99 Mercury 200 optimax

[mjfpilot]

Engine was running rough so took it in 3 months ago . They changed all the plugs and said one of the air injectors was bad. Also water found in fuel filter so they drained/strained the tank. Ran better after I picked it up. Haven't driven it much since, but the other day finally took it out again. Had to recharge batteries to start. The engine is very sluggish now and is hard to get on plane. Full throttle up I get only 3000rpm and on plane max of 4400rpm. Tops out at only 30 knots...used to get in the mid 40s. It runs smoothly but with a loss of power. Could it be the carb and if so can you add a fuel additive to a 2-stroke? Any help would be greatly appreciated. My last maintenance bill came to 800.00 dollars.

 

[greasemonkeyozi]

Re: 99 Mercury 200 optimax

Make sure the mechanic that worked on your motor put the right plugs in with right gap and heat range. Make sure your fuel/oil mixture is exactly right by the manual.

 

[rabidfish]

Re: 99 Mercury 200 optimax

Mercury's Optimax engines are very complex. There is no spec for oil mixture, it's controlled by the onboard computer(ECM). Also it has no carburetors.(fuel injection) Did the technician do a fuel/air pressure test? Was the fuel 90psi? Was the air 80psi? Do this test at speed on the lake as well as on muffs at the shop... Are any fault codes present? How about a cylinder misfire test? There were some TPS sensor failures. Your engine has 2. if one fails, it will limit the RPMs to about 3500. If they both fail, your engine will only idle.<br /><br />Honestly... you need a "qualified & EXPERIENCED" Optimax technician for this one. Find a dealer who can produce training certificates that say "Optimax" on them. You own probably the best outboard ever built(by anybody) now you need a real mechanic to fix it.... GOOD LUCK!