Mercury Outboard

[Ken Cameron]

We have twin Mercury Optimax 135 motors. The port engine runs perfect. The starboard engine is about to drive us crazy. When trolling the check engine light comes on every 3 to 5 minutes. Placing the throttle in neutral clears the alarm but it comes back. The dealer has placed the computer on the engine 5 times but cannot find what is wrong. Also the engine overheating light comes on at times but the motor is not hot. Any ideas or suggestions?<br /><br />Thanks,<br /><br />Ken

 

[ODDD1]

Re: Mercury Outboard

kEN, IF THE AIR COMPRESSOR OVER HEATS IT WILL ALARM THE SAME AS AN ENGINE OVERHEAT...IF THESE MOTORS ARE ANYWHERE NEAR WARRANTEE HAVE THE DEALER GET A TECH REP FROM THE FACTORY DOWN TO HELP...

 

[pmaier]

Re: Mercury Outboard

I know this is an older post, but in case someone is interested...<br /><br />I had the same issue with my 135 Optimax 1999. Back and forth to dealers several times. Finally contacted Mercury directly, and they said it was a known problem with weak springs in the Throttle Position Sensor. They gave me the part number on the phone and to have the dealer replace it. Worked fine for the next year and a half. Then it reoccured. I've since ordered a manual. Guess I'll figure it out myself instead of letting the marina figure it out on my time and money.<br /><br />Dealer kept saying that the ECM couldn't handle the range that the TPS was producing and that Mercury should really redesign the ECM to handle the error.<br /><br />My gut feeling, nothing wrong except loose throttle cables or something like that.

 

[Hooty]

Re: Mercury Outboard

Thanks for bringing that back up. Good intel. Everybody likes a happy ending.<br /><br />c/6<br /><br />Hooty

 

[bret walters]

Re: Mercury Outboard

we need a little more info. which check engine light , the gauge has 4 different lights. also if the dealer has had ddt tester on the engine 5 times there is readable history. if the engine ecu sees enough of a problem to turn on a warning light it will record a fault code in ecu memory. it may not be an active fault when hooked to ddt but it will be in history. <br />throttle cable tension must be correct and control box in good condition. there can be no play in throttle arm against stop.<br />early tps did have problems.please post with more details.

 

[pmaier]

Re: Mercury Outboard

Me again,<br /><br />Read your comments and will note which check engine light comes on. I know it is not the low oil or temp light. I believe it is the check engine light. It is accompanied by a constant beeping. Both of which are cleared when returned to neutral.<br /><br />It has only been on the ddt (that I have seen) once and it was reporting at the time a problem with the TPS (throttle position sensor). The dealers may have had it on the ddt at other times, but I wouldn't know. As mentioned it was replaced but the problem does still occur.<br /><br />I have received the Mercury Manual that I ordered and in the next two weeks will go through the throttle adjustments. I have a gut feeling that this is the key.<br /><br />Any other details you guys want me to check into ?<br /><br />Phil