1975 evenrude

[Bamfordtransport123456]

Starts and runs fine but when you give it throttle together up on plain it slips how to fix

 

[racerone]

a 9.9 hp or 135 HP ?-----You might try another prop on it.

 

[Bamfordtransport123456]

It’s a 1975 evenrude 15 horse

 

[racerone]

Replace the prop and test run.----Or did you have lower unit off for water pump work?----Checked gear oil ?-----A 15" motor on a 20" transom?----Post as much information as you can,----Nobody can see or hear your motor!