Advice needed with f250 on a adventure 208

Abcmatthew

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Recently re powered my 2007 208 with a 3.3 f250. I am having a hard time getting the prop figured out. Grady's test with the same rig spun a 17 pitch and Acheived 53 mph. I have tried a 17 , 19 and now a 21 pitch which is putting me right at 5800 rpms but I am barley breaking 40mph ? My bottom is painted , no hard top , 30 gallons of fuel , two people. It seems like I am missing something ? I was hoping for 45mph but just can seem to get there. Motor is second mount hole so I could raise the motor if needed ? Any suggestions ?
 

Parthery

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My 208 had a 200 OX66 and it ran 43 MPH so something isn't right here.

Are your observed speeds via the Yamaha speedo on the dash or are they via GPS?

Post some pics so we can see where your motor is mounted...it may be too low. 5800 RPM at wide open is right where you want to be.
 

Abcmatthew

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Thanks for the reply, gps is my speedo, I am picking up the boat today to see if raising motor a bolt hole will help? I will take some pictures also and post. I have to get this mystery solved
 

Fever

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A bit off-topic, so I apologize, but wanted to inquire while we're talking speed, rpm and such on a 208 model.

I've got a 2001 208 Hardtop with a 2004 F225. Thought I read somewhere that red line on this engine is between 5,000 and 6000 RPM. So, I keep it around 4300 maximum and cruise at 31 or so mph. With what I'm reading here, it sounds like I could put the hammer down and go up to 5,000 rpm? Anyone know where I can get reliable info on the recommended cruise RPM for a Yamaha? Thanks.
 

DennisG01

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If you have correctly found that your MAX RPM "RANGE" is between 5K and 6K, that means your "redline" is 6K. There is no one best "cruise" - as it is dependent on many, MANY factors. But a VERY general rule of thumb is somewhere between 3,500 and 4,500.
 

trapper

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Fever, You should take your boat out on flat water and see what your WOT is. You should be close to 6000 rpm. You cannot over rev as the rev limiter will kick in. Make sure you are propped to reach 5800 to 6000 rpm. I run my Yam F200 on my 2006 208 at 4000 rpm cruising and do approx. 26 mph. My WOT with an average load is 5800 rpm You may know all this but though I would bring up the subject as the correct WOT is vital to the longevity of these 4 strokes. Cheers, trapper