After 6 hours of engine break in of our yamaha 115 on a-2275 FSI, and when I get it up to full throttle - 6300RPMs, the engine starts to bounce or hop. When I decreased the RPMs to 5000, the engine appears to run smooth. The overall gps speed reports 19.4 mphs at both 5000 or 6300 rpms. Does anyone think this is a prop issue due to cavatation? I have the dealer supplied prop. Any thoughts on what size prop is right? Should we be getting more MPH when the rpms go up?
prop issue?
- Thread starter pcvaughn
- Start date
ericscher
Well-Known Member
Your redline should be 6000rpm. Also, that boat should hit 23mp with a 90 horse engine. With the 115, you should get at least 25mp, maybe a bit more. Doesn't sound like much, but it is.
If you're hitting 6300rpm, then first thing that comes to mind is your pitch. You need more, or so I figure.
What are your current prop specs?
Ben & Suzy
Well-Known Member
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I will check out the prop size - problem is my boat is already at the lake - an hour away. While I check that out - does Team Bennington have a recommended prop/pitch size that should be on a 115 and a 22 ft toon? I have the 2275 FSI and Yamaha 4 Stroke. We normally just have the family and the dog - 650+ pounds including our gear.
R
Retired Team Member1
Guest
Please contact your dealer for prop assistance. Bennington provides a prop chart to help guide dealers, as well as performance bulletins prepared by technical personnel from the engine manufacturers; however, the guide is just that...a starting point. Often times, prop sizes must be adjusted due to altitude and a variety of other reasons. It's an art, not a science! (Isn't that what the doctors say?) Seriously though, don't get discouraged. Sometimes it just takes a few tries. Good luck.
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After checking the prop size we have a 13 5/8 X 13 this looks like the problem will take to the dealer and see what they can do.
Thanks