until it quits ventilating. If you do not have a tach you can buy a digital tachometer and hour meter here: http://cgi.ebay.com/ebaymotors/Tacho...Q5fAccessories $ 35 Bought engine without prop
RPM _________ Speed ______ GPS ______ No. of people ______ Gal. Gas ________
14. Are you at sea level or a higher elevation, give us the elevation in feet 300ft
15. Has your motor been tuned up lately and have you checked that the carburetor butterfly is opening all the way by just pushing the throttle at the helm and not at the carburetor, checked compression, and looked at the plugs and checked spark as well as timing and advance, all of the foregoing could be the reason your prop is not attaining full RPM NO
16. How long has this prop been on the boat and why, at this time, do you think it is the wrong prop
17. Does the prop show any damage that you can see
18. What problems are you trying to cure or what are you looking for the boat to do that it is not doing the way you think it should or to your expectations The boat needs to be a recreation boat right now, for skiing, wakeboarding, and pulling a tube. Later it needs a prop for fishing, or cruising the lake/being fuel efficient.
19. If you are trying to attain a better cruising speed and fuel savings or trying to attain a faster speed I will want you to take your boat and run it with 1 or 2 people and give me the RPM and speed readings starting at 3,000 RPM in 500 RPM increments all the way to WOT.

 

[um0RION]

Re: 120hp 'Rude needs prop for Bayliner

Bump?

 

[hwsiii]

Re: 120hp 'Rude needs prop for Bayliner

Orion, I show that motor to have a WOT rating of 4,500 to 5,500 RPM, would you please verify this for me.
And thank you for filling out my form, as soon as you verify the WOT RPM I will make a prop reommendation for you, and I show the base boat weight to be 1,500 pounds without the motor.


H

 

[propper_advice]

Re: 120hp 'Rude needs prop for Bayliner

In 1991 Evinrude offered both the long shaft (20") and the extra long shaft (25"). Different props. Just FYI

 

[um0RION]

Re: 120hp 'Rude needs prop for Bayliner

Orion, I show that motor to have a WOT rating of 4,500 to 5,500 RPM, would you please verify this for me.
And thank you for filling out my form, as soon as you verify the WOT RPM I will make a prop reommendation for you, and I show the base boat weight to be 1,500 pounds without the motor.

H

I have the engine specs from the service manual I purchased, which specifies "full throttle operating range" as 5000-6000 RPM. The engine is rated 120hp at 5500rpm. The book lists a bunch of models, but the last "E" on the model number isnt shown in the book, so I dont know if that model is slightly different.

As for the weight, I have a spec sheet given to me by bayliner, or whoever ships documents for them now, that says the boat is 1490lbs "with standard engine" which is a 90hp Force. I have the 120 Evinrude on it, so its a bit heavier than that.

I dont have any way of checking either of those though, besides looking at what I have in front of me. I havent run the boat, or weighed it exactly, but thats what I have here for materials on it.

In 1991 Evinrude offered both the long shaft (20") and the extra long shaft (25"). Different props. Just FYI

This is the 20" shaft version.

 

[hwsiii]

Re: 120hp 'Rude needs prop for Bayliner

Then I would buy an aluminum 15" pitch Solas Amita 4 blade prop for pulling your skis and wakeboards around and you will be very happy, just be careful when you are running very lite as it may go a bit over 6,000 RPM.


H

 

[um0RION]

Re: 120hp 'Rude needs prop for Bayliner

Ok so 15 pitch for pulling skis and wakeboarders... What would be best for putting around the lake just idling.. same prop, or should I go with a different pitch? Im thinking for either fishing or just a lazy ride around, showing off the lake, that sort of thing.

 

[hwsiii]

Re: 120hp 'Rude needs prop for Bayliner

Orion, I believe you will be very happy with the Amita 15 prop for all of your needs with that combination.


H

 

[um0RION]

Re: 120hp 'Rude needs prop for Bayliner

Sorry to be such a PITA, first boat ever, and I dont have much experience to draw on. Lots and lots of questions! So here are a couple more..

I measured the distance from the prop shaft to the plate, and its 7", or maybe a whisker more. So about that prop, I could only find 13" Diameter models. Would a larger diameter be better? More surface area and whatnot? I read somewhere that diameter doesnt matter that much, but Im not certain.

Also, the manual says they mesaured the 120hp at 5500 RPM. JUST IN CASE the WOT is 5500 and not 6000, would it be better to go with a 17 Pitch? If I went to a 17, Id go faster, but the hole shot would be poorer, right?

Thanks everyone for being patient, your help is great

 

[hwsiii]

Re: 120hp 'Rude needs prop for Bayliner

Orion, that is why we are changing to the Solas Amita 4 blade, for more blade surfae area, it has plenty of that at that diameter.

It is standard in the industry to have the motor develop maximum horsepower at lower RPM than maximum RPM.

You might try reading this for a better understanding of changing props for better performance.

http://forums.iboats.com/showthread.php?t=365653


H

 

[um0RION]

Re: 120hp 'Rude needs prop for Bayliner

Another little update, and a question. Im definitely going to go with the prop hwsiii suggested, the solas amita 4 blade 15 pitch.

Now, Im considering just buying 2 of those props so I have a backup just in case, but I think Id like something different, like something to get the top speed possible. Id use the 15 pitch for almost everything, but as a backup, and for bragging rights, what would get me the most speed? Id stick with aluminum for price sake, but would a 3 blade/different pitch be better for better top speed? Advice/suggestions welcome

Oh also, I needed a new lower unit, so I took off the hydrafoil. Is this going to change anything?

 

[Dhadley]

Re: 120hp 'Rude needs prop for Bayliner

As for the rpm don't worry about going over 6000. Even if you could the rev limiter is at either 6200 or 6700, depending on which ignition version your motor has. Those motors like rpm, no problem. For your "cruising" prop try to set up for at least 5800 with an average load. If your "ski" prop takes you higher the motor will not automaticaly self-distruct.

As for the diameter, your typical prop will be in the 13 1/4 - 13 1/2" range. Generally speaking (not specificaly speaking), props in the 14" diameter range are for barges, pontoons, etc. Don't get caught up in diameter for general use props. Design factors like rake, cup placement, amount of cup etc play a greater role in dialing in a prop for specific use.

 

[steelespike]

Re: 120hp 'Rude needs prop for Bayliner

Without the foil it will be a little slower to plane though the 4 blade should help that some. The bow may run higher.
But your top end may be better.If you feel you need something to improve hole shot
and or bow rise check out something like smart tabs.They will improve hole shot,stay on plane at less power steady the ride and resist no wake speed wander.

 

[um0RION]

Re: 120hp 'Rude needs prop for Bayliner

Im not too worried about the planing, as I will either add the hydrofoil back on, or leave it depending on how the boat runs. I might be more concerned once I get the boat running and on the water, but for now Id like to just get a couple starter props.

Ive read that going from 4 blade to 3 blade changes RPM for a lot of reasons, but as of right now Im still trying to find approximately how much. Like I said earlier, Ill go with a 4 blade for watersports, and for the backup prop Id like something that will go fast. The blade change from 4 to 3 will give me higher rpm's, so Id want a higher pitch right? And each pitch grade is ~200 rpm? (going by memory here, may not be correct) So would a 17 or 19 be better for speed (worse on holeshot)?

 

[hwsiii]

Re: 120hp 'Rude needs prop for Bayliner

Orion, in my opinion we would be better off waiting to see the results with your new Amita. Then we can use that as a baseline for picking a newer higher speed prop for your boat.


H