I have a 150hp Johnson, it was working fine for a while we did some trolling low speed like 2mph, then I went to pick up throttle about half way and the motor started to shake like it wasnt wanting to go any higher then my light that says water/temp was red and loud beep so I didnt know what it was slowed down to troll, stopped and fished for about 20 minutes then turned it on and throttled down and it picked up past that doing about 40-50 on the water and it stopped.

Could it be over heating the temp or is it a bad water pump...if this has happened to anyone or if anyone know what it might be let me know please.

sounds like water pump, how old is it?

You description is kinda confusing, what I gather is...

You trolled slow a while decided to move gave it some gas and at appx. 2500 rpm it started shaking and loosing power and alarm went off, you trolled a little more and then tried to get moving again and it ran this time.

When you say it stopped, does that mean the motor stopped running or the shaking/hesitation stopped?

Idling is tuff on a two stroke, not getting a very good burn of your fuel and the oil will accumulate in the cylinders and will build up carbon. I bet you just knocked the soot out of it. I would try to avoid that much idling.

All that idling my have fowled your plugs.

so spark plugs can cause your engine to shake when you pick up speed. I think I will just do a water pump which is an impeller right and do the spark plugs. because the light and a loud beep came from it water/temp light so it has to be something.

How long has it been since the water pump was serviced? You should service it at a set interval, some do it by time, motor hours, or if you have a water pressure gauge you can go that way too. Few take aways... don't wait till your hearing and alarm to service your boat and excessive idling is the devil.