[elimont]

Ive had the boat out the last few weekends. I have had this boat since last summer and cleaned and rewired and done tons of work most not needed but only got it out the past two weekends. Having only experience with jet boats in the past I knew it would plane different than they do. Ive read putting smart tabs and changing to a 4 blade prop makes a world of difference and will be projects for the off season. However here seems to be whats happening. When going from a dead stop I give it about 85% throttle and the bow goes up and for lack of a better way of explaining it feels as if im spinning my tires. The water churns and it raises up but doesnt really go forward for a second or two. I am fully trimmed down at that point. Once it goes forward it takes a second or 2 more to start to even bring the bow down. If I shift wife and kid "neither heavy" to front it planes much faster but still takes im guessing 4-5 seconds to plane. In the time it takes to go from stoped to on plane the bow is so high I have to stand to see anything other than sky. I installed a new ignition system and it is timed correctly. The engine runs very well and once the boat planes out it goes well through the water. Tops out at 44mph based on the gps unit at 4500 RPM. At this time it has a SS 21pitch prop. This may well be how a 18ft boat running on a 4.3 acts. I am a newb and still getting use to this boat. Sorry for long winded explination.

[mikeyt]

hi Eli

You have answered your own question for the most part. That 21" prop is a good prop for cruising but is usually lousy at low end grunt in this application so you need a prop with a lower pitch. Either a 19" 3 blade or a 20" 4 blade will work well. Both of those props will not only give you much better acceleration & planing ability, they will also increase your RPM's by about 300-400 at WOT which will get you right on the recommended max of 4800 for the 4.3L. And both of these props should keep you right in the mid 40's at top speed. Installing a set of Smart Tabs (SX version) will be the icing on the cake. Keep the 21" prop as a spare.

[elimont]

Thanks for the reply. I was about 50% thinking it was all prop and the other 50% thinking it just felt wrong and couldnt figure out why it was bow up so high for so long. Having come from a jet boat its a very strange feeling but then again the deep-V is too. Sharp turns leaning so far to the side took some getting use to as well. Loving the boat so far.

[Stutterin_nate]

i have a 17p 5 blade on my 4.3 it hole shots well but i have to watch rpm's because it will top out at 5200 rpm's

[Jgos929]

I just swapped over to a 4 blade 19 pitch a couple of weeks ago after MikeyT made the suggestion and it planes alot quicker now and runs a whole lot smoother. I have an 18' Shabah with the 4.3 Penta.


Switch props and I think you'll be happier.