Re: 91 200 johnson will not stay running under load
"also, it runs fine on the hose but when it is in the water, it shows its symptoms... when i first put the boat in the water th e last time it seemed to idle fine for about the first 30 seconds then didnt want to stay running especially in gear.."
Your motor has a system called QuikStart that automatically advances the timing when the engine is cold, then releases the timing when the temperature reaches around 96 degrees or when the engine turns higer than 1100 RPM whichever comes first. The timing and idle have to be set with QuikStart disabled, under load.
I think that what is happening is that your idle is set too low once the QuikStart kicks out. As soon as you drop your warm up lever and try to get in gear the engine would die.
When on muffs, there is no load on the system, not even back pressure, so the motor could seem to run fine on as few as three cylinders.