Notices
The Boating Forum

Yamaha F300

Old 05-23-2020, 06:50 AM
  #1  
Junior Member
Thread Starter
 
Join Date: Jul 2018
Location: boston, ma
Posts: 16
Received 0 Likes on 0 Posts
Default Yamaha F300

I have 22 foot hydra sport just hit 3 hours on new Yamaha 300 time to try WOT 40 mph at 5300 rpms
is that where it should be
Old 05-23-2020, 06:53 AM
  #2  
Admirals Club Admiral's Club Member
 
Fish'nFool's Avatar
 
Join Date: Mar 2009
Location: Anywhere but here...
Posts: 25,651
Received 3,020 Likes on 1,603 Posts
Default

What does the performance bulletin say?

Sounds slow for that set up. Are you trimming your motor up to the most efficient angle? Keep trimming until your speed starts to drop.
Likes:
Old 05-23-2020, 07:02 AM
  #3  
Senior MemberCaptains Club MemberPLEDGER
 
Join Date: Nov 2002
Location: Toms River NJ
Posts: 2,030
Received 46 Likes on 33 Posts
Default

Originally Posted by Fish'nFool View Post
What does the performance bulletin say?

Sounds slow for that set up. Are you trimming your motor up to the most efficient angle? Keep trimming until your speed starts to drop.
^^^This^^^
Old 05-23-2020, 07:03 AM
  #4  
Junior Member
Thread Starter
 
Join Date: Jul 2018
Location: boston, ma
Posts: 16
Received 0 Likes on 0 Posts
Default

Thanks I will try that I only trimmed it slightly
Old 05-23-2020, 07:04 AM
  #5  
Senior Member
 
Join Date: Nov 2014
Posts: 4,960
Received 906 Likes on 461 Posts
Default

You should be hitting 5800 rpm or so at Wot.
Old 05-23-2020, 07:11 AM
  #6  
Admirals Club Admiral's Club Member
 
Join Date: Feb 2010
Location: Marathon Fl. (Sombrero Isle)
Posts: 3,337
Received 446 Likes on 306 Posts
Default

That is not right, First of all 5300 RPM's is low unless you are trying to create a motor that will make oil. You should be much closer to 5800RPM's or a tad higher. Now getting there could be several things.

Motor mounting height. Most people post a video of the motor lower unit while on plane. You want the ride plate at the water level. If you motor is to deep it will hurt your speed/fuel economy/ and also your RPM's.

To much prop. Perhaps you have the wrong prop that has to much pitch for your setup.

Motor trim. Typically once on plan at a given throttle level, you start to trim your motor up, Watch the tach and listen closely, The minute you see RPM's start to increase or hear the RPM's increase you are trimmed out good. Thus trim your motor up to gain 100-200 RPM's This will likely help your speed issue but not the RPM range that you should be in.


The last Issue could be your boat condition. If the bottom of the boat had any growth on it, all bets are off. Just leaving it in the water for a week or 2, can hurt your performance. and if you left it in longer and have grass ect growing on it, your doing good even getting that speed.





Likes:
Old 05-23-2020, 07:57 AM
  #7  
Admirals Club Admiral's Club Member
 
Join Date: Aug 2013
Location: Beaverdam VA
Posts: 1,084
Received 510 Likes on 280 Posts
Default

You want to prop so you are @ 6000 RpM light. If loaded heavy as you will be, 5700 to 5800. And run the piss out of it when you get to the point of break in that allows WOT.
When the boat is perfectly trimmed, it will take roughly the same amount of effort to turn the wheel in each direction. When you blast off fully trimmed down, one side of the prop is taking a bigger bite than the other side. As you trim up and propshaft becomes parallel to the water, the steering effort will be very close to equal in each direction as both sides of the prop are taking and equal bite angle.
If that is a new boat (you said the motor was new) it would be going back to the dealer for a lower pitch prop, probably by 2. You need 400 plus RpM.
​​​​​
Likes:
Old 05-23-2020, 08:07 AM
  #8  
Admirals Club Admiral's Club Member
 
Join Date: Aug 2013
Location: Beaverdam VA
Posts: 1,084
Received 510 Likes on 280 Posts
Default

As far as engine height, I have raised the engines on two different boats two holes. Neither made even 100 RpM difference, a SeaPro SV 2100 with F150 and my 2320 Parker with an F 300, both with the AV plate buried at the start. A big fat letdown. I would love to see evidence from someone that wasn't hearsay. No doubt it may raise RpM through additional prop ventilation.
I agree it makes sense, but don't expect 2 mph and .5mpg fuel burn improvements. It's a miniscule decrease in drag vs the drag produced by the hull bottom. Good luck either way.
Old 05-23-2020, 08:09 AM
  #9  
Senior Member
 
Join Date: Aug 2017
Posts: 893
Received 303 Likes on 181 Posts
Default

Originally Posted by Jciampa View Post
I have 22 foot hydra sport just hit 3 hours on new Yamaha 300 time to try WOT 40 mph at 5300 rpms
is that where it should be
Should be a 55mph+. boat at about 5800 or so. Have fun.
Old 05-23-2020, 01:52 PM
  #10  
Junior Member
Thread Starter
 
Join Date: Jul 2018
Location: boston, ma
Posts: 16
Received 0 Likes on 0 Posts
Default

I don’t think I was trimmed properly Could be one issue . I have a 18” pitch x 15 1/4 prop I think I need 19 pitch I called the dealer and he said I was in good range he said it will go up as it breaks in I will test the trim again
Old 05-23-2020, 03:58 PM
  #11  
Admirals Club Admiral's Club Member
 
Join Date: Feb 2010
Location: Marathon Fl. (Sombrero Isle)
Posts: 3,337
Received 446 Likes on 306 Posts
Default

You would loose RPM's by going to more pitch. The raising of the motor can make a sig difference in top end speed.

Old 05-23-2020, 04:35 PM
  #12  
Senior Member
 
Join Date: Jun 2012
Location: Downingtown, PA
Posts: 1,237
Received 286 Likes on 142 Posts
Default

(Need a delete button)
Old 05-23-2020, 05:24 PM
  #13  
Admirals Club Admiral's Club Member
 
Join Date: Sep 2018
Location: CT
Posts: 383
Received 115 Likes on 79 Posts
Default

After 20 hrs or so you will gain a few hundred RPM, thats what I have found from my experience with my F300. Then trim a bit and you might be fine.
My F300 with a 19 hits 5600 rpm @ 47mph loaded up. Light load I have seen 50mph and 5800 rpm. Dealer says fine as Yamaha specs an rpm range from 5600-6000.
I have a Cobia 240.
Old 05-23-2020, 07:50 PM
  #14  
Senior MemberCaptains Club MemberPLEDGER
 
Join Date: Nov 2002
Location: Toms River NJ
Posts: 2,030
Received 46 Likes on 33 Posts
Default

Originally Posted by Jciampa View Post
I dont think I was trimmed properly Could be one issue . I have a 18 pitch x 15 1/4 prop I think I need 19 pitch I called the dealer and he said I was in good range he said it will go up as it breaks in I will test the trim again
Going up in pitch (19") will cause a decrease in rpm's, you want to go down in pitch.
Old 05-24-2020, 04:10 AM
  #15  
Senior Member
 
Join Date: Nov 2014
Posts: 4,960
Received 906 Likes on 461 Posts
Default

Originally Posted by Gmart View Post
After 20 hrs or so you will gain a few hundred RPM, thats what I have found from my experience with my F300. Then trim a bit and you might be fine.
My F300 with a 19 hits 5600 rpm @ 47mph loaded up. Light load I have seen 50mph and 5800 rpm. Dealer says fine as Yamaha specs an rpm range from 5600-6000.
I have a Cobia 240.
Are you sure that you have a 19" pitch prop, and not a 17" pitch? I think those boats typically come with 15.5x17" prop, and your numbers seem to be consistent with 15.5x17" numbers. Or did you play with props and go down in diameter and up in pitch?
Old 05-24-2020, 04:27 AM
  #16  
Admirals Club Admiral's Club Member
 
Join Date: May 2011
Location: Louisiana and Morehead City N.C.
Posts: 12,019
Received 1,094 Likes on 788 Posts
Default

Originally Posted by Jciampa View Post
I dont think I was trimmed properly Could be one issue . I have a 18 pitch x 15 1/4 prop I think I need 19 pitch I called the dealer and he said I was in good range he said it will go up as it breaks in I will test the trim again
The dealer is wrong. Going up in pitch will reduce RPMS. Most of the 24 bayboats like mine use a 19 pitch. The single engine CC boats that weigh over 3000 pounds almost always use a 17 pitch prop.

Correct engine height , trimming properly and a 17 pitch SWS II prop will put you atleast 5800 rpms or more.
Old 05-24-2020, 04:30 AM
  #17  
Admirals Club Admiral's Club Member
 
Join Date: Sep 2018
Location: CT
Posts: 383
Received 115 Likes on 79 Posts
Default

Originally Posted by 6104696 View Post
Are you sure that you have a 19" pitch prop, and not a 17" pitch? I think those boats typically come with 15.5x17" prop, and your numbers seem to be consistent with 15.5x17" numbers. Or did you play with props and go down in diameter and up in pitch?
Yes, 15.25x19, I was concerned at first but the dealer assured me I was good and I asked to have it changed while I had some minor issues addressed under warranty. I even reached out to Cobia and all say Im good. On the first oil change ( I did myself) the oil looked good and the right amount, no more came out. The boat gets on plane good so...
First time out this year, 5 light adultss and normal fishing gear etc... 5650 rpm at 45-47mph.
Old 05-28-2020, 02:29 PM
  #18  
Admirals Club Admiral's Club Member
 
Join Date: Sep 2018
Location: CT
Posts: 383
Received 115 Likes on 79 Posts
Default

Originally Posted by Gmart View Post
Yes, 15.25x19, I was concerned at first but the dealer assured me I was good and I asked to have it changed while I had some minor issues addressed under warranty. I even reached out to Cobia and all say Im good. On the first oil change ( I did myself) the oil looked good and the right amount, no more came out. The boat gets on plane good so...
First time out this year, 5 light adultss and normal fishing gear etc... 5650 rpm at 45-47mph.
As a test run yesterday coming in from the racr through Niantic bay, seas were pretty flat, 5 adults, loaded with gear, ice 60gallons fuel, trimmed motor almost all way up- no slipping, but did throw nice rooster tail- 5850 RPM, 46mph. Motor now has about 45hrs.
Old 05-28-2020, 05:42 PM
  #19  
Member
 
Join Date: Jul 2013
Location: North Carolina
Posts: 51
Received 12 Likes on 9 Posts
Default

I have a 24' HS vector that I just re-engined with a 300 Yamaha. WOT I'm turning 5800-5900 RPMs and 50+ MPH with a light load.

You should be hitting 55+ easily.
Old 05-28-2020, 06:04 PM
  #20  
Admirals Club Admiral's Club Member
 
Join Date: Sep 2018
Location: CT
Posts: 383
Received 115 Likes on 79 Posts
Default

Originally Posted by Phishingfiend View Post
I have a 24' HS vector that I just re-engined with a 300 Yamaha. WOT I'm turning 5800-5900 RPMs and 50+ MPH with a light load.

You should be hitting 55+ easily.
light load Im 50+ Mph in a Cobia 240

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.