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Jason
Jason, Marine Mechanic
Category: Marine Electronics
Satisfied Customers: 14295
Experience:  Degree in Marine Technology, Also Certified with Mercury Marine, MCM, MIE, VP, Yamaha, Honda, Suzuki
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I have a 22.5 Bennington Pontoon boat that I just put a new

Customer Question

I have a 22.5 Bennington Pontoon boat that I just put a new Yamaha F150LB outboard on. I did the break in period at Lake Powell in Utah elevation 3,700 ft. I purchased a prop that was recommended on a Yamaha/Bennington test on a pontoon the same size as
mine. It is a Yamaha Reliance SDS S.S. 14 1/2 x 15 prop. The best result that I have gotten was 4900 rpm @ 26 mph. The test even though at sea level was 40.2 mph @ 5900 RPM. Do I need to purchase a different pitch prop for the altitude to get the RPM's up
and the MPH?
Submitted: 1 year ago.
Category: Marine Electronics
Expert:  Jason replied 1 year ago.
Hello my name is ***** ***** am I speaking with? When you say the test at sea level was 40mph and 5900 rpm, was this something you read. Or did your specific boat actually turn those numbers out?
Customer: replied 1 year ago.
This was a Performance Bulletin done by Yamaha and Bennington Boats on a 22'5" Pontoon boat last year with the F150 engine. Performance Data 6000 RPM @ 42.3 mph 5500 RPM @39.2 mph 5000 RPM @ 35.2 mph etc. Test Conditions were
2 people Air Temp 82 Degrees 77 % degree water temp. Elevation Sea Level wind velocity 5-10 mph.
Customer: replied 1 year ago.
This is Greg
Expert:  Jason replied 1 year ago.
Hi Greg. Do you happen to have a copy of that bulletin?
Customer: replied 1 year ago.
Some people have told me to pitch down to 14 1/2 x 13 , 14 x 11 or 15 5/8 x 11?
Customer: replied 1 year ago.
Yes I do have a copy.
Expert:  Jason replied 1 year ago.
Is it in PDF format? Can I see it?
Customer: replied 1 year ago.
Yes I will send it to you.
Expert:  Jason replied 1 year ago.
Okay.
Customer: replied 1 year ago.
I am sorry the + Add Files will not work. Is there another way to get this to you?
Expert:  Jason replied 1 year ago.
On the top left of the bulletin does it say YPB# ***** it someplace, I can look it up that way.
Customer: replied 1 year ago.
YBF # *****+22SSX_F150LA_2014-10-29_PNT
Expert:  Jason replied 1 year ago.
Click this link, this one, yes? http://www.benningtonmarine.com/wp-content/uploads/BNT-22SSX-F150LA-2014-10-29-PNT.pdf
Customer: replied 1 year ago.
yes
Expert:  Jason replied 1 year ago.
Hmm...... ('m going to make 1 quick point here. Performance bulletins done by boat builders are often very "generous". Performance bulletins done by engine manufactors are usually a bit more "real world". And I will give you an example. Look at 4 things. Weight, length, horsepower and speed. According to that bulletin we have1. 24'9 feet2. 3609 pounds3. 150 HP4. 40.6 mph And that bulletin was written by Bennington, not Yamaha. Here are one Yamaha for a very Similar Bennington boat. http://yamahaoutboards.com/sites/default/files/bulletins/bulletin_4stroke_hpv6_gyt3_bnt-2075rli-f150txr.pdf 1. 20'6 feet long2. 3295 pounds3. Same 150 horsepower4. 38.2 MPH top speed So when comparing these 2. A shorter lighter boat of the same build style with the same amount of horsepower should be the faster boat, not the slower boat. There is another thing I want to bring up after this but I wanted to get this out first. Does that all make sense so far?
Expert:  Jason replied 1 year ago.
The next question I have is, is this a new boat, or a new engine? Is it under warranty in any way for you?
Customer: replied 1 year ago.
THis is a 2007 boat with a brand new 2015 motor
Expert:  Jason replied 1 year ago.
On your speed reading that you give me. Is that according to GPS?
Customer: replied 1 year ago.
Yes I used the Speedo and the Lowrance GPS
Customer: replied 1 year ago.
I also checked it with a iphone GPS app.
Expert:  Jason replied 1 year ago.
I've been using prop software and crunching numbers this hole time. For that engine on that boat, at that altitude the speed is about right. I've been playing with it and can squeeze maybe 28mph of it with a high end prop. But.... The rpms of*****to low. And that part isn't fitting into my equations. So what i'm thinking right now is either your tach is off, and not reading correctly. Or the outboard is to low in the water and have to much drag. What I would do next is hook up an inductive tach to a plug wire and run the boat at max rpm and see if that tach reading of 4900 is correct or not. Does that make sense?
Customer: replied 1 year ago.
Yes it does But I am not sure how to do that.
Customer: replied 1 year ago.
I do know that motor is mounted on the #1 hole at the top?
Expert:  Jason replied 1 year ago.
Thats' why I had asked if it was under warranty or not. The dealer really should be doing it. Did you buy this engine at a dealer or was it cash and carry type of thing? I have to run out for a few minutes, but I should be back in 20 or so.
Customer: replied 1 year ago.
I bought the motor at a dealer in Oregon and had it shipped to Page, Arizona. The previous motor was A Yamaha F90 hp.I have to leave also and won't be back until later tonight. Can we finish this conversation later?
Expert:  Jason replied 1 year ago.
Okay i'm back. There are no time limits here so tomorrow is fine. But as of right now i'm leaning towards either your tach is off. Or the boat is heavy. Is the tach new to the boat or is it the same one that was in there on the 90?
Customer: replied 1 year ago.
It is the same one that was on there with the 90
Expert:  Jason replied 1 year ago.
Is it a Yamaha tach or an other brand?
Customer: replied 1 year ago.
It is the equipment original to the boat. I don't know what brand it actually is
Expert:  Jason replied 1 year ago.
Check the pole setting on the back of the tach. The 150 requires a 12 pole setting. There should be some kind of selector switch or adjusting pot for it.
Customer: replied 1 year ago.
So the back of the tach should have a selector and 12 pin should be an option to switch it to? Does it require any tooling to make the change? Since I am not able to physically be on the boat, I will be able to do that in 2 weeks(I live in California); do I bring another prop with a different pitch?
Expert:  Jason replied 1 year ago.
Just a screwdriver to change the pole, and maybe a couple of small sockets to pop the tach out. And to be honest no I would not buy another another prop until the RPMS/tach setting are confirmed. If you need to do that in 2 weeks that is fine, there are no time limits here. Please just keep in mind the website has already charged you, but they will not credit me unless a rating is done. So if you forget, they still bill you, but they just don't pay me.
Customer: replied 1 year ago.
Is there anyway you can call me right now?(###) ###-####
Expert:  Jason replied 1 year ago.
Phone calls are an extra service provided at an extra fee. I will send you the information over on that. If you accept the offer I can give you a buzz in the next couple of minutes.
Customer: replied 1 year ago.
Okay let's just stay here. If the tach settings are Correct and on 12 pole settings, then what is the next step? Is it look for a differently pitched prop?
Expert:  Jason replied 1 year ago.
No it would be verifying the RPMS with another tachometer. Here is the thing with prop pitch. For every 1 you go down you gain 200 rpms, but you might not get any speed. Full throttle rpms on this engine is 5000 to 6000. As long as you are in that window you are technically okay. So RPMS do need to come up by at least 100 just to be in the operating window (assuming the RPMS prove correct) If you have a 15 pitch now, dropping down to a 10 pitch would bring the rpms up to 5900, but you may or may not gain any actual speed. So verifying RPMS comes first before doing anything else.
Expert:  Jason replied 1 year ago.
Hello, I noticed no rating has been done yet so I'm just checking in to see if you had any further questions on the issue. If there was anything else feel free to ask.
Thanks,
Jason

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