Mariner Troubleshooting

[Masonmoore]

Hi, I was hoping to get some ideas from a few people about my mariner. When I bought it, I was told it didn't run and had ignition problems. I managed to fix the ignition problems and got it to run. But it runs very rough. At idle the motor shakes pretty bad, and it seems to rev up and down constantly on its own. Ive determined it has spark on all cylinders, and it's getting plenty of fresh gas. I was told to clean the carbs. Cleaned and rebuilt the carbs, still the same problem. Although, I havent put new plugs in it and the timing has not been set. Also, at full speed on the lake, it does the same thing as it does at idle: goes from a low rpm to a high rpm and back while keeping the same speed.

Any suggestions would help a lot!!
Thanks, Mason

 

[racerone]

Is this a 6 hp or a 200 hp motor ??

 

[Masonmoore]

racerone it is a 1983 80 horse. 6 cylinder