Hi all!<br /><br />As season here in Sweden is ongoing so is my engine problem....<br /><br />My problem is that ive lost like 4knots since last year.<br /><br />What has been done!<br /><br />1/ Carburator rebuilt by marin workshop. At first it only ignite at full throttle but it never start, so i had it returned and he adjusted the float level.<br /><br />2/ Whole electrical system replaced, Cap, rotor, coil, spark-wires and sparks. Timing set at 8degres.<br /><br />3/Fuel filter has been replaced. <br /><br />So, with all this done it should go better or atleast same as last year.<br /><br />My engine is a Mercuiser 5.7 -91 rebuilt -01. Carburator is a Rochchester 4barrel. <br />rpm is 600-700 at idle and at 4400-4600 full throttle. It runs very smooth at idle and sparkplugs are looking shiny and new after aprox 10h running. <br /><br />Im thinkin that ive lost few knots its not running as it should, also the tachometer goes +/-200 rpm randomly, not all time tho.<br />Earlier this year i also got a mysterious knocking sound from lower region of enginge. It sounded like loose part being smashed around by the crank. But now its all silent again.<br /><br />Is this a tune in problem or what?<br /><br />Thanxs in advance<br />Magnus