1985 Suzuki 85hp woes

I have recently fitted the engine to my boat and tried to get it running. I first saw the engine last summer and the previous owner showed me it starting and running and although it was only in his yard with muffs it seemed sweet enough. I bought the engine early this year and it had not been winterized This last weekend was the first time that I have tried to run the engine and I did'nt have much luck. I can get the engine to start and run but it has a fairly regular missfire at idle. If I put it in gear and open the throttle the rpm picks up nicely however it still has a regular (every 1,5 seconds) missfire. Most worryingly though when I shut the throttle the engine continues to run on at the same speed. I have at this point turned the key to off which did nothing before pulling the kill cord which also did nothing (manually used the choke to kill it). Now this does not make any sense to me as no throttle open should mean no air?! I suspect that the carbs might need a clean to cure the missfire, however, the engine running at speed with the power and kill-switch off has me baffled. If it is running at idle both the key and kill switch will stop the engine.
Any ideas.

Thanks
Dave.

Re: 1985 Suzuki 85hp woes

Make sure you are running off of fresh gas and give the carbs a good cleaning. See what happens with your other issues after doing so. Good Luck!!

Re: 1985 Suzuki 85hp woes

The only other time I heard of a motor that would not turn off was in this thread and it still does not make any sense to me. Unless the kill circuit is not grounding properly. http://forums.iboats.com/showthread.php?t=385384

Re: 1985 Suzuki 85hp woes

I had the same issue with a 85hp and I know this is and old thead but I cleaned the exhaust ports and had no more problems. Carbon build up was letting engine diesel or run backward.