1986 70hp Johnson - Lost compression in top cylinder

[Crappie9]

Boat will run but will not plane out. Would this be a valve problem?

 

[rickdb1boat]

Re: 1986 70hp Johnson - Lost compression in top cylinder

Hi Eddie<br /><br />2-Strokes do not have valves. More than likely your lost compression is due to a hole in the piston or blown rings. Both are bad news as far as being cheap and easy to repair. Did this happen quickly or over time?

 

[speed29668]

Re: 1986 70hp Johnson - Lost compression in top cylinder

2 strokes do have valves. They are called reed valves. This could be the culprit but would be farther down on the list. Do a compression check and make sure you have the correct fuel/air ratio, good spark and do a compression check. Let us know how it turns out!