[berk1402]

I just bought a mariah talari 200 with a 5.7 merc. want to go to 4 blade prop. What pitch should i use?

[indykoch]

I think a 21 pitch 4 blade would work great with that set-up. The 5.7 has enough torque to push it, otherwise I would think about a 19-20 pitch.

Do you have "hard numbers" of the current condition (RPM's at full throttle, size of current prop, etc)?

[berk1402]

all I know is the prop on it is a 19p 3-blade. did not seem to have the power it should to me. We will be pulling skeeiers

[mikeyt]

A 19" pitch prop with that 5.7L in a 20' Talari should have you jumping out of the water faster than a flying fish! I think you would be well served to make sure the engine is in good tune first & producing the power its capable of.You should also have the current prop checked to see if the hub is spun (ie slipping). Indy's right, the 21" - 4blade should work just fine on your boat . If you really want to change to a 4 blade then i would recommend a 20" pitch in Aluminum or a 21" pitch in SS but suggest you check for other problems first.

If the engine & current prop check out & you need further advice, we need your RPM's at WOT and your top speed with your current prop. Your engine puts out 250hp and ideally you should hit approx 54-56mph at top speed & your WOT rpms should be somewhere between 4400-4800.

[berk1402]

ok, thanks for the help!

[berk1402]

took boat for test run and @ wot i ran 50mph and 4700rpm did have 5 people in the boat. Does a 20p prop 4blade still sound right ? has a 19p 3 blade on it now. thanks for any help

[mikeyt]

Well, 5 persons on board adds some weight so you could expect to lose a bit off the 'brochure' top speed. 50mph is just a little low and you're right in the recommended rpm range so you wont be able to change things too much. A 4 blade 20" may get you another mph or two with a likely drop of 200 in your WOT rpms. A 21" 4blade will likely drop your WOT rpms about 400-500 and you should gain 2-3mph but you will lose a bit of that low end grunt which might be an issue if you like to haul skiiers, tubers or wakeboarders around. See if you can find a local marine / prop shop that will let you try out a couple of different props. The problem is that you can try out 4 different 20" blades props and get slightly different performances out of each one.

Other things that can be checked if you are confident the engine is in good tune & there is no prop slippage is making sure the hull is clean, you are not overloading the boat with extra gear and the outdrive is properly trimmed at speed. Have you considered adding a pair of Smart tabs? They will help to get your boat on plane quicker (which means you can trim out faster & farther) and keep you on plane longer.