Prop preference

wes_d03

Cadet
Joined
Apr 23, 2014
Messages
9
Ok, first I'm new to the forum and this is my first post. I have a 86 wellcraft 23 nova xl, it has a 5.7 with a alpha one, i bought it have restored and finished the boat, out drive seems to be in good working order as well as everything driveline wise, took it out for the first time, and took it easy for a while, then went to open it up, motor was running strong however it seemed very slow out of the hole and then topped out at 4000 rpm (on gauge) and GPSed it at 35 mph, the prop is a aluminum 3 blade 19p.. I'm confused because I would think I would either have fast holeshot or low topend but not both. I'm thinking a 14 1/8x20 4 blade. Thanks for the help everyone
 

wes_d03

Cadet
Joined
Apr 23, 2014
Messages
9
additionally, I checked every where on the outdrive and was unable to find a serial # anywhere. I found the sticker that says "serial#" but no # on it... Also the boat came with 2 props, the 19p as mentioned above and a 15p. The 15p was way under propped, it was quick out of the hole but reved up very fast with low MPH but do not have the numbers for that prop. to the best of my memory I would say the 15p hit about 4800 rpm at 35 mph (ish).
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,465
Ayuh,.... Run a Compression Test on the motor, it sounds sick,....
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
An 86 motor could surely be a little tired.The suggested compression test is a good start.
When pulling the plugs note the cylinder and condition of each plug.
Check that the throttle opens up all the way, check that the timing is set right and advancing as it should.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,297
if the current 19P is sluggish and the 15P is underpropped, then going to a 20P 4-blade is going the wrong way. you should be looking at a 17P based on that data alone. however with a 19P 3-blade, your boat should explode out of the water and over-rev. I agree with the advise above. start with a compression test. somehow the motor is not delivering power
 

wes_d03

Cadet
Joined
Apr 23, 2014
Messages
9
ok, sorry for the delayed reply, long story short so after some trouble shooting and some tuning, pulled the intake and found alot of metal shavings. So then deided to pull the motor and see whats going on. The person i bought it from mid winter alleged to have rebuilt the motr, yea he may have but i found that he put the motor togethe with a 1/2 impact gun. Everything internal was waaaaaay over tightened, i am now having a very good friend rebuilding the motor in hopes to catch the end of the season as a wedding gift to my wife (August 16 2014) so maybe we can actually get a day out on it.
 

wes_d03

Cadet
Joined
Apr 23, 2014
Messages
9
i will do a thread with the rebuild explaining my scenario from start to finish
 
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