35hp cappucino plugs

[Phatslax]

Hi , took my 35hp '83 Evinrude / 18 ft Shetland out on the cold UK sea today and yesterday and gave it some WOT and it went very well. Both times on restarting to get it on the trailer it was very rough on idle and wouldn't rev as it does normally, at higher RPMs it was fine. When I got back i pulled the plugs and the lower one was wet, with water I think (kind of a milky coffee coloured look).. I cleaned them and ran it in the dustbin and it went much better. If I run it solely in the bucket (ie at lower speed) it is always fine so it looks like it is a problem caused by running at higher speeds.

Having searched the forum the following could be the problem..

1. Water in from the Exhaust gasket / plate.
2. Water in from the Head Gasket
3. Maybe something to do with reed valves somewhere? (a thread I didn't quite understand)
4. Water coming in through the carb, from being splashed in (unlikely i think as the cowling prevents it) although a badly placed ladder does splash some when its on the plane....

My question is, is this a reasonable set of reasons and are there more?

thanks in anticipation

David

 

[steelespike]

Re: 35hp cappucino plugs

Your on track My first guess would have been a head gasket.
You could try a compression check.It might show something.
If it is easy to take the exhaust plate off take a look there.

 

[mikesea]

Re: 35hp cappucino plugs

reed valves would have nothing to do with it,and as you mentioned the carb cover is likely not it .You may have a head gasket that is leaking,or the exhust plate.it would be a good idea to check the cylinder compression,if you know a mechanic to borrow one or purchase at local automotive parts store.You could also change the head gasket as precaution,it should not be costly,I suggest you check the cylinder head for warpage by placing a piece of 80 grit wet and dry sandpaper on a piece of marble or glass(insuring flat surface)and pass the head back and forth a few times,then note if there are spots on the mating surface that arent getting sanded,this will show uneven surface.

 

[Phatslax]

Re: 35hp cappucino plugs

Thanks both- will start by replacing head and exhaust gaskets and go from there....