New to boating, I have had very few problems, just replaced starter motor and that's been it. Today I took the boat out and I could not get on plane and with Throttle wide open could not get past 3500 rpm's. Any help would be appreciated.
welcome aboard. I'll start with a Smart a$$ comment just because I can.... Did you have the boat off the trailer?
Okay, now that that is out of the way... how has the boat run on previous outings? Did you have the trim all the way down, or was it still in the position for after you're up on plane, or even on the trailer? did the boat dig a hole and go bow to the sky and just sit there, or did it plow through the water? Fresh gas, clean spark arrester? Prop or props in good shape? lobster pot line wrapped around the props?
Beer makes you feel the way You should feel without beer.
Boat has run great on previous outings, never had a problem getting on plane. Trim down and would come on plane fairly quickly, I would trim up once on plane. I just got the boat out of the shop, had to replace the starter, this was the first day I was able to take the boat out since getting it back. Clean gas, I always add a 1/2 bottle of additive to every fill up. Bow just sat there never coming on plane and plowed through the water. Checked props nothing wrapped around and in good shape. Liked the Smart a$$ comment.
It could be many things, but since you just got it back from service, I would check all the spark plug wires make sure they are all attached, and make sure they are going to the correct cylinder. I have had mechanics pull plug wires off and not realize they did that when they are working on cramped quarters.
Perhaps the failed starter was a symptom of the real problem. Did you happen to strip a gear in the starter? That's a pretty common issue with the modern planetary gear starters if the engine hydro-locks. If the engine hydro-locks, it could be because of a failed exhaust flapper that let water up into the exhaust ports when slowing down too suddenly. Parts of that failed exhaust flapper can end up downstream in the exhaust system causing a blockage that limits horsepower exactly as described. Shine a light into the exhaust outlet, if possible, and see if there's a foreign object. Might need to pull the drive to do a proper inspection. Assuming your engine has exhaust flappers, you need to pull the exhaust elbows to inspect those.