1962 evinrude fastwin on a 1236 aluminum john boat motor height.

[Chrisham]

The cavitation plate sets 2 inches below the boat bottom
It seems to take to long to plane out .It has a 2 blade brass prop.Does the motor need raising

 

[Chrisham]

Correction the motor is a 1962 model

 

[jbcurt00]

Correction the motor is a 1962 model

Corrected title to 1962

Yes motor needs to be raised

 

[racerone]

The 18 HP motor should make a 12' boat fly at 25 MPH.-----Are you sure motor is in good condition ? ----Properly adjusted carburetor ?----Running on both cylinders?

 

[Chrisham]

2 inches?

The 18 HP motor should make a 12' boat fly at 25 MPH.-----Are you sure motor is in good condition ? ----Properly adjusted carburetor ?----Running on both cylinders?

Yes sir runs fantastic .cranks first pull and idles fantastic.Just got her running with your help.It will get fast but takes a while to get there.I was wondering if the low cav plate is plowing making it hard to get planed out

 

[racerone]

Maybe try a regular 3 blade prop with 10" pitch.---What pitch is the 2 blade prop?

 

[Crosbyman]

Q:? was is the boat rated for...18hp on a 12 footer sounds likea flipper to come

 

[airshot]

Raise motor until cav plate is same height as boat hull....is cav plate level to boat hull, use long straight edge to check. How is motor trimmed ?
What is compression on both cylinders ? Why a two blade prop ? You need a tach to get real readings in motor performance.

 

[racerone]

Barn find motor likely came with the 2 blade ?-----Popular option in the 1960's I think.

 

[Chrisham]

Q:? was is the boat rated for...18hp on a 12 footer sounds likea flipper to come

Rated for 15 hp .I have run a 1972 25 hp on it a lot and it will move

 

[Chrisham]

Barn find motor likely came with the 2 blade ?-----Popular option in the 1960's I think.

Estate sale and yes the prop was on it

 

[Chrisham]

Raise motor until cav plate is same height as boat hull....is cav plate level to boat hull, use long straight edge to check. How is motor trimmed ?
What is compression on both cylinders ? Why a two blade prop ? You need a tach to get real readings in motor performance.

The cav plate is 2 1/4 inches below the hull.Compression 112 both cylinders cold.Motor was trimmed all the way down

 

[Chrisham]

The prop came on the motor.I bought it at an estate sale out of a barn
SHE IS A GEM EVEN LOOKS GOOD

 

[Chrisham]

Maybe try a regular 3 blade prop with 10" pitch.---What pitch is the 2 blade prop?

I have no idea.Its a cool looking prop

 

[racerone]

If your " cool looking " prop has too much pitch , then acceleration will be slow.-----Have you adjusted carburetor mixture screws for proper performance , yes , no or no idea how?

 

[airshot]

The cav plate is 2 1/4 inches below the hull.Compression 112 both cylinders cold.Motor was trimmed all the way down

Is the motor a long shaft mounted on a short 15" transom ? Pics may help us figure your issues...

 

[Chrisham]

If your " cool looking " prop has too much pitch , then acceleration will be slow.-----Have you adjusted carburetor mixture screws for proper performance , yes , no or no idea how?

I set them at the factory settings .No I have not reset them.seems like motor is doing good great starting and idling for sure

 

[Chrisham]

Is the motor a long shaft mounted on a short 15" transom ? Pics may help us figure your issues...

I think it's a short shaft motor I'll get pictures tommorrow

 

[Chrisham]

N

I set them at the factory settings .No I have not reset them.seems like motor is doing good great starting and idling for sure

Ot sure how to adjust high speed

 

[Chrisham]

Is the motor a long shaft mounted on a short 15" transom ? Pics may help us figure your issues...

The boat transom is 16 inches.on the motor bottom of the mounting bracket to the top of the cavitation plate is 18.I also measured a 72 25hp johnson a 15 hp johnson and a9.5 hp johnson all appear to be 18 inches.I also measured a 30 hp johnson and it's 22.So I assume it is a short shaft