Click for Honda Manuals, Parts and Model Guides!
Results 1 to 3 of 3
  1. #1

    Exclamation 2001 Honda 90 hp water in crankcase?

    I have a 2001 Honda 90 four stroke outboard. My son overheated it. I had it rebuilt by a local repair shop. Initially there was no water in the crankcase mixed with the oil. After rebuilding the motor they ran it on a set of earmuffs to check it in the shop. Runs great, no problems on the muffs. When you put the boat in the water and run it, The crankcase immediately fills to the top with water. Somehow the exhaust back pressure is causing the crankcase to fill rapidly with water. The shop has done all it can to this and it is evident that they were not very experienced at this model of outboard. I am trying to get some suggestions as to the cause of the leak. Is it the block, the head or did they not put it back together correctly. I cannot find a knowledgeable mechanic for this model in my area. Any help or testing techniques are much appreciated.

  2. #2
    Join Date
    May 2009
    Virginia Beach, Va., USA

    Default Re: 2001 Honda 90 water in crankcase?

    Well I'm certainly no expert, but I did own a 2000 Honda 90 and I pulled the head and changed a head gasket. I had the head checked by a marine machine shop and it was slightly warped. They milled it flat and it was still within Honda specs.

    In my case, exhaust gas was blowing into the water jacket causing overheats at high RPM.

    To my untrained mind, they didn't put the head gasket on correctly, or used the old one, or you have a cracked head or block. I think you are going to have to pull the head off again, inspect everything and replace the gasket.

    Have you tried doing a compression test? What does that show?

    If you would like to see what the engine and head look like taken apart, email me and I will send you the pics I took.

    The hardest/longest part of the job for me was adjusting all those valves. Other than that it was pretty straight forward. I used a Honda shop manual.

    Maybe one of the Hondadudes will chime in with words of wisdom. They are the pros!

  3. #3
    Join Date
    Mar 2009
    Cincinnati, OH USA

    Default Re: 2001 Honda 90 water in crankcase?

    I am with Popgun...they may have reused gaskets or did not install them properly.

    Did they rebuild the whole thing? Did they remove the entire engine or just the head?

    If they removed the entire engine and they did not put in new oil pan gasket (below the mount case) or mount case gasket (above the mount case), the oil pan, water and exhaust are all there and a lot can happen with water pressure, backpressure and a bad gasket.

    The water tube grommet should have also been replaced.

    All the above assumes that the rebuild was done correctly and you have a solid powerhead. Good compression and leakdown.

    I hope they gave you some sort of refund if they are not going to fix the problem.

    I have to think, where would I start if this came into our shop this way...

    The first thing - we would tell the customer to go back where they had it repaired.

    The second thing - if they insisted, I would then get their signed blank check...sorry...I could not resist that one.

    Actually, I would drain the oil and try to pressurize the water system with low pressure air and see if I could locate the source of the leak. Since I have not tried that with a 90 HP, I am not even sure it is possible.

    Most likely, I would just start disassembling and inspect gaskets as I go...starting with the two I stated above. Which means, the lower unit, lower housing, oil pan, etc have to come off...then the power head has to be removed.

    I only had to do this a couple of times on other Hondas (similar situations...where someone else had the hands in it) and the answer was obvious...once I found it.

    Good luck!


Similar Threads

  1. Honda 1996 50 hp Water in Crankcase oil
    By flip1234 in forum Honda Outboard Forum
    Replies: 3
    Last Post: 01-04-2010, 05:09 PM
  2. Water or Gas in my crankcase Honda BF35
    By apat03885 in forum Honda Outboard Forum
    Replies: 6
    Last Post: 10-15-2009, 01:09 AM
  3. Water in crankcase of Honda BF100
    By morecoffee in forum Honda Outboard Forum
    Replies: 9
    Last Post: 09-15-2009, 02:57 PM
  4. Honda 50 fuel in crankcase oil
    By pescadito in forum Honda Outboard Archive
    Replies: 13
    Last Post: 05-04-2008, 02:25 PM
  5. 2001 8 hp honda fourstroke water pump problem
    By Roc Stacey in forum Suzuki Outboard Archive
    Replies: 8
    Last Post: 09-13-2006, 04:25 PM

Posting Permissions

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