I've got a 78 Johnson 150. The engine is all original and was never apart. The compression is 110 on all cyls. When I bought the motor it was sitting a while. The thing ran horrible when I got it on my boat. I then took it to a marina and they put new thermostats in it and adjusted the timing where it should have been. This only made a marginal difference. I then took it to another one and they cleaned and syched the carbs. This made a huge difference although there are still some minor problems. The motor seems to load up at idle and low rpms, especially when it is tilted all the way down for some reason. When it is going at throttle it runs great. It also stalls when it is put into gear. What should the idle rpm be set at? Right now it is about 1500 just to keep it from stalling when put in gear. When it is shut off warm it will fire right up great, but when it is cold it is a struggle. It will turn over until a cyl fires and then the starter will immediately kick out. You will end up playing this game a few minutes until it will finally just fire right up. Should the starter be kicking out like it is? Or is this a problem with the tuning? It seems like if the starter would stay engaged until I let off the key it would start fine. The plugs are all new and it is firing on all 6 cyls. The compression is great on all 6. What could the problem be?? I am mechanically inclined. I used to be an auto mechanic. This is my first boat and I am new to these 2-stroke outboards. This seems like a carb problem to me even though they were just cleaned out. Any ideas on where to go next??
