Results 1 to 14 of 14

Thread: Catalac 8m Outboard 9.9hp Yamaha High thrust

  1. #1
    Join Date
    Jul 2018
    Location
    Montego Bay , Jamaica
    Posts
    5

    Default Catalac 8m Outboard 9.9hp Yamaha High thrust

    Hi,

    considering replacing utboard on Good Vibes, a 8m Catalac, have seen some 8m use a 9.9 Yamaha high thrust outboard. Do you think is a good Option?

  2. #2
    Join Date
    Jul 2009
    Location
    Gosport
    Posts
    345

    Default Re: Catalac 8m Outboard 9.9hp Yamaha High thrust

    The Yamaha 9.9 high thrust is a very good engine and designed for powering yachts, so the perfect choice
    which is why you see so many of them on cats.

  3. #3
    Join Date
    Jul 2018
    Location
    Montego Bay , Jamaica
    Posts
    5

    Default Re: Catalac 8m Outboard 9.9hp Yamaha High thrust

    Quote Originally Posted by SteveH View Post
    The Yamaha 9.9 high thrust is a very good engine and designed for powering yachts, so the perfect choice
    which is why you see so many of them on cats.

    Thx SteveH,

    Anybody can tell me about their own experience with this of engine on a Catalac 8M?

  4. #4
    Join Date
    Feb 2009
    Location
    Belgium
    Posts
    386

    Default Re: Catalac 8m Outboard 9.9hp Yamaha High thrust

    No clue about the Yamaha high-thrust outboards, they seem tot be an excellent choice but indeed best check as my understanding is an 'extra-long' or 'ultra-long' leg outboard is preferred on the 8M...
    1979 Catalac 8M - 8-84 - Samimiy
    http://facebook.com/groups/catalac/

  5. #5
    Join Date
    Jul 2018
    Location
    Montego Bay , Jamaica
    Posts
    5

    Default Re: Catalac 8m Outboard 9.9hp Yamaha High thrust

    Quote Originally Posted by djeeke View Post
    No clue about the Yamaha high-thrust outboards, they seem tot be an excellent choice but indeed best check as my understanding is an 'extra-long' or 'ultra-long' leg outboard is preferred on the 8M...

    Thx for the info! Would love to hear from some owners with 9.9 Yamaha Hight thrust as a main engine.

  6. #6

    Default Re: Catalac 8m Outboard 9.9hp Yamaha High thrust

    The downside of the 9.9 Yamaha is that it is not an ultra or extra long shaft although I am told it is a good engine by those who have had it on an 8M, apart from lifting out. I think that 9.9 is underpowered for an 8m even with the higher ratio gearbox and 4 blade prop. I think the Tohatsu 9.9 with ultra long prop is better. I have a 20hp Tohatsu with a 4 blade prop and I would still like some more power. I had a30hp 2 stroke that seemed just right but I changed it for something less thirsty.

  7. #7

    Default Re: Catalac 8m Outboard 9.9hp Yamaha High thrust

    I understand that your question is in reference to a Catalac 8M, but just for information, I had a Yamaha 9.9 High Thrust outboard installed on my Catalac 9m for several years. For its size, I was impressed with the 9.9's power, but I always felt under powered in many situations. It pushed my Catalac 9M well in calm seas, but as soon as I was heading into a strong current or heavy seas, my top speed would drop down to about 1.5 knots. After getting tired of having a row of powerboats lined up behind me trying to get through a tight channel with a very strong current, I decided to replace it with a Mercury 25HP Big Foot outboard. At the time, the Merc 25 HP 4 Stroke outboard was one of the few 4 stroke outboards that would fit into my outboard well on my Catalac 9M without having to do alot of major modifications to the stern platform on my boat in order to be able to tilt up the outboard. One of the problems with the Mercury 25 HP Big Foot (at least back in 2003) was that it was not available with an extra long leg. I was able to buy a leg extension kit from a 3rd party manufacturer that ended up working well. I've been using the extension for around 15 years with no problems. The Big Foot model also comes with gear case thats more suited for pushing a heavy boat slowly. I ended up buying the largest diameter and lower pitch propeller that I could find at the time for that outboard. With the 25 HP Big Foot, I've never felt like I was under powered. I don't think that I've ever had to run it at open throttle since I reach the boats max hull speed before I opened the throttle all the way.

  8. #8

    Default Re: Catalac 8m Outboard 9.9hp Yamaha High thrust

    Quote Originally Posted by proffittjj View Post
    I understand that your question is in reference to a Catalac 8M, but just for information, I had a Yamaha 9.9 High Thrust outboard installed on my Catalac 9m for several years. For its size, I was impressed with the 9.9's power, but I always felt under powered in many situations. It pushed my Catalac 9M well in calm seas, but as soon as I was heading into a strong current or heavy seas, my top speed would drop down to about 1.5 knots. After getting tired of having a row of powerboats lined up behind me trying to get through a tight channel with a very strong current, I decided to replace it with a Mercury 25HP Big Foot outboard. At the time, the Merc 25 HP 4 Stroke outboard was one of the few 4 stroke outboards that would fit into my outboard well on my Catalac 9M without having to do alot of major modifications to the stern platform on my boat in order to be able to tilt up the outboard. One of the problems with the Mercury 25 HP Big Foot (at least back in 2003) was that it was not available with an extra long leg. I was able to buy a leg extension kit from a 3rd party manufacturer that ended up working well. I've been using the extension for around 15 years with no problems. The Big Foot model also comes with gear case thats more suited for pushing a heavy boat slowly. I ended up buying the largest diameter and lower pitch propeller that I could find at the time for that outboard. With the 25 HP Big Foot, I've never felt like I was under powered. I don't think that I've ever had to run it at open throttle since I reach the boats max hull speed before I opened the throttle all the way.
    That is interesting as I looked into a Bigfoot engine 7 years ago when I re-engined from 30hp 2T to a 20hp 4T. Then I thought the better gear ratio on the Bigfoot and ability to swing a bigger prop was exactly what I wanted but the standard long shaft only option deterred me from the Bigfoot. I have been looking at engines again perhaps a 30hp. I am interested in the 3rd party supplier of the gear case extension and longer drive and gear change shafts-do you have the details?

  9. #9
    Join Date
    Jul 2018
    Location
    Montego Bay , Jamaica
    Posts
    5

    Default Re: Catalac 8m Outboard 9.9hp Yamaha High thrust

    Quote Originally Posted by proffittjj View Post
    I understand that your question is in reference to a Catalac 8M, but just for information, I had a Yamaha 9.9 High Thrust outboard installed on my Catalac 9m for several years. For its size, I was impressed with the 9.9's power, but I always felt under powered in many situations. It pushed my Catalac 9M well in calm seas, but as soon as I was heading into a strong current or heavy seas, my top speed would drop down to about 1.5 knots. After getting tired of having a row of powerboats lined up behind me trying to get through a tight channel with a very strong current, I decided to replace it with a Mercury 25HP Big Foot outboard. At the time, the Merc 25 HP 4 Stroke outboard was one of the few 4 stroke outboards that would fit into my outboard well on my Catalac 9M without having to do alot of major modifications to the stern platform on my boat in order to be able to tilt up the outboard. One of the problems with the Mercury 25 HP Big Foot (at least back in 2003) was that it was not available with an extra long leg. I was able to buy a leg extension kit from a 3rd party manufacturer that ended up working well. I've been using the extension for around 15 years with no problems. The Big Foot model also comes with gear case thats more suited for pushing a heavy boat slowly. I ended up buying the largest diameter and lower pitch propeller that I could find at the time for that outboard. With the 25 HP Big Foot, I've never felt like I was under powered. I don't think that I've ever had to run it at open throttle since I reach the boats max hull speed before I opened the throttle all the way.
    thx a lot for the information, do you remember what speeds where you achieving in calm moderates seas?

  10. #10

    Default Re: Catalac 8m Outboard 9.9hp Yamaha High thrust

    Its been a long time , but in calm waters, i think the 9.9 could push my 9m between 6-6.5 knots. It was a good outboard, just too bad it couldn't generate enough thrust up against strong winds and currents. I never experimented with the propeller's pitch, but possibly that could have helped a little . The 9.9 was also very fuel efficient. i believe it only used 0.5 gallons per hour at full throttle.

  11. #11
    Join Date
    Jul 2018
    Location
    Montego Bay , Jamaica
    Posts
    5

    Default Re: Catalac 8m Outboard 9.9hp Yamaha High thrust

    Quote Originally Posted by proffittjj View Post
    Its been a long time , but in calm waters, i think the 9.9 could push my 9m between 6-6.5 knots. It was a good outboard, just too bad it couldn't generate enough thrust up against strong winds and currents. I never experimented with the propeller's pitch, but possibly that could have helped a little . The 9.9 was also very fuel efficient. i believe it only used 0.5 gallons per hour at full throttle.
    Thank you! Impressed with 0.5 gallons an hour it’s awsome!

  12. #12

    Default Re: Catalac 8m Outboard 9.9hp Yamaha High thrust

    I believe that I got the extension kit at Bay Manufacturing , http://www.baymfg.com/. The kit that i bought was 228

  13. #13

    Default Re: Catalac 8m Outboard 9.9hp Yamaha High thrust

    Quote Originally Posted by proffittjj View Post
    I believe that I got the extension kit at Bay Manufacturing , http://www.baymfg.com/. The kit that i bought was 228
    Thank you for that link - it opens up all sorts of options for extending outboard legs at not a huge price. I like the concept of 5" stub extenions for the water tube, gear change and drive shaft. My only concern about the spec is that the drive shaft is stainless and I am not sure that is the best material for this, but maybe it is?
    Looked at Bay Engineering and a good range of extension options and engine makes.

  14. #14

    Default Re: Catalac 8m Outboard 9.9hp Yamaha High thrust

    Quote Originally Posted by GoodVibes View Post
    Thank you! Impressed with 0.5 gallons an hour itís awsome!
    I get an overall average of 0.7 imperial gallons per hour with my Tohatsu 20hp and normally cruise at 5kn, perhaps 4 if it is rough. Max is about 6.9kn at 6000rpm with a 4 blade hi-thrust prop.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •