johnson prop question?

[lyncraft_mechanic]

my 1989 100hp johnson is only running around 3K wot at a speed of 40mph with a 19 pitch prop, now if i were to invest in the the same size prop with a 17" pitch would the motor have better performance or would i loose speed and gain rpm?

 

[Dhadley]

Re: johnson prop question?

I'd verify the tach first. Make sure it's the correct one and is set on position 6. It's not likely that you'd only be turning only 3 k and going that fast with that prop.

 

[junior1113]

Re: johnson prop question?

my 1989 100hp johnson is only running around 3K wot at a speed of 40mph with a 19 pitch prop, now if i were to invest in the the same size prop with a 17" pitch would the motor have better performance or would i loose speed and gain rpm?

impossible 19p @3000 rpms with 1.8 gear ratio with no slip would be in the upper 20's. tach is off! cant answer any questions untill this is cleared up and you have a real wot rpm ill bet your right around 5000-5200 with minimal slip

 

[Yama 250 fireman]

Re: johnson prop question?

How the heck do you post a thread on here?

 

[junior1113]

Re: johnson prop question?

might have to regester click start a post should walk through

 

[lyncraft_mechanic]

Re: johnson prop question?

okay sounds good, i did check the tach and it is set on pole 6 maybe it is not the right tach or it's malfunctioning. the tach is a FIARA aftermarket and it is only about a year old.

 

[junior1113]

Re: johnson prop question?

let us know what wot rpm is dont let it go over 6000 if it can

 

[Dhadley]

Re: johnson prop question?

impossible 19p @3000 rpms with 1.8 gear ratio

That gearcase has a 2:1 ratio.