View Full Version : Honda 90 ready to blow up Help pleae

06-24-2009, 06:35 AM
"Hi there, new to this forum so any help would be most appreciated as im in a bit of a fix here.

Was about about 6 miles out in my boat last night and driving about 3700rpm when the engine (honda 90 1999 model i think) suddenly lost power and changed tone into sounding basically like a bag of crap. It went loud noisey (not clunky just noisey)and i switched it straight off and gathered my thoughts then started it and revved up (to it to about 2500rpm maybe) for about 10-20 secs to try decide what the noise was. I then switched it back off and lifted the cover and checked the dipstick only to find that the oil was pretty frothy/going whitish which made me panic a little as ive just spent more or less all my savings on the boat/engine and know when oil goes like this its not good.

Any ideas as to whats wrong and what parts i could potentially need to repair it? Im capable of fixing minor problems but havent got a clue about boat engines.

I know im new here so please me for being a bit ignorant and wading in with some questions but im really in need of some help from people who know about these things. Any more details needed please ask me and i'll fill you in. cheershttp://www.marineengine.com/discus/clipart/thumbs_up.gif"

06-27-2009, 05:06 AM

06-27-2009, 09:28 AM
"First of all this a bit problematic, you need to know for sure that you have water in the oil, it is better you take the engine to understand someone not spoil other parts"

06-27-2009, 12:09 PM
"Alex is correct; his translator makes his English a little difficult to understand.

Marine engine oil will mix with a little water and turn cream color, first on your list would be an oil change.

You will need to pull all your spark plugs, keep track of cylinders and look for one or more that looks 'too clean' as water in combustion chamber steam cleans spark plugs.

Next should be a compression test, (or a 'leakage test' if you bring to marine technician) and look for one or more 'low' cylinders.

Likely source of water in combustion chamber would be a failed head gasket or possibly even a crack or hole in head or cylinder wall.

Replacement of head gasket would be easy enough, if you get the Honda Shop Manual for your engine and take the head to a Marine/Automotive Machine Shop for check and re-surface.

http://www.boats.net/parts/search/Honda/Outboard%20Engine/parts.html ("]http://www.lings.com/lingscentralapp_core.0.LassoApp?pg=nav&catview=369 d56fc0f1a bfc3&sectnum=3dce8e6541f60623&catnum=431cfcce605f2 c70&-session=Lings:4C01A0960f4 f5287B8txmG180D34&-session=Lings:4C01A0960f4f5287B8txmG180D34[/url]

The link above is to a UK source of Honda Shop Manuals for 'pdf' download at a cost of 10.00.

Check with your PayPal or Credit Card for currency conversion fees.

This is a good site for online or telephone parts:


They also have 'zoomable' (and printable) blowup diagrams from Honda Parts catalogs."