bump and grind

[steplift20]

oh boy im so upset
i went out fishing this week[wed] and cleaned up on blues,had a great time BUT, I have to take her to the repair shop
when i put her in reverse and give her gas the motor makes a thumps or bumps i wrote about this before and didnt do anything about it
she still runs but i dont like the sound
also when i first go do and trim uo the engine it make a loudwhining sound like theres air in the system. i filled it up and put the cap on tight but still no good
and i just replaced the steering tube and the steering is great
the thumping sound has me nervous i dont want it to break down i dont know what it could be