J
Jerald
Guest
"I'm posting this for a co
"I'm posting this for a co worker, here is his synopsis.
Per our discussion, following is a brief history and synopsis of the recent problem with my boat.
Model 1974 70 HP, 3 cylinder, Johnson motor on a 16' ski boat--Del Magic.
When running properly, the boat will top out at about 37-38 MPH.
I should probably say that it hasn't been run much in the last 3 years.
I had a tune-up 2 weeks ago.
Took it out, would run smooth when idling, but could not get up any speed, 9-10 MPH, barely enough to show on the speedometer.
Took it back to the mechanic. He did some more work on it, took it out and said it ran OK.
We took it out last Saturday and it started very easily and ran smooth while idling.
Puttered away from the dock, got clear of the no-wake zone, firewalled the throttle and after few minutes, topped out at 27 MPH.
I stopped and started it again and it picked up a little better, still not enough to pull up a skier.
Stopped again and restarted. Slowly came up to speed and then all of a sudden, sped up to 39 MPH. Really ran smooth.
I ran it up and down Dog River for 2-3 miles. Stopped again and restarted. It came up to this same speed (39 MPH) again.
Stopped, tried to get up to speed again. Never could get it over 25-26 MPH.
Got disgusted, put it on the trailer and went home.
According to the papers with the tune-up, plugs were replaced, carburetors were cleaned, compression checked OK, synchronized, and replaced the small green round item for the middle cylinder. I think this item has something to do with the electrical/wiring system, but not sure."
"I'm posting this for a co worker, here is his synopsis.
Per our discussion, following is a brief history and synopsis of the recent problem with my boat.
Model 1974 70 HP, 3 cylinder, Johnson motor on a 16' ski boat--Del Magic.
When running properly, the boat will top out at about 37-38 MPH.
I should probably say that it hasn't been run much in the last 3 years.
I had a tune-up 2 weeks ago.
Took it out, would run smooth when idling, but could not get up any speed, 9-10 MPH, barely enough to show on the speedometer.
Took it back to the mechanic. He did some more work on it, took it out and said it ran OK.
We took it out last Saturday and it started very easily and ran smooth while idling.
Puttered away from the dock, got clear of the no-wake zone, firewalled the throttle and after few minutes, topped out at 27 MPH.
I stopped and started it again and it picked up a little better, still not enough to pull up a skier.
Stopped again and restarted. Slowly came up to speed and then all of a sudden, sped up to 39 MPH. Really ran smooth.
I ran it up and down Dog River for 2-3 miles. Stopped again and restarted. It came up to this same speed (39 MPH) again.
Stopped, tried to get up to speed again. Never could get it over 25-26 MPH.
Got disgusted, put it on the trailer and went home.
According to the papers with the tune-up, plugs were replaced, carburetors were cleaned, compression checked OK, synchronized, and replaced the small green round item for the middle cylinder. I think this item has something to do with the electrical/wiring system, but not sure."