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Results 1 to 23 of 23
  1. #1

    Default Converting 50hp to 60hp 4 stroke. (also 75hp to 90hp)

    Hi guys, Im new here and found this forum today. I have a question...

    I recently bought a new hull and have put my 2010 EFI F50hp on it. The new hull is rated to 60hp and I really want the extra 10hp. I have been researching this a lot lately but its hard to get definate answers on a couple of things.

    Now I understand you can do a simple mod by removing the air intake restrictor plate on the 50 to make it the same as the 60hp. I also understand that the ECU's in the two engines are similar but different (I dont know what is different). The part numbers are NEARLY the same 6C5-8591A-32-00 ($848.80) and 6C1-8591A-32-00 ($711.80). I understand the ECU in the 50hp has a rev limiter set to approx 6000RPM and the ECU in the 60hp has a rev limiter set to 6200RPM. This alone would suggest a difference in part numbers but is there more to them with the price being different as well??

    I decided to remove the intake restrictor plate and here are the results...

    I started with my 11' prop which used to spin at 5300rpm (48kmh) with the restrictor plate in. It now spins at 5800rpm (53kmh) without the restrictor. I then upsized to a 11 5/8" X 12" SOLAS which used to get 5000rpm (50kmh) WOT (slow off the mark). It now gets 5400rpm (53hmh) without the restrictor but noticably quicker up and out of the hole. The motor is running beautifully as ever after 3 hrs without the restrictor plate.

    BUT...I am worried that I may eventually be doing some damage if the ECU hasnt adjusted and it thinks its still running a 50hp and may be running leaner? So my main question is...will I damage my engine or will the ECU compensate automatically (if it needs to?)? I cant afford to damage my engine but I will modify the ECU if I need to.

    Any help on this would be fantastic. I got a lot of my info online at http://www.refugeforums.com/refuge/s...d.php?t=771608

    Cheers. Chris.

  2. #2
    Join Date
    May 2010
    Location
    Sebastian ,Fl
    Posts
    1,590

    Default Re: Converting 50hp to 60hp 4 stroke. (also 75hp to 90hp)

    Run it at WOT for a few minutes.Then shut it off while its at high RPM and pull the plugs abd see how they are burning.
    Post pics.
    Sometimes the only difference in HP is the modual.Had a Merc 225 and the dif.between the 200 and 250 was the ECU.
    Look up the specs on your motor for bore and stroke and compare to the 60.J
    boats . net worst place to buy parts.
    Get towing insurance.Great investment.
    88 Bayliner with twin 85's

  3. #3

    Default Re: Converting 50hp to 60hp 4 stroke. (also 75hp to 90hp)

    The specs for the 50 and the 60 are the same except two things....the 50 has a restrictor plate in the air intake and the ECU has a slightly different part number but the ECU's are listed as interchangeable.

  4. #4

    Default Re: Converting 50hp to 60hp 4 stroke. (also 75hp to 90hp)

    Bump...

    Anyone else know about this this topic?

  5. #5

    Default Re: Converting 50hp to 60hp 4 stroke. (also 75hp to 90hp)

    Chris:

    I stumbled across your post, while researching the 50 to 60 upgrade and followed the link to the Refuge. I haven’t much else on the topic, still searching. If I find any info I will post it here.

    Is yours still running fine?

  6. #6

    Default Re: Converting 50hp to 60hp 4 stroke. (also 75hp to 90hp)

    Still running like a dream Gary. Around 10 hrs use now.

    I emailed a technical advice guy in the US about it (sells performance parts for outboards) and his response was..

    "One thing is for sure, you will not damage either the ECU or any other part. Maximum you will detect flat spot when throttling or throttle response will spoil if the air is too much."

    Thats as far as Ive gotten with info since last post, but someone has told me the ECU can be re-programmed with the 60HP data. Can't confirm this and dont really think it will make much difference.

    The restrictor is staying out of my engine.

  7. #7

    Default Re: Converting 50hp to 60hp 4 stroke. (also 75hp to 90hp)

    Sounds like your talking about the newer yamaha outboards. i have an 86' carb'd yamaha 70ETLJ. I was wondering if anyone has ever swapped the jets and needle out with jets and needle from the 90ELTJ. I have done some research, the part numbers are very very close to the same. it is simply changing the needle and going from a #78 to #80 Jet and from a 150 Main to 165 Main Jet. I thought of this because my buddy has an old carb'd mariner 115 and his mechanic swapped in the mariner 150 jets and he now has a 150 with 115 decals. There is quite a difference in power all around. Do you think the 90 jets would make a noticeable increase in power? I want to guess for some reason the top end might gain a max of another 5-6MPH, but the bottom end would benefit most when coming out of the hole. What are your thoughts? Let me know any of your thoughts

  8. #8
    Join Date
    Mar 2012
    Location
    Lithuania
    Posts
    5

    Default Re: Converting 50hp to 60hp 4 stroke. (also 75hp to 90hp)

    Quote Originally Posted by Chris79 View Post
    Still running like a dream Gary. Around 10 hrs use now.

    I emailed a technical advice guy in the US about it (sells performance parts for outboards) and his response was..

    "One thing is for sure, you will not damage either the ECU or any other part. Maximum you will detect flat spot when throttling or throttle response will spoil if the air is too much."

    Thats as far as Ive gotten with info since last post, but someone has told me the ECU can be re-programmed with the 60HP data. Can't confirm this and dont really think it will make much difference.

    The restrictor is staying out of my engine.
    No problem. I can help you and reprogram the ECU from YAMAHA F50 to F60, F80 to F100 is a small fee. We also have an option to disable the function of IMMO.

  9. #9

    Default Re: Converting 50hp to 60hp 4 stroke. (also 75hp to 90hp)

    Quote Originally Posted by audis View Post
    No problem. I can help you and reprogram the ECU from YAMAHA F50 to F60, F80 to F100 is a small fee. We also have an option to disable the function of IMMO.
    Im interested please let me know how we can do this? What is the IMMO again?

  10. #10
    Join Date
    Mar 2012
    Location
    Lithuania
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    5

    Default Re: Converting 50hp to 60hp 4 stroke. (also 75hp to 90hp)

    See PM

  11. #11

    Default Re: Converting 50hp to 60hp 4 stroke. (also 75hp to 90hp)

    But remember that your motor, or any motor for that matter, has only so many hphours. If you get more hp out of it then it's life will get shorter.

  12. #12
    Join Date
    Mar 2012
    Location
    Lithuania
    Posts
    5

    Default Re: Converting 50hp to 60hp 4 stroke. (also 75hp to 90hp)

    Quote Originally Posted by villtur View Post
    But remember that your motor, or any motor for that matter, has only so many hphours. If you get more hp out of it then it's life will get shorter.
    Yes. that is part of the truth even if it were tuning programming, but in this case I just rewrite the program inside the ECU from original F60 to F50. This is the same as buy a new ECU.

    It can also be transcribed from F50 to F60, but whether it is someone like it
    Last edited by audis; 03-29-2012 at 04:29 PM.

  13. #13

    Default Re: Converting 50hp to 60hp 4 stroke. (also 75hp to 90hp)

    "This is the same as buy a new ECU." which also will shorten the motor's life. In short; there is no substitute for cubic inches. More hp from same volume gives shorter life.

  14. #14
    Join Date
    Mar 2012
    Location
    Lithuania
    Posts
    5

    Default Re: Converting 50hp to 60hp 4 stroke. (also 75hp to 90hp)

    Yes. But only if the motor is more than 50% of the time work the maximum speed. But reality shows that the engine operates most of the time up to 3000 rpm.
    Also, not to manufacture Yamaha's F60 model if it would be unstable

  15. #15

    Default Re: Converting 50hp to 60hp 4 stroke. (also 75hp to 90hp)

    Of course you are correct. But if you don't plan to squeeze every last drop of horsepower out of the motor what's the use of buying it for many money?
    But to each his own. Who am I to mind how other people use their money?
    Have fun.

  16. #16
    Join Date
    Mar 2012
    Location
    Lithuania
    Posts
    5

    Default Re: Converting 50hp to 60hp 4 stroke. (also 75hp to 90hp)

    Yes you are absolutely right. But in life come in the situation where people receive a gift engine or other means. And the power of them is low, and sell the existing engine is quite difficult, and buy a new need to add a significant amount of money. And therefore remains one of the options to try to increase their own power.
    Sorry for my English

  17. #17

    Default Re: Converting 50hp to 60hp 4 stroke. (also 75hp to 90hp)

    Hi All, thanks for the useful information within this thread, I have been looking at doing similar to my 2007 F80BETL as looking at the bore/stroke rates all seems identical between it and the F100, the squish area in the head may be a slightly different design but i doubt it as most manufacturers prefer to use common parts where they can.

    For those worried about a change of ECU this is not really an issue, there may be some slight fuel and timing map differences however all modern EFI ECU's are designed to notice and adapt to changed conditions, they have an AFM, TPS and an O2 sensor to give feedback to the ECU to control spark retardation and fuel map positions. The ECU will adapt to the higher airflow by pushing the fuel load higher in the map table to suit but still try to maintain AFR at stoic. The only exception to this is at WOT (wide open throttle) at this point the fuel map is at peak, if there is a difference between the two ECU's then this is where it will have the most effect by running the engine lean, for me this is no issue as I almost never run my engine at WOT mostly its about 1000rpm below the limiter and for me thats only 4500rpm at around 21Kn

    Anyway some useful information for reference as I have just removed the restrictor in my engine....

    The restrictor in the F80 reduces the intake port diameter to 24mm. Without the restrictor the diameter is 41mm, thats a significant difference. The restrictor is actually really well designed with good fluting on each side. What this means is that on removal there may be some change in the airflow characteristics toward the intake port. When looking at the length and design of the runners they seem to be a tuned length. fortunately they are quite long runners so most turbulence will be settled before they hit the intake and IMHO any flow distortion and fuel droplet issue at the injector will be negligable compared to HP gain.

    Just a quick one on flow rate for those technically minded, these are not hugely accurate as there are too many variables but...
    assuming 3cm length and 0.1bar pressure drop

    40mm flows 678cc
    24mm flows 238cc

    I wont get the boat on the water for a couple of weeks but once I do ill let you know how much difference it will make. If someone can host them I have plenty of photos of the removal and dimensions that could be posted up.

  18. #18

    Default Re: Converting 50hp to 60hp 4 stroke. (also 75hp to 90hp)

    Thanks for the great info ira11y. I'm very interested to hear how your engines goes without the restrictor.

    I have recently upgraded to the same engine as you. My previous 50hp ran like a dream for over 250hrs after I removed the restrictor with noticeable extra power and speed. I ran it at WOT for long periods of time without any dramas as well.

    I dont really need the extra power with the new 80hp but I am very keen to hear how you go. I read about a certain dealer removing the intake air restrictors on their 80hp engines prior to them going out the showroom so I dont think there can be too many issues to worry about.

    Cheers and keep us posted with your results please.

  19. #19

    Default Re: Converting 50hp to 60hp 4 stroke. (also 75hp to 90hp)

    Ok so I had the boat in the water a few weeks ago and it all ran fine, the most noticeable difference is in the rev range and I really diddnt push it too hard, however where the engine used to stop breathing at 5500rpm it will now easily rev to 5800rpm and beyond, I held it back at 5800rpm until I get a real feel for the changes and feel confident to push it beyond that. The engine should be able to rev to about 6500rpm now in theory at least.

    Without throwing the throttle control to WOT but using about 3/4 throttle from standing start there is a noticeable difference in acceleration. I diddnt have the GPS fine logging on this time out but I can tell from the speed/rpm ratio there is an overall improvement, on average I have gained around about a 1Kn speed improvement vs rpm accross the top of the rev range. For example previously at about 4500rpm I would get about 21Kn, now its closer to 23Kn as my cruising speed. This is consistent accross the whole rev range. The engine is obviously delivering slightly more power per stroke to achieve this through a better AFR.

    With regard to top end previously I would get to about 29-30Kn at 5500rpm, 31Kn on a good day into a head wind (air lifting the boat out of the water assists in drag reduction), now that I can rev higher in the range I got to 33Kn @ 5800rpm and theres still a little more in the legs from the engine after that but for what I do I am not likely to need those sort of speeds.

    Fuel economy has changed, where I used to get around 8L/Hr its now about 9.5L/Hr but it was pretty flat when we went out and so we were crusing a bit faster than we would normally out the front and you could probhably take off about 0.5L/hr to take this in to account based on my previous logs.

    Ive put photos up of the restrictor here....

    http://s323.photobucket.com/albums/nn455/ira11y/

  20. #20

    Default Re: Converting 50hp to 60hp 4 stroke. (also 75hp to 90hp)

    Hi, I am new here and been looking to up the output of my f50. I have found an outfit in CA, Simon motor sport, that can re-program the ecu but it cost as much as buying a new one. Was wondering if anyone has come any others that can do the work and are more reasonable.

  21. #21

    Default Re: Converting 50hp to 60hp 4 stroke. (also 75hp to 90hp)

    Would this work on a 2013 f50 ?
    Are there any differences or major changes to the motor this year ?
    When did they introduce multipiont EFI ?
    Any info would be great !

    Thanks

  22. #22

    Default Re: Converting 50hp to 60hp 4 stroke. (also 75hp to 90hp)

    Quote Originally Posted by audis View Post
    No problem. I can help you and reprogram the ECU from YAMAHA F50 to F60, F80 to F100 is a small fee. We also have an option to disable the function of IMMO.
    .

    I am interested in your offer of increasing HP of Yamaha 4 cycle outboard.

    I own a 2002 50 HP Yamaha 4 cycle outboard that i purchased recently. The outboard had been in storage and is new, still in the crate. I am interested in getting 60 HP out of it. I am curious what parts increase the HP, and if the ECU is programmed differently. I would rather not go to the expense of changing carburetors, however. I am willing to pay a reasonable fee for information, and will prepay. My email address is DaveLadely@aol.com, phone 206-354-0857. cheers, Dave Ladely

  23. #23

    Default Re: Converting 50hp to 60hp 4 stroke. (also 75hp to 90hp)

    Thanks ira11y Sounds like its working well. Ive seen the same results. My engine maxs out the rev limiter at 6200. One thing I have noticed is the fuel consumption and economy have changed as well. It's using more fuel which shows the fuel mapping/sensors are capable of noticing the extra air and compensating by adjusting the fuel flow according and not running lean.

    DaveLadely is 2002 model carby? No ECU? You can still remove the air intake restrictor to pick ups some extra HP.

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