propulsion probs

[Peterjohninglis]

Have a 25HP 70s i thnk evenrude hand start that works ok at low reves but soon as i power it up it revs high and wont propel through water but ok at lowe reves propels though water ok

[highcountry]

Have you pulled the prop and checked the sheer pin? It sounds like either the prop nut is loose or the pin is sheered. Take a good look at the prop also. If all of that is good then it sounds like you will need to open up the case.

[Peterjohninglis]

took nut off and its on a spline dont see sheer
pin

[highcountry]

it's behind the prop, the front nut holds it in a notch that is in the rear of the prop.

[Peterjohninglis]

it has no pin behind just female spline pressed into prop on male spline on prop shaft

[highcountry]

oops, I guess that I should have read what you said more closely. With the plug wires pulled you should be able to put it in gear and turn the motor over using the prop (make sure that you only turn in in the normal direction) sounds like a shaft or gear problem but try that and see if you can or if by chance the outside of the prop turns and the inside doesn't. Have a friend with a newer motor that the inside was turning because the nut was to loose.

[Peterjohninglis]

seems to be rubber thats between the spline and prop wore out.It has J in circle and 228 its aluminum. 9.2x12 389. Dont no if that helps to figure out year as well.

[highcountry]

Glad you found the problem, as for the year of your motor use the link at the top of the forum it will lead you thru how to use your model number to find out the year of man. You should be able to find one on ebay punch in the specks that you put on here. Good luck