I finally found a motor to replace the aging 1976 55 HP Chrysler on my 16' Sea nymph bass boat. The Chrysler runs perfect, but sure doesn't have much power. I replaced it with a 1991 Johnson 70 HP with power t/t. HOLY CRAP Batman what a difference!!!

I put it in the water this morning and have had a serious case of perma grin ever since. The new motor has gobs of power, runs way quieter, and it even consumes about 1/2 the gas as the Chrysler. The compression on the Johnson is 128# on all three cylinders and I did put a new impeller on before I hit the lake. This thing runs GREAT!! One thing I did though is I scrapped the VRO in favor of pre-mix. When I ran the motor the low oil alarm sounded. Does anyone know how to shut that thing up??

OH yeah, Idid manage to boat & largemouths in the 2-1/2 hrs I spent on the water!!! What a great day!!!!

The pics are after some cleanup, and I put on the new decals that came with the motor

Cool!

Grats on the new motor.

Perma Grin...Hehehehehehe

Enjoy!

That's a nice upgrade! Have fun with it.

The low oil warning just meant you didn't have enough oil in the tank or the float sensor is bad.

To disconnect it, just unplug the two wire plug under the cowl that goes to the tank and unplug the larger 4/5 wire connector going to the VRO.

There is a world of difference between the power of a 3 cyl Johnson and a Chrysler, even when having what they claim to be the same HP. However you almost doubled the horse power and torque with your upgrade so I'm sure you did have an ear to ear grin. Figure the old motor only had about 45 propshaft HP and your new motor has about 75, plus twice the torque, makes for a world of difference in fun factor.

The low oil warning just meant you didn't have enough oil in the tank or the float sensor is bad.

To disconnect it, just unplug the two wire plug under the cowl that goes to the tank and unplug the larger 4/5 wire connector going to the VRO.

Thanks for the advice Way2slow. I actually never put the tank in or connected the two wires. It looks to me like the connector you're  talking about is a 4 wire, up near the flywheel on the starter side of the motor. Does that sound right?

Well let's see a picture!

NO,  that sounds like your stator wires.

Should be near the fuel pump/vro pump.  There are some wires coming out of the VRO end of the fuel pump going to a connector, unplug that one.  Fuel pump it that black thing that looks like a turbo and the fuel and oil lines go to it.

Speed always will put a s----h---i---t eating  ;D on any mans face. Way to go oh to let you know some history on Hp of OB engines... back in the day they would rate them at the engine not the prop. So your Cry 70 was really a 55hp at the prop and your newer Johnson is a true 70 hp at the prop. Have fun and jump to a 115 inline 6 when you get a chance. You will see a huge diff in your  ;D

Well let's see a picture!

OK, here ya go

a 70 hp on that little boat. cool that has to fly. I have a 75hp on a 17'6" sea nymph  and it runs good. mid/hight 30's on gps, & my boat is alot bigger than yours. What's it run? Nice set up.

a 70 hp on that little boat. cool that has to fly. I have a 75hp on a 17'6" sea nymph and it runs good. mid/hight 30's on gps, & my boat is alot bigger than yours. What's it run? Nice set up.

Thanks, I'm guessing 40 or a little over. It runs great, and I'm almost more excited about the power tilt/ trim cause no I can adjust the ride to where its smooth as glass, even on fairly rough water. The boat is rated for a max of 70HP, and I'm quit happy with the performance so I guess I'll stick with this one for a while.

PERMA GRIN!!!!! Doesn't get any better than that.