onebohemian
Seaman Apprentice
- Joined
- May 19, 2003
- Messages
- 43
I've got an '87 Crestliner 17 foot fish/ski with an '87 Evinrude 90 horse V4 on it. Has been this set up since the prior owner purchased it new. Has had a stainless steel prop and hydrafoil on it for over 15 years without any problem. Not sure what prop brand or size is. Prop has some nicks and shows some wear but doesn't appear via sight inspection to have any bends or other problems with its pitch, etc.<br /><br />Had the boat out for walleye opener a month ago and it ran great. Got up on plane no problem just like all the years before. This weekend had the boat out for bass fishing and experienced my first problem the prop seeming to spin out or lose bite from the water when accelarating to get it up on plane. She would try but then the motor would race and the prop just wouldn't grab the water to push the boat. I'd immediatley idle down and slowly start out again. Helped a little trying to start out slower but it was hit or miss. Calm water was also better than the white capped water we had all day Saturday.<br /><br />From reading this list, my first concern was that the prop might be spinning on the hub. I scratched the hub and prop with a line and ran it again. The two marks stayed lined up with one another so I don't think the hub is spun. I've got to believe I'm having some type of cavitation or ventilation problem where the prop is simply loosing its bite on the water. Question is why?<br /><br />As I re-read my OEM and Seloc manuals last night trying to find some explanation of cavitation, the Seloc states that cavitation is a constant problem for boat and prop manufacturers to worry about. It also states that one needs to be very careful so as not to mount fishing or livewell components, etc. too close to the line of water in front of the prop. That got me thinking.<br /><br />In an attempt to reduce the amount of weeks and lake gunk that are sunked into my live well, I added one of those screw-on stainless steel filters to the end of the intake tube. The intake tube is mounted in the bottom back of the boat just to the left of the drain plug, which means its just off center of the line for the prop (although the prop runs lower). I didn't cut the intake pump tube shorter and mount the filter flush against the boat. I instead just screwed the filter on to the tube, causing the tube to protude about three inches and then have the 2 1/2 inch diameter filter stuck on the end of it. <br /><br />My gut now tells me that I may have created a cavitation problem by adding this filter to the intake tube. (I hope this is the problem.) I'm surprised that the water next to the prop is so delicate a system that I could screw it up just by adding a 2 1/2 inch filter but it wouldn't surprise me. Can't get the boat out to run it without the filter on so I'm posting this to see if anyone has any comments or similar experiences to report to make me feel more confident in my possible solution. Any thoughts would be appreciated, even if they are that I'm nuts to believe this could be the source of the problem.<br /><br />Thanks, <br /><br />Mark<br />Minneapolis