First of all just wnt to say this a great board with answers to almost any question.<br />I just havent been able to find the answer to my question, so here it comes.<br /><br />I have a Mercury 50HP 4-stroke with carburators from 2002, has run about 200 hours and always maintained, where I have two problems.<br /><br />Problem 1.<br />The engine i leaking oil and after a lot of cleaning and inspection I have found that the leak is from between the crank case cover and the cylinder block, so I will probably need to remove the crank case cover and apply new sealant, but do I have to remove the whole power head before removing the cover or can I do it with the power head in place, it would make it a lot easier.<br />Should I be worried that such a new engine has this kind of leak, and what caould have caused this to happen?<br /><br />Problem 2.<br />The engine starts fine and runs fine until it reached about 4600-4800 rpm, then it looses power and and starts going up and down in RPM.<br />If I give it full power it will go to about 4600-4800 RPM and start going very uneven, and will have no pulling power, if I take the power of to quickly the ingine stops completely, but starts easily again.<br />I am using new fuel, the tank is vented and the connections on the fuell line are new.<br />My own best guess would either be the fuel pump or the carburators.<br />But I would prefer not to remove the carburators if there is no need, I dont want to disassemble to much of such a new engine.<br />You must have in mind that outboard engines and spares are very expensive here in Denmark, a 50HP outboard cost around 10.000 USD, so we have to take care of our engines and dont just exchange spares for the fun of it.<br /><br />Please excuse the English if it's a bit hard to understand.<br />Thanks in advance.<br />Regards Brian