Two years ago I bought a 1979 18' stracraft. It has a 1979 Johnson 100 hp javiln on it. The motor worked fine for about 3 months. Then when I was out one day the motor stopped idling properly. In order to start it I had to increase the throttle til it would start. Then keep it there for a while. As soon as I backed the throttle off to place it in gear, the motor died. I found that if I reved it up, them quickly put it into gear. The motor would take off and work fine. At least it sounded like it was fine. As long as I had the throttle above about 1/3 the motor runs fine. when I slow down the motor runs ok at idle for a while but then it cuts out. I took it to a machanic. He said that one of the pistons was broke and that it needed replaced. So I had him replace it. He said that there was no damage and that all he had to do was hone it out and set the new piston and rings. He also said that it was a common problem with that year of motor, that the pistons would crack. He suggested that I replace all of them. It was more money than I wanted to spend at the time. Well when I got it back home and tried it out. The motor did the same thing. I called him and asked him if he checked the idle. he said it was working fine when he was done.
So any how the motor is doing the samething. I increase the trottle until it starts, then place it into gear quickly. And off I go. I find that if I run at 1/3 throttle or higher for a while (5 min or longer) when I slow down the motor idles just fine for about 1min. then it cuts out again. Any help would be appresiated.
So any how the motor is doing the samething. I increase the trottle until it starts, then place it into gear quickly. And off I go. I find that if I run at 1/3 throttle or higher for a while (5 min or longer) when I slow down the motor idles just fine for about 1min. then it cuts out again. Any help would be appresiated.
