correct prop

[vipzach]

I finally got the boat running great. I am wondering if I have the right prop on my boat. I have a 1991 18ft VIP V-hull with a 3.0 Alpha I drive. The number on the prop is 14.25R17. My RPM's only seem to get up to 4000. That seems a little low. Thanks for any ideas! Zach

 

[ufm82]

Re: correct prop

There could be any number or reasons why an engine won't get to proper WOT revs, but the prop is a major factor. I wouldn't think a 17 would be too much though- seems pretty inline to me. If you have access to a 15 pitch, by all means try it. But if you are like most people and don't have a storeroom full of props to try, you have to do other things. <br /><br /> Does the engine run properly? No issues, dead cylinders, rough run, etc? Is the boat hull clean, no hooks or other drag-inducing issues? Is the boat overloaded or improperly loaded? Did it plane properly or did it struggle? Is the prop in good condition or is it damaged? <br /><br /> Give us a bit more info and we may be able to help. I would say that the boat should do OK with the 17 though. What is the recommended RPM range for your engine?<br /><br />UFM82

 

[vipzach]

Re: correct prop

The boat runs great, hull is clean, usually only two adults and a 5 year old onboard. It gets on plane pretty easily. The prop is pretty new. The previous owner had put it on right before I bought the boat. It is a Stainless steel rapture prop.<br /> The prop might be correct and I still need to learn how to trim this boat properly when running. I just wanted to get some opinions before the weekend. I will be playing with the trim this weekend.

 

[QC]

Re: correct prop

Have you verified the tach is correct? I'd be surprised if it planed easily if it was off that much in picth.

 

[vipzach]

Re: correct prop

I have never done anything to check the tach. I know when it is idling warmed up it idles around 850 rpm's nice and smooth. It does plane easily though.