Just picked up an 83 Johnson 200, recently rebuilt, great compression, new power packs and coils. On the trailer with the ears connected for water, you can click the key and it fires right over, and idles fine. I put the boat in the water and it is very difficult to start. The first time I did get it to start I had to turn the idle way up to maintain an 800rpm. Once I did that it idled fine, but is still very hard to start, tried choking the heck out of it, sometimes that helps, but it takes about 10 minutes every time its cold to get it started, once it starts it is fine. Can the back pressure on the exhaust with the engine in the water be causing it? Any suggestions appreciated Mike