1999 Honda 90hp major problems. Please advise :)

[Mr Mojo Risin]

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. cheers

[gonzo]

What you describe looks like water in the oil. There can be many causes, from a bad gasket to a crack in the block or the head. At this point, taking the head off is the first step to check it out. If you work in automotive engines will find the mechanical parts similar.

[Mr Mojo Risin]

hi there thanks for replying

i'll order up a gasket kit and have a looksy under the head and check for any obvious damage/scores. could the change in noise be caused by something as simple as a head gasket? its hard to describe the noise it made but sudden power loss and instead of the 'brrrrrrrrrrrrrrr' noise it kindof changed to a 'loud buuuuuuuuuuh' noise. i hope it something simple as ive not left much cash spare for repairs (sods law).

any other feedback would be great -cheers-

Cyl. head gasket if you´re happy. But thats a guesstimation only. So, I would´nt buy anything before the head is removed.

Regards
Richard

[Manie B]

Mojo be very carefull, the Honda is a complicated motor with a complicated head (V-Tec et al)

it should be opened by an experienced technician

that the oil was pretty frothy/going whitish

almost 100% sure that is water in the oil - BEEEEEG PROBLEM not to be underestimated

sorry pal outch

[pistnbroke]

no dont take the head off that destroys the evidence ...bring each cylinder up to tdc and apply compressed air to each cylinder in turn via a plug adaptor ....listen and look where it leaks out and which cylinder .......not as good but a compression test may tell you which cylinder is the suspect one ....

If it was head gasket you would be looking at water getting into the oil return gallery to the sump ( oil returned after lubricating the valve gear ) ......

If you spent money on a repair at a shop that has gone bad you may have a claim for them to fix it ....

[Rangerspeedboat]

Always start with the cheapest part that could be the a problem causer.

Water in oil....not a good thing.

[Mr Mojo Risin]

again, thanks for the replies

i can get a compression tester from my local garage if i need one. should i give this a shot? i wasnt sure whether to restart it incase it made the problem even worse? my local mechanic said i should use the tester and if all the compression readings are the same its not the cylinder head (or was it the other way round? lol i was lightly tipsy when he was explaining last night in the pub!)

would i be safer just sticking to pistonbrokes advice and trying to track down an airline adaptor and testing for leaks that way?

i understand this job really should be repaired by a pro but thats really as last resort for me as ive just blew all my savings on the bloody boat so im hoping to wing it through this on my limited funds and knowledge (and you guys advice!). I do have friends who are motor mechanics but none have much experience in outboard motors apart from the odd carb clean or that kiondof thing.. The head is going to be removed to diagnose the problem so im going to have to buy a gasket kit either way?

No, do´nt buy anything! As mentioned above it might be even more than a leaking gasket. If the block is cracked for what do you need a resealed head?
Do the compression test first. We´ll see.........

Regards
Richard

[gonzo]

A compression test will not give you an indication of a bad gasket or crack, unless they are in the combustion chamber. Very often the leak is at the other areas of the gasket.

[Manie B]

Interesting topic

firstly ALL THE ABOVE IS CORRECT thanks guys it also gets my old brain going again

on this type of motor the possibility of a cracked block is very low
a warped head and leaking head gasket high possibility
a welsh plug of sorts leaking, if it exists in this motor also high

leaking head gaskets could occur easily on a outboard after over heating which was not notice (or denied) by the previous owner

The technology we applied to our newest outboard engine is the very same that powers one of the most popular cars in the world, the Honda Fit. A 4-cylinder, 1496cc(91.4ci) engine, weighing in at only 163kg (359 lbs.). It's the lightest in its class.

http://www.honda-marine.com/modeldet...lGroup=bf90efi

these motors were also used by one of my favourite reads "C-Dory"

http://www.geocities.com/bill_fiero/

somewhere along the line they were told that it would be cheaper to buy new motors rather than to repair, because they obviously got their usasge out of it.

i found this manual - BE WARNED - 1139 PAGES

http://www.psytronix.org/honda/manua...viceManual.pdf

THE BLOOMIN MANUAL IS PASSWORD PROTECTED
so you cant print any pages

The pages that spell danger are 96 to 106 which shows you the head assembly - it is complicated to say the least

once again DO NOT attempt this if you have not been trained
sorry for my french - but you are gonna fu3k it up - AND it gonna hurt BAD

Originally Posted by gonzo

A compression test will not give you an indication of a bad gasket or crack, unless they are in the combustion chamber. Very often the leak is at the other areas of the gasket.

Gonzo if the Head Gasket is gone to a point that you have water in the oil I doubt that your compression is correct.
And the Head Gasket IS sealing the combustion chamber right?

Regards
Richard

[pistnbroke]

read my lips ...compressed air into the plug holes and see/listen where it comes out ..shut off air and see how fast the pressure falls on each cylinder ...sounds like a leak between the water feed to the head and the return for the valve gear lub oil to the sump ...these are only car engines on end ....

[Manie B]

i tried to play with the PDF but my "hacking" skill's are no good

so i just took pics of the manual (btw the manual is very interesting)

enjoy