why wont it go FASTER!!!

[all duck'd up]

hello everyone

i own a 04 johnson 15 tiller handle on a 14.5 ft duracraft. my friend owns a 1978 evinrude on a 14 ft duracraft. he runs about 24 mph and mine runs 19

how is it that he is pulling away from me and what can i do to make it faster? 6 inches of alum cant make me run that much slower than him


i was thinking new plugs and maybe stepping up to 93 octane instead of old 87; but what else can i do? i cant have this old thing riding infront of me all the time...


just dont think its running at its full potential

 

[raczekp1]

Re: why wont it go FASTER!!!

different prop.
some of them are workhorse and some are fast prop

 

[all duck'd up]

Re: why wont it go FASTER!!!

as far as i know the propeller is factory. how would i know if its a fast prop or workhorse?

 

[raczekp1]

Re: why wont it go FASTER!!!

down at right cornerar props size used in 9.9/15hp
i run 9 1/4 x 11" its fast prop

 

[all duck'd up]

Re: why wont it go FASTER!!!

reading up on it now and what ive got: a higher pitch prop makes you go faster but slower in the hole shot correct? then i guess a lower pitch one is what you called a workhorse

 

[raczekp1]

Re: why wont it go FASTER!!!

in 15 hp/78' i have seen 8x10", its propably strong workhorse

 

[all duck'd up]

Re: why wont it go FASTER!!!

i own the 2004 tho

 

[all duck'd up]

Re: why wont it go FASTER!!!

my modle came with a 9.5 X 10 or a 9 X 11 which would be the faster of the two?

and with this; is the 1st number the pitch or the diameter?

 

[impatico]

Re: why wont it go FASTER!!!

hello everyone

i was thinking new plugs and maybe stepping up to 93 octane instead of old 87; but what else can i do? i cant have this old thing riding infront of me all the time...

stepping up in octane will end up being worse if your engine isn't designed for high octane, the octane rating represents how resistant the fuel is to self igniting under compression. The higher the octane the more garbage like ethanol (not to say it will be ethanol) they put in the fuel. the only good thing about higher octane fuels is that most of them come with more cleaning additives in them

 

[Frank Acampora]

Re: why wont it go FASTER!!!

You are holding on to your Johnson too tight! And ask any woman: Six inches makes a difference! LOL

Seriously, these tin boats and these small horsepower engines are sensitive to loads. How heavy are you compared to your friend? How much load are you carrying compared to him? How is your engine set on the transom compared to his? Is the anti-ventilation plate even with the bottom or slightly above it?

AND, six inches CAN make a difference. Different hull, different design. How wide is your hull and how wide is his? Total wetted area will make a significant difference in top speed.

A higher pitched prop may not be the answer: It will only help top speed if the engine can swing it at the same RPM or the engine rated RPM.

As you said, first try new or cleaned plugs in addition to setting the points if your engine does not have electronic ignition. Also check or replace the fuel pump and clean the carb.

 

[impatico]

Re: why wont it go FASTER!!!

I think you guys are all wrong. Sometimes it's easier to make the other guy slower, take a hammer to his prop or something lol

 

[dazk14]

Re: why wont it go FASTER!!!

my modle came with a 9.5 X 10 or a 9 X 11 which would be the faster of the two?

and with this; is the 1st number the pitch or the diameter?

1st number is diameter, 2nd is pitch. You will select based on pitch. Is either prop cupped?

Let's keep this simple... Has your rig ever run faster?

Have you had a tach on your boat and checked wide open throttle(WOT) RPM. How about comparing GPS top speed between propellers?

Do you have a doel-fin or such?

How far is your tilt pin out? 1st out of 5 for example. Typically, the further out will yield less boat wetted surface and higher Top speed. But, eventually, the boat will take longer to plane (nose high), porpoise, and ventilate the prop (i.e. spinning , but no thrust).

With a quality set-up, you should be able to reel him in - unless he's done all the tricks as well.

So, Try your props, work your way out on the trim and ideally return with WOT RPM's and GPS readings.

iboats sell's a nice Solas 3 blade cupped stainless prop @ $118 that gives a boost over the stock in every way.

My guess is the 10" will be better than the 11" and probably the 9" stainless Solas might be ideal for best all-around.

I think 23/24mph is doable.

 

[steelespike]

Re: why wont it go FASTER!!!

Is the 04 a 4 stroke?I think the 4 strokes are more sensitive to poor prop selection.
Is the prop in excellent condition?Check the height.Be sure the throttle opens all the way.
Have you carefully adjusted the trim. Does the boat get up on the water and run with about the rear 1/3 in the water.
Is the bottom clean and smooth?

 

[all duck'd up]

Re: why wont it go FASTER!!!

stepping up in octane will end up being worse if your engine isn't designed for high octane, the octane rating represents how resistant the fuel is to self igniting under compression. The higher the octane the more garbage like ethanol (not to say it will be ethanol) they put in the fuel. the only good thing about higher octane fuels is that most of them come with more cleaning additives in them

with it being a 04 im almost sure it will be ok to run 93

 

[all duck'd up]

Re: why wont it go FASTER!!!

You are holding on to your Johnson too tight! And ask any woman: Six inches makes a difference! LOL

Seriously, these tin boats and these small horsepower engines are sensitive to loads. How heavy are you compared to your friend? How much load are you carrying compared to him? How is your engine set on the transom compared to his? Is the anti-ventilation plate even with the bottom or slightly above it?

AND, six inches CAN make a difference. Different hull, different design. How wide is your hull and how wide is his? Total wetted area will make a significant difference in top speed.

A higher pitched prop may not be the answer: It will only help top speed if the engine can swing it at the same RPM or the engine rated RPM.

As you said, first try new or cleaned plugs in addition to setting the points if your engine does not have electronic ignition. Also check or replace the fuel pump and clean the carb.

haha that was a good one!!!

1. he is about 210 and I'm around 250.
2. he is a big time fisher so he always has more stuff in his boat. his dry box is PACKED!!! mine not so much
3. as for our motor setup on the transom i have my (i think its called a trim pin... not sure) its set in the very 1st hole closes to the transom. not sure how his is set up, ill sneak a peak next time he passes me lol
4. as for a anti-ventilation plate i have no clue what that is so......

5. both are semi-v 38 inches wide

6. i put in a new set of autolites last night the old ones were TOASTED! and rusted from the prev owner running it in salt water the boots had a build-up in them also kind of like battery tabs get. so i cleand them out and put contact jell in also.

no clue how to set points so ill have to check that out on youtube or something

 

[all duck'd up]

Re: why wont it go FASTER!!!

I think you guys are all wrong. Sometimes it's easier to make the other guy slower, take a hammer to his prop or something lol

i thought about this but i think he would be pizzed after just buying that prop haha

 

[all duck'd up]

Re: why wont it go FASTER!!!

1st number is diameter, 2nd is pitch. You will select based on pitch. Is either prop cupped?

Let's keep this simple... Has your rig ever run faster?

Have you had a tach on your boat and checked wide open throttle(WOT) RPM. How about comparing GPS top speed between propellers?

Do you have a doel-fin or such?

How far is your tilt pin out? 1st out of 5 for example. Typically, the further out will yield less boat wetted surface and higher Top speed. But, eventually, the boat will take longer to plane (nose high), porpoise, and ventilate the prop (i.e. spinning , but no thrust).

With a quality set-up, you should be able to reel him in - unless he's done all the tricks as well.

So, Try your props, work your way out on the trim and ideally return with WOT RPM's and GPS readings.

iboats sell's a nice Solas 3 blade cupped stainless prop @ $118 that give a boost over the stock in every way.

My guess is the 10" will be better than the 11" and probably the 9" stainless Solas might be ideal for best all-around.

I think 23/24mph is doable.

1. no i just bought the motor 3 months ago all ive done is change the foot oil add some sea foam and some synthetic oil mix insted of the crappy oil that the guy gave me when i bought it, it smoaked way to much for my liking.

2. no to the tach, and gps is how i got the top speed; i only own the 1 prop thats on it now

3. no i done have a fin on it i thought those where to help it plane out faster, my boat planes out pretty quick.

4. it is in the 1st hole closes to the transom. i will have to try this out....

5. so cupped is the way to go??? what about these 4 blade props everyone talks about whats up with them?

 

[all duck'd up]

Re: why wont it go FASTER!!!

Is the 04 a 4 stroke?I think the 4 strokes are more sensitive to poor prop selection.
Is the prop in excellent condition?Check the height.Be sure the throttle opens all the way.
Have you carefully adjusted the trim. Does the boat get up on the water and run with about the rear 1/3 in the water.
Is the bottom clean and smooth?

1. it is a 2 stroke
2. the prop has a small ding on all 3 blades nothing serious and the paint is pealed so the alum is a pitted from being in salt water. i was thinking about sanding it down a little and re-painting it but it would probably knock it off balance knowing my luck
3. all it has is a trim pin and no i havent messed with it. i would say about half of the boat is out of the water a full throtle.
4. yes the bottom is like factory with fresh green paint (recent camo job)

 

[RogersJetboat454]

Re: why wont it go FASTER!!!

with it being a 04 im almost sure it will be ok to run 93

You may be able to use 93, but that does not mean it's the best for your engine.

Between folk lore, misinformation, and gas companies trying to sell more expensive fuel, the average Joe believes that higher octane fuel is better fuel that makes their engine more powerful. This is simply not true....

Octane is a measure of how quickly the fuel burns during the combustion process. The higher the number the SLOWER the burn. You may ask, OK, so why do high performance engines require high octane fuel? Well, because high performance engines are usually high compression engines meaning they generate higher cylinder pressures which in a nutshell means MORE HEAT. With this higher heat present, the average 87 octane fuel can burn too quick and cause a phenomenon known as detonation. Detonation is bad news, and an engine with detonation regularly occurring in it's cylinders will be ruined in a short period of time. This is why higher octane fuels exist. They burn slower, allowing the combustion process in a high compression engine to occur normally.

Your engine on the other hand is a low compression engine, and using a high octane fuel in your low compression engine may slightly hinder it's performance, because the fuel will be burning slower during the combustion process than intended.

 

[RogersJetboat454]

Re: why wont it go FASTER!!!

6. i put in a new set of autolites last night the old ones were TOASTED! and rusted from the prev owner running it in salt water the boots had a build-up in them also kind of like battery tabs get. so i cleand them out and put contact jell in also.

no clue how to set points so ill have to check that out on youtube or something

Personally, I would ditch the Autolites for Champions. Champions are the manufacturer recommended plug for this engine. Also, don't trouble your self with looking for or adjusting the points, it doesn't have any. Truth be told, points haven't been present on a J/E 15 horse since '76...