need help with targa

[goombadi99]

2004 tracker targa 16ft
mer 50 2stroke 3 cyl
1400 lbs
wot 5200rpm @23 mph
My question is that the prop on the boat is pretty beat up. And the prop that is on the boat is a 10.5in diameter 13 pitch
Does this seem right? The lower unit has a tag that says gear ratio 1.83x1 ...12x22. does that mean I should have a 12in 22pitch prop on there?
I thought for sure that this boat should do closer to 30 mph. I just bought the boat from the original owner who said he never changed the prop since he bought it new. If I trim the motor up slightly i get 5500rpm but no mph change. Could the badly dinged up prop be the culprit, or the diameter and pitch be compepltely wrong?
Thanks for any help.

 

[steelespike]

Re: need help with targa

A badly dinged prop could hurt performance.If the boat is 1,400 lbs dry weight
thats a load for a 50. 12X22 isn't a prop size but another way to state the ratio.
Based on your rpm the prop is close to what you need.I believe The motor is rasted at 5,300 to 5800 rpm.A good prop will give a truer rpm reading.It is best to prop close to the max rpm.
If its cost effective get the prop repaired and get us the max rpm and speed
by gps if possible.If a prop change is in order you can use the old prop for a spare.
Your antivent(cavitation) plate just above the prop should be
about an inch above the bottom of the boat.With a good prop; raise it a hole at a time to a point just before venting(cavitation) becomes a problem.
If you can gain a couple of inches you might get 1 or 2 mph.
Doesn't sound like much but could be the difference between getting on plane with a load and not.Also an increse in speed generally nets an increase in mpg.