Lower unit heavy duty or standard

[hornytoad]

I have a 1968 65hp evinrude serial number E05334 model number 65853B can anyone tell me if lowerunit is standard or heavyduty thanx in advance

 

[racerone]

If the bottom half of the gearcasen is held on with about 10 screws or so it is the heavy duty unit.---------Same as used on the 58 / 59 model 50 hp.

 

[hornytoad]

Thanx racerone for the reply! My bottom half of lower unit has 4 bolts on each side for a total of 8. I take it that makes it a standard . am i correct in this assumption?

 

[racerone]

NOPE------The very bottom half of the lower unit , also called the skeg.-----How many bolts if any ???-----OR look up the 59 model 50 hp gearcase and compare that to yours.----Or post a picture I could then tell you in about 1/2 a second what you have.

 

[F_R]

Standard model is slim and has a pointed nose. Heavy duty model looks more like a small football

 

[F_R]

No Title

Standard model is slim and has a pointed nose. Heavy duty model looks more like a small football

 

[F_R]

No Title

That didn't seem to work, trying again

 

[hornytoad]

I tried posting a photo but couldn't. I see the diffrence in the two photos and mine is a standard with no bolts. It is one solid piece with the pointy nose. Thank you all that replied. Love this forum! Lots of helpful people again i thank you all!

 

[jimmbo]

65hp @ 5000 rpm. WOT range 4500 - 5500. 23:20 gear ratio. Prop selection very limited. 10 X 9 1/4 is most likely the prop you will need. Motor shipped with a 9 1/2 X10. Other props that might be found used; 10 /14 X 10, 10 X11, and 10 X 12.

 

[F_R]

Actually, we had the best luck with the 9 1/2 X 10 on the average boats the motors were likely to be used on. Good simple motors.

 

[jimmbo]

My only experience with the those props was on an Evinrude Sweet 16 with a 65 90hp. The 10 X 9 1/4 gave the same top speed and rpm as the 9 1/2 X10 but it had a better holeshot. Even with the 23:20 gearing the 200rpm/in pitch change yardstick still held, when I used the 10 X 11 the rpms dropped 400. I have seen quite a few 10 X 9 1/4 on ebay, but no 9 1/2 X 10s. iboats prop selector is of no use for these old V4s, seems to think they used props ranging 13 - 25 in pitch

 

[F_R]

I kind of regret saying it was a simple motor. That was the year they put that durn battery CD ignition system on it. OK, the 1967 was a good simple motor.

 

[jimmbo]

It was almost a half century ago

 

[jimmbo]

Here is a Prop chart for the V4 80hp. since all the V4s from 1960 - 1968 with standard gear case had the same 23:20 gearing, with exception of the 100 hp, the rpm to mph ratio would hold true for any of the V4s with a 4000 - 5000 rpm range. For the 1968 65 and 85 hp the shaded areas need to be move upward an extra 500 rpm. Boat sizing won't be accurate for anything but the 80hp. Image will get bigger if clicked on