Mariner 40hp 2stroke 2cyl. 1999<br /><br />Hello,<br />I have a strange problem with my outboard engine.<br /><br />Idle is sometimes very rough and it stalls.<br />Especially when I go into gear it stalls.<br />Hard to start again if stalled.<br />Everything works fine above idle speed and in gear with gas.<br /><br />- petrol is new<br />- carb is cleaned <br />- compression is ok<br />- idle speed is checked<br />- pumping primer bulk doesn't help<br /><br />What could be the problem?<br /><br /><br />For me it seems to run lean so I adjusted the idle mixture screw for half turn out to get it richer. Now the mixture screw it is about 2 turns out. <br /><br />With this adjustment the engine runs better in idle and in gear BUT after 10 minutes of full gas (engine runs fine) I got back to idle. For the first 10 seconds in idle it runs good but then idle got rougher and rougher and it stalls. Restart is hard and I have to give much gas, when I go back to idle then to get into gear it stalls again. <br /><br />The problem seems to come from the lower cylinder as when I unplug the upper cylinder with running engine it stalls but when I unplug only the lower cylinder it doesn't stall and continuous in rough idle.<br /><br />My dealer thougt that the engine is sucking air and wants to remome a oil seal in the shaft. But I think that there should be petrol coming out if this seal should be worn. But there isn't any petrol coming out.<br /><br />I recognized some water (really not much) inside the engine after full gas. Could this little bit water be the problem?<br /><br /><br />Any ideas are appreciated.<br />Thanks a lot.<br /><br /><br />The lower cylinder seems to be the problem as when I unplug the upper cylinder it stalls but when I unplug the lower one it runs further very rough.<br /><br /><br />Rough Idle <br />Engine stalls in idle and in gear<br /><br />Hello,
