Need help with Johnson GT100!

Good Morning,
I have a 1990 Johnson GT100 Outboard. I'm having a little bit of a problem, it seems to be really cold starting when it starts up If I rev the engine with the neutral idle ajuster lever it starts to run good but as soon as I lower the rpms and try to take off it sputters. Just does'nt seem to like to idle at a low speed. Once I take off it runs perfect with no problems until I hit a no wake zone and have to slow down to idle speed. It runs fine at first but after awhile at idle speed it starts running rough and when I go to take off it sputters and quits unless I stop and rev the engine up in neutral and warm it up. Any ideas on what could be going on? I posted once before with no responses but someone suggested that the thermostat could be stuck open causing the engine to cool down too much at idle speeds. Any help would be appreciated. IF that would be the problem how hard is it to replace a thermostat? I can't find much information on this.
Thanks in advance
David

Re: Need help with Johnson GT100!

That?s how I have to start mine up all the time, w/ throttle engaged half to all the way. I had a Johnson/Evinrude mechanic tell me that taking the thermostat out will not cause any harm to motor only that it may be harder to start in cold weather. I pulled it since here in Louisiana it?s always hot and when it?s cold I'm in a deer stand. Once the motor warms up (5-10min) it starts fine and I don't have to use throttle lever. So in closing, I'm gonna GUESS your thermostat is stuck open.

Re: Need help with Johnson GT100!

T stat is a very easy beginner job. Dont take it out, it was put in there for a reason. Why mess around for like 30 bucks.

Re: Need help with Johnson GT100!

I've put them back in before only to have the engine over heat (only whne I'm on the water all day) and its always due to the fact that when I pull the thermo it's clogged with bits of shell and sand. I'f I could stay out of the 6" deep marsh ponds I would never have a problem hahaha.