Re: Hey marine DR got a question
I'm not marine Dr, but might be able to help,as I have werked on one of those. <br />The silicone is not recommended inside the pump housing, if that is what you mean. Anywhere the silcone can flake or peal away, and become mobile inside your cooling circuit is a no-no.<br />The exaust port plate gasket, sure, provided you do not use too much, it is the right type, can help seal a warped mating face. But milling flat would be better. Your reported compression is low, and barely adequate for proper performance. So much hinges upon compression. The carbs need it to draw fuel from them into the jugs. The pistons need it to give the best 'oomph' possible, and the fuel pump operates directly from compression. And the fuel pump diaphram is the next thing on the list of replacement parts. It was not designed to withstand ethanol or alcohol-blended fuels, and will deteriorate rapidly (I had them fail inside a season one my personal Force, a 50HP model with standard dual-stage pump).<br />The good thing is the diaphram is cheap. It comes by itself, or with the complete rebbuild kit..The latter is rarely required, unless the boat sat unused for a year or so, because the check valves are not as sensative to fuel blends...The rubber diaphram is another story.<br />I keep one in my emergency kit, in case it decides to rip appart underway.<br /><br />When you had the exaust port plate off, how did the combustion exaust side look? Was there a lot of tar-like goo in there? If so, the compression numbers may be reflecting a restricted exaust. This is very common, esspecially if the motor is used at idle much of it's operation, by allready-low compression, or from not decarbing frequently enough.<br />And that last one is allways a guestimate, based upon actual operational parameters like water temp, RPM's, intervals between WOT and idle, and fuel/oil mixture and manufacturers. I use a 'rule-of-thumb' ,every 10 tanks full of fuel (about 80 hours in my operation), and I change plugs then also. Your 'rule-of-thimb' will probably be differentr..I idle 80% of the time due to manatee protection zones imposed by the marine gestapo...If you are at full bore 80% of the time, you may never need to worry about port fouling carbon.
