prop and wot rpm range

[trackeravalanchedc]

hey everybody i got a 1990 200hp johnson outboard it has a 4 blade prop 131/4 x 27 im only getting n the 4000 rpm range and have a terrible hole shot and speed once planned out it also has a planning fin/anti cavitation fin mounted on the motor not real familiar with that may take it off but what is the wot on this engine? and what is the proper prop for it . i have it on a tracker avalanche dc bass boat

i was thinking of going with a three blade in the 21 pitch im not sure though.

 

[rallyart]

Re: prop and wot rpm range

I think the Max RPM is about 6000 so you should be able to go to a 21" pitch instead of the 27" pitch you have on now. That alone will make an huge difference in hole shot. I would try to get the prop close to right before making any other change.
Someone more familiar with that boat should be able to tell you what the normal range for a prop would be as other things could be affecting your speed.

 

[steelespike]

Re: prop and wot rpm range

Near as I can figure the boat is a little over 1500 lbs and rated for 115 hp.
If my info is right your playing with fire.Assuming the motor is healthy and well tuned
At 200 rpm per inch you would need to go to about a 17" pitch to get to 6,000.
Seems a small prop for a 1500 pound boat.At 17" it would perform like it was shot out of a cannon.
Are you sure the motor is healthy?

 

[Dhadley]

Re: prop and wot rpm range

Well, are you sure it's a 13 1/4" diameter? Maybe a 13 3/4" diameter?

Your motor has a rev limiter at either 6200 or 6700, depending on which pack and model 200 you have. You didn't mention a jackplate but we'll assume you have one. I agree to start with the basics - check spark and compression. Make sure the motor is indeed running right.

 

[trackeravalanchedc]

Re: prop and wot rpm range

the boat is rated for 175hp max it had a 150hp merc but it locked up. only thing i know is the 200hp isnt making the speed the 150 did or the hole shot.. i assumed it was the 4 blade 27 pitch prop the old motor had a 21 pitch 3 blade prop i think that is what im gonna try compression in all cylinders is good. thanks!