Evinrude 8hp Yachtwin

[ceg79]

I need a little advice....I have an 1998 8hp Evinrude yachtwin long shaft that will not start. It has not ran in almost 10 years. Replaced the water pump impeller and attempted to run. It is getting fuel (wet plugs) and spark. I then ran a compression test and got around 30 lbs. on the bottom cylinder and 0lbs. on the top. Where should I go from here? I haven't messed with the internals on an outboard before but am very good with automotive and small engines so I would like to attempt a repair myself. Any advice would be greatly appreciated.

 

[oldcatamount]

Re: Evinrude 8hp Yachtwin

Is the head discolored? If not, chances are good the head gasket may be bad. If it is discolored, chances are good the motor has been overheated and it would require a tear down to repair. Did you have a reason for replacing the impeller? Try the new head gasket first, if the compression comes back, and it will run, do a de-carb. Motors that sit for that length of time, more often than not, need new gaskets and/or seals.

 

[ceg79]

Re: Evinrude 8hp Yachtwin

There is no discoloration on the head. The impeller was changed just to be on the safe side. I will pull the head off and check it out. On an outboard will I be able to see any bad spots on the head gasket if that is what it turns out to be. Thanks

 

[boobie]

Re: Evinrude 8hp Yachtwin

Once you pull the head post a pic of the head gasket and the cylinders.

 

[ceg79]

Re: Evinrude 8hp Yachtwin

Here are some pictures of the head and cylinders. Something that doesn't look just right is on the head. On the top cylinder of the head it looks like there is a small piece missing. You can see it in the close up picture.

 

[boobie]

Re: Evinrude 8hp Yachtwin

You need a new cylinder head and gasket. The gasket is blown and a piece is missing out of the head where the head gasket seals.

 

[ceg79]

Re: Evinrude 8hp Yachtwin

Thats what I thought. Thanks

 

[the machinist]

Re: Evinrude 8hp Yachtwin

You might try building that divit up with some metal impregnated epoxy (can't remember the name right now). It might not hold over time, but what have you got to loose? At least that would give you some idea of compression in that cylinder.

 

[boobie]

Re: Evinrude 8hp Yachtwin

Putting epoxy in the divit is an idea for checking compression but it won't hold once you fire the motor up.

 

[raczekp1]

Re: Evinrude 8hp Yachtwin

i would do aluminium welding and grind surface at ato repair shop,.
its only one way to repair this head