HPBCANADA.COM

I dont know if its common knowledge, but there was a service bulletin for 56 oval port engines regarding water cooling issues causing
middle cylinder problems.. apparently the middle cylinder was not very well cooled. !!!

The remedy from omc was to drill a hole of 5/16th just through the first wall of the block behind the exhaust cover.
here is the diagram that shows where to drill, also there is also a newer design exhaust cover and gasket.
the newer cover part number was 343864

anyone rebuilding or racing one of these might be best to check to see if their engine has been rectified already.
if not it is a very simple thing to do.



Hope it helps anyone using these engines.
.

the fix is to move the tell tail hole from the side to the top to elininate air pocket.

Would this be correct?

http://www.ebay.com/itm/1994-OMC-Evinru ... a2&vxp=mtr

the cover Houndog has put a link to is the old one, NOT to be used.
the replacement numbers start at 343864 and are to be used with a newer style gasket.


the tell tale movement to the top of the bock was I believe a different bulletin.
the majority of the oval ports came with the tell tale on the top after a certain date.

I will take a few pictures of the inside of the later style cover and try to see what the difference is.
I know 100% that one of my 1995 covers are the later style, will check the spares engine.