How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask K. Kergan Your Own Question

K. Kergan
K. Kergan, Marine Mechanic
Category: Boat
Satisfied Customers: 994
Experience:  24 yrs exp. Inboard/Outboard mechanic Mercury/ Mercruiser, Volvo Penta and OMC, Johnson/Evin.
13730749
Type Your Boat Question Here...
K. Kergan is online now
A new question is answered every 9 seconds

I have a 4JH3TE Yanmar Engine and fitted gearbox KBW 21 clutch

Customer Question

I have a 4JH3TE Yanmar Engine and fitted gearbox KBW 21 clutch in a 34Ft cruiser I purchased this boat as is. I am not too sure this is the gearbox that should be fitted
I sure would like your advice on this gearbox and suggestions you may have to a replacement that would fit the engine and where would I find the proper box

Kind Regards.
Frank Finegan.
Submitted: 2 years ago.
Category: Boat
Expert:  Michelle-Mod replied 2 years ago.


Hi, I’m a moderator for this topic and I wonder whether you’re still waiting for an answer. If you are, please let me know and I will do my best to find a Professional to assist you right away. If not, feel free to let me know and I will cancel this question for you. Thank you!


Customer: replied 2 years ago.
I am not sure what information you are looking for, I did not receive any answer to my query.
Regards


Expert:  Walt-mod replied 2 years ago.
Thank you for your patience, your business is very important to us, we are waiting on the Professional with the right expertise to come online. Feel free to let us know if you would like us to continue searching for an Professional or if you would like us to close your question. Thank you for your understanding!
Customer: replied 2 years ago.
Yes I would like as much information as possible to my question,thanks
Regards.
Frank
Expert:  K. Kergan replied 2 years ago.

Hi, my name is Kerry

Yanmar offers three different transmissions with this engine, the KM4A is an angle drive with a cone clutch and the KBW20 and KBW21 are both straight drives with a multidisc clutch pack. The KBW21 is the more durable of the two.

Why do you think it's the wrong transmission for your application?

Customer: replied 2 years ago.
Hi.Kerry.
Thanks for getting back to me,my problem is i do not know the difference between the different boxes,The KBW21 box seems to be a crash box to explain the shaft needs to be stopped rotating before changing gear I think.Most other boats you can go from forward to reverse very quickly.
I am not sure I can do this with the KBW21,If not which box would be suitable.I have found out this engine and box were bought for a barge and the deal fell through, they were fitted to the cruiser then.The boat works fine other than trying to get it in to and out of gear.
Regards.
Frank Finegan.
Expert:  K. Kergan replied 2 years ago.

The KBW20 and KBW21 are identical except that the KBW21 has it's gears specially treated to be harder and more durable. The KBW21 is used on more powerful engines than the KBW20. Aside from the temper on the gears these two transmissions are virtually identical and are available in the same gear ratios.

The KM4A is a transmission with a cone clutch which may be more to your liking but it would mean that the engine orientation would need to change because of the angle on the output flange.

I seems to me that the transmission you have now should be able to shift fwd/rev/fwd/rev just like any other marine gear.

K. Kergan, Marine Mechanic
Category: Boat
Satisfied Customers: 994
Experience: 24 yrs exp. Inboard/Outboard mechanic Mercury/ Mercruiser, Volvo Penta and OMC, Johnson/Evin.
K. Kergan and 2 other Boat Specialists are ready to help you
Customer: replied 2 years ago.
HI Kerry.
Thanks for your reply It gives me peace of mind now.

JustAnswer in the News:

 
 
 
Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.
 
 
 

What Customers are Saying:

 
 
 
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C. Freshfield, Liverpool, UK
< Last | Next >
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C. Freshfield, Liverpool, UK
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex Los Angeles, CA
  • Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult. GP Hesperia, CA
  • I couldn't be more satisfied! This is the site I will always come to when I need a second opinion. Justin Kernersville, NC
  • Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around. Esther Woodstock, NY
  • Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know. Robin Elkton, Maryland
  • He answered my question promptly and gave me accurate, detailed information. If all of your experts are half as good, you have a great thing going here. Diane Dallas, TX
 
 
 

Meet The Experts:

 
 
 
  • Dominick

    Marine Mechanic

    Satisfied Customers:

    1009
    25 Years Experience as Mechanic, 20 Yrs Boat Yard Owner/Mechanic, Factory Certified
< Last | Next >
  • http://ww2.justanswer.com/uploads/dominickb/2008-12-14_204035_dominick.jpg Dominick's Avatar

    Dominick

    Marine Mechanic

    Satisfied Customers:

    1009
    25 Years Experience as Mechanic, 20 Yrs Boat Yard Owner/Mechanic, Factory Certified
  • http://ww2.justanswer.com/uploads/TE/TedG/2012-6-15_14759_avaLarge.64x64.jpg Ted G.'s Avatar

    Ted G.

    Rigger, Diagnostician

    Satisfied Customers:

    557
    40 years boating, Safe boating instruct., Offshore Race promoter, Failure Analysis, Expert Witness
  • http://ww2.justanswer.com/uploads/whitesmarine/2009-11-07_025719_07011.JPG John White's Avatar

    John White

    Marine Mechanic

    Satisfied Customers:

    306
    11 years experience working on outboards, inboards, sterndrives & pwcs
  • http://ww2.justanswer.com/uploads/OL/oldnewenglandmarine/2012-9-8_15014_icon.64x64.jpg Jason's Avatar

    Jason

    Marine Mechanic

    Satisfied Customers:

    7718
    Degree in Marine Technology. Gas and diesel marine mechanic.
  • http://ww2.justanswer.com/uploads/JA/jacksparrow1956/2011-1-16_191846_009.64x64.JPG Tan's Avatar

    Tan

    MerCruiser Certified Technician

    Satisfied Customers:

    7330
    39 yrs. experience with complete engine repairs both inboard/outboard and MerCruiser Certified Technician.
  • http://ww2.justanswer.com/uploads/JE/JeffGr/2012-6-15_14217_20001003AA1.64x64.JPG Jeff G.'s Avatar

    Jeff G.

    Marine Mechanic

    Satisfied Customers:

    4172
    39 years experience, Certified Master Technician, All Major Outboards, Sterndrives, Hi-Performance
  • http://ww2.justanswer.com/uploads/dkreines/2008-3-22_155128_daveja.jpg Captain Dave's Avatar

    Captain Dave

    Marine Mechanic

    Satisfied Customers:

    2672
    USCG Licensed Captain, 20+ Years Boating, Fishing, Maintenance and Repair Experience
 
 
 
Chat Now With A Marine Mechanic
K. Kergan
K. Kergan
Inboard/Outboard Mechanic
994 Satisfied Customers
24 yrs exp. Inboard/Outboard mechanic Mercury/ Mercruiser, Volvo Penta and OMC, Johnson/Evin.