yam 115 4 stroke?

[keyks42]

I have a 17ft crestliner with 115 yam, What is the proper rpm I should be running. With 2people in the boat i'm getting just over 5000? I know this ? has been raised before but any feedback would be great.
Thanks
Mark

[klbowe]

5000-6000 RPM at WOT per Yamaha.com.

[cd3]

6000 being the red line, if u will for that motor,so for max performance and speed you prob should be at 5700-6000. i hv that same motor..you could probably change props till you find the best 1 for your purposes.

[klbowe]

You may also consider taking the boat to a "GOOD" shop to make sure the in dash tach is calibrated correctly before trying differnt props.

The tach in my Lund was off 1300 RPM when I purchased it new. This made it very difficult for me to select the correct prop because I was making decisions based on false readings. It also did not help matters that the LARGE boat dealer "Mounts all outboards as low as possible" their own words. After I raised the motor and had the Tach calibrated the prop pitch that came with the boat ran about 5600 a WOT.

Mercury has a propeller selection program: http://www.mercurymarine.com/prop_selector
that will get you pretty close to the prop you need or let you know if you have the correct prop.

Make sure your gauges are correct, your motor is mounted at the proper level and that you have the motor trimmed properly when reading the tach. Then try a new prop.

Best of Luck !

[cd3]

your tach was off that much? 1300 rpm,, ya i guess id hate to stear some1 wrong,,if hes reading 5000 ,,curious,, did yamaha fix your tach free?

[klbowe]

I did not bother Yamaha with it because the calibration is done at the Tach to match the motor so I think it was more of a dealer setup problem or lack of setup.

I suppose it is possible that when you build a boat you simply slap on a motor on the back and throw a tach in the dash and they should work together with out adjustment but then why are they adjustable?

After reading a bit and getting good advice off this Forum it did not take me long to decide that there were some serious setup issues with the boat. I lost faith in the dealer fixed what I could on my own and paid a shop to do the rest.

[Northlander]

I have a 115 on a 17ft Explorer and Im running 5500-5700 rpm at 43-45 mph. 23 alum prop.

[cd3]

i guess were not supposed to bring up the dealor name in this forum are we,glad mine is working just fine.i hope keyks42 gets his working fine also, i think its a great motor.

[keyks42]

Everybody thanks for the info
Mark

[cd3]

message to northlander,, just curious,your lund explorer, u have a 115 on, i thought that boat was only rated for a 90 hp..by the way i fished your favorite place last sunday and monday,, kinda slow thow only a few fish caught

[wayner]

The Lund brochure states that the 1700 explorer single console is rated for a 90. But if you go to the specs page in the back it says 125 HP. I had a dealer also tell me 125. I think the 90 was a misprint.

[cd3]

that seems right i guess,i hv the 1700 fisherman and its rated for the 150.