9.5 Johnson performance

[younggun]

I have 2 Johnson 9.5s (a 66 and 68) the 66 came on a boat I just purchased and I took it out for the first time yesterday the boat is a 14 foot trihull open floor plan boat with 2 pedestals. The boat weighs about 300 pounds and is about 4 feet wide I also had a battery 3 gallon gas tank trolling motor and me(180 pounds) and a friend(200 pounds). I only got about 4 or 5 mph but don't think I had the motor tilted right. Can I expect much more speed from this motor?

 

[Gus-71]

Re: 9.5 Johnson performance

Hi!

4-5 mph are too low. It should plane with one person. 2 persons 8-10 not planing and 14-16 planing.

Gus

 

[younggun]

Re: 9.5 Johnson performance

I'm goin to try it with the other one and see how it does when I get a chance What do you think could be causing this?

 

[the machinist]

Re: 9.5 Johnson performance

Gus, It seems to me that you are asking a lot to expect a boat this size, weight & load to reach planeing with this motor.

 

[Rick.]

Re: 9.5 Johnson performance

Could be that you're running on one cylinder but I would also try it empty (the boat) with just yourself and see if it improves significantly. Best of luck. Rick.

 

[younggun]

Re: 9.5 Johnson performance

I have Ben ruunning them both in the tank at the house and the 68 seems to run a good bit better. I know the 68 will plane my 12 foot with me and my buddy and duck hunting gear with no problem so now I need to try it out with that one what kind of speed would y'all expect

 

[steelespike]

Re: 9.5 Johnson performance

Its difficult to predict speed. But a healthy well tuned 9.5 should be able to run about 20 mph on a light reasonably fast boat.
Careful weight placement and trim adjustment may help. your at about 858 lbs.a lot for a 9.5 to plane.
Was your speed from a gps? It does seem the motor has an issue.Coil failure is very common and you wouldn't be the first to not realize
you were on one cylinder except for the lack of performance.

 

[nwcove]

Re: 9.5 Johnson performance

there shoudnt be much of a difference between either motor....what are the compression numbers on the "weak" one?

 

[younggun]

Re: 9.5 Johnson performance

The compression is good on both. I think the carb is the problem for the weak one because it sat for several years in a shed. The compression on both is between 70 and 75

 

[younggun]

Re: 9.5 Johnson performance

It does 22 with me by myself in my 12 foot aluminum Jon with nothing else and about 17-18 me and a friend with my 68 that's I have had for a while

 

[younggun]

Re: 9.5 Johnson performance

Took the boat out again Sunday with my 68 9.5 and the motor ran good but only got about 7mph Should I try a lower pitch prop considering the weight of the boat?

 

[Chinewalker]

Re: 9.5 Johnson performance

As noted above - make sure you're running on both cylinders before you start changing props, etc...

 

[steelespike]

Re: 9.5 Johnson performance

what he said.^

 

[bonz_d]

Re: 9.5 Johnson performance

I have a 1969 9.5hp Johnson that I've owned sense 1976 and am the second owner. Have used this on many different boats and I too believe that you are at this ones limit with those loads.

 

[younggun]

Re: 9.5 Johnson performance

It is runnin on boat cylinders and it pushes my 12 foot aluminum about 15 to 20 mph depending on the load