V-King/Evinrude Prop Selection

Hi Randy, thanks for helping us all out! I have a V-King that's running a 1983 Evinrude 235, mild work with pistons, lightened flywheel, velocity stacks, nose cone and exhaust relief. I believe I have a 4 inch setback with the hydraulic jack-plate. The engine runs well and the boat really flies (for my experience level anyway). I'm running what appears to be a 30 pitch big ear type merc prop (chopper?) According to the tach, I'm spinning a little over 6k rpms at full chat. As I'm to understand, this is about right for the engine, but I'm wondering if a different prop would help gain a little more on top end? The problems I have are the boat is a little hard to pop out of the hole unless the engine is fully tucked in. Also, I weigh about 180lbs, and if I have a brave passenger along that weighs any more than 140, I can't get the boat up on pad, and it tops out at about 70mph, compared to about 84mph with just me. Any suggestions? What's the difference between Choppers, Cleavers and other types? Thanks!

Rolf Mair

 

Rolf,

Try a small blade (inline chopper) chopper or have yours modified. The ventilation on take off is common with OMC's. A good prop shop can "roll" the leading edge to eliminate this. From your description the boats lack of ability to carry weight might be a poorly shaped prop or a nose cone job that isn't quite right. You should only lose 3-4 mph with the passenger. I'd look at the prop first. You can fix the take off problem and most likely get a faster prop back. Choppers have a lot of parabolic rake as opposed to straight rake. The rake line is kind of skewed. Cleavers are of less blade area and usually less rake. This is why they have less lift. I do have some cleavers with lots of bow lift so that is not a given. Choppers almost always have a ton of lift, unless the prop is flawed. Send yours in I think you'll like the result.

                                                                      Randy

P.S. Make sure you have a nice torque tab on the skeg.

 

 

Please submit whatever questions you have to IHRTechTalk@yahoo.com.  All questions and answers selected will be displayed on this page as they come in.  Note: though all boaters are welcome, priority may be given to I.H.R. members.  Randy can not be held responsible for any advice given.  Though his information and expertise is second to none, he has no control over what you do with your boat.  It is up to you to boat safely and act responsibly, and his advice is only to be used as a guidance for your high performance boat/motor of which you are the one responsible for the risks involved.

Thanks,
Mark C.

 

[ Home l About I.H.R. l History l Models l Registry l Members' Pictures l Feature Article l Tech Talk ]
[ Literature l Events l Top Guns l Guest Boat l Classifieds l Video Gallery l Racing Corner ]
[ Prop Slippage Program l Animated Videos l Screen Savers l HIN Decoder l Links l Contact Mark ]