Johnson 90/65 Opinions?

[handyandy]

Good to hear you like, I bet with some fine tuning, pump, impeller work you'll be able to squeeze some more out of it speed wise. You could probably go up a little higher with the engine with some intake fins maybe?

 

[rotus623]

Good to hear you like, I bet with some fine tuning, pump, impeller work you'll be able to squeeze some more out of it speed wise. You could probably go up a little higher with the engine with some intake fins maybe?

Oh yea! The 65hp impeller is in there now, I need to order the 80hp one.

I may be able to come up a hole with some fins because I didnt cavitate one bit with her. Id like to spend a little time fine tuning her but its flathead season so I may just let her eat for now. Just got a Structure Scan transducer so I can read the shallow bottoms and fine those honey holes!

 

[eshaw]

So did any of you fellas try the 90 Johnson on a 16 foot boat? I have one on my pontoon that I'm thinking of taking off and using on my Alumaweld and putting the Yamaha on the pontoon. I'd like some real world feed back on how they draft on the smaller boats and how much weight you can push with it. My boat is 50 inches wide and all welded. Thanks guys.

 

[rotus623]

Never had that big of a motor on a boat that size. The bottom of this boat is 54", and with me and two other guys back there catfishing she still has plenty of freeboard. I have the start battery, 12 gal of fuel, and another passenger back there and she hops right up on plane and rolls out.

We use it for catfishing. I had a bait tank and livewell on the boat with three batteries, 12 gal of fuel and two OTHER guys and she got right up on plane. She's not as fast as I would like (30-32), but man does she push a load. We were skimming through inches of water while on plane, and had the weight set up to drift 4-5" of water when floating. This motor is one of the lightest, if not the lightest 90/115 that Johnson has produced, at 315lbs for the jet. My 4 stroke 60/40 jet weighed in at 267. So for 50 lbs. more I have twice the HP. That's going from a 1L block to a 1.6L block!!

The 60/40 was on the back of my 1648 .125gauge rhino, with tunnel (heavy). That boat had little to no freeboard with that motor. This motor would have swamped her without pods.

I just got the 80hp impeller and it has been polished up and sharpened. Got her installed with my clearances tight and ready to give her a run. Hoping to get 33-34 out of her.

 

[eshaw]

My boat is a 16 foot 50 inch wide flat bottom. I don't if know I'd have to add pods if I went with the Johnson 90. I think from what I've read on these motors that if I removed the lower unit and replaced it with the jet unit that it would probably add even more weight. Supposedly my 90 Johnson weighs in at 319 lbs.. The 40 Yamaha I have on there now weighs 196 and the kicker is another 96 pounds. Thats 292 lbs. and I figure it's almost a wash or close to it. I could shift some weight forward also, like the gas tank for one. Sounds like your boat pushes a good load. I was hoping that maybe you'd have run the 90 on yours. Thanks for the reply!

 

[rotus623]

What year Johnson do you have? All of the 4 cyl crossflow 90-115's from 1978-1998 weigh 315 with a jet foot. If you have a newer 60 degree it may be more. I wouldn't use a jack plate, but the power lift like I have used as it doesn't add any set back. You want to avoid setback if you can. Worst case scenario you could always add float pods. Just know that with pods the boat effectively becomes a flats boat and you will NOT be able to trim out in say 1-2' swells. You will plow into them.

What hp does the boat call for? Mine calls for 75hp. The motor I have was a factory 90/65 so it pulls up as 65hp at the insurance company. Pretty nice because I have a 115 powerhead on there :lol: :lol:

 

[handyandy]

My boat is a 16 foot 50 inch wide flat bottom. I don't if know I'd have to add pods if I went with the Johnson 90. I think from what I've read on these motors that if I removed the lower unit and replaced it with the jet unit that it would probably add even more weight. Supposedly my 90 Johnson weighs in at 319 lbs.. The 40 Yamaha I have on there now weighs 196 and the kicker is another 96 pounds. Thats 292 lbs. and I figure it's almost a wash or close to it. I could shift some weight forward also, like the gas tank for one. Sounds like your boat pushes a good load. I was hoping that maybe you'd have run the 90 on yours. Thanks for the reply!

That johnson would probably be too heavy, you could however find an old 2 stroke 75-90hp yamaha which might be ok for you. Those big 3 cyl yammies were some of the lightest in that power range. Your other option could be an omc 3 cyl 60-70hp they weigh in around 215 I think and would be a big jump from the 40 yammie. The v-4 omc enignes are well suited to 18-20ft boats. The larger boat also does better with a load it has more hull surface area to displace water and help it get on plane.

 

[rotus623]

Im with Andy, that small of a boat would be much more suited for an inline triple. Would be fun with this ol V4 back there though!! I know that these V4 motors are everywhere and relatively cheap and sometimes free. I like the availability.

Yamaha 75-90 triple.......... Much harder to find. And when you do they are $3500.

 

[eshaw]

What year Johnson do you have? All of the 4 cyl crossflow 90-115's from 1978-1998 weigh 315 with a jet foot. If you have a newer 60 degree it may be more. I wouldn't use a jack plate, but the power lift like I have used as it doesn't add any set back. You want to avoid setback if you can. Worst case scenario you could always add float pods. Just know that with pods the boat effectively becomes a flats boat and you will NOT be able to trim out in say 1-2' swells. You will plow into them.

What hp does the boat call for? Mine calls for 75hp. The motor I have was a factory 90/65 so it pulls up as 65hp at the insurance company. Pretty nice because I have a 115 powerhead on there :lol: :lol:

The Johnson I have is a 2000. I've been playing with the idea of sticking it on there just to see how the boat sets with the engine in place. The boat is rated for up to 70 hp. and I'd prefer to not use the float pods if possible. I guess there's only one way to find out!

 

[handyandy]

Im with Andy, that small of a boat would be much more suited for an inline triple. Would be fun with this ol V4 back there though!! I know that these V4 motors are everywhere and relatively cheap and sometimes free. I like the availability.

Yamaha 75-90 triple.......... Much harder to find. And when you do they are $3500.

That is the reason I don't have one. I'm a fan of the omc triples really good engines as well, funny enough a 56ci omc triple is usually harder for me to find cheap than the v4's just this past weekend I almost bought an old pos bass boat cause the boat, motor, trailer were 600 bucks and it had an early 90's v4 115 johnson.

 

[rotus623]

So I had the 65hp impeller in my pump and she was winding up a little higher than I wanted. I picked up a used 80hp impeller that had been polished and had a little work on it, and shimmed it out .020 off a fresh liner. Hole shot is now at 1.5 boat lengths, rpms came down, and we are running 34mph lake speed!! That's 32 upriver, 36 downriver. I can trim out and gain speed until the splash kicks up.

I am going to put a splash plate on and see how she does. After I do that I will try some intake fins and lifting the motor 1/4-1/2" and see what I can get. For now, she's performing great, but Im going to get the most that I can out of her, little by little.