Merc 150 lost top end power

[Hasbeen]

Ok, Now it is my turn to ask a question! Went out on the lake this afternoon to do a little Bass fishing, Caught a couple nice ones so decided to go across the lake to pick up a buddy! Now the Bad news, Just got up on plane and started to trim out and I felt a little shudder and the beeper of death beeped twice then stopped! I imeadiatly turned of the power! When the boat settled down I turned on the key and the beeper beeped as usual and it started right up, idled fine, was a little doggy getting up on plane but did, but it felt rough at higher RPMs, No beepers, plenty of oil in the reseviors!<br />Now the good news, When I got home I pulled the plugs first and they were a little rich looking, no metal, Disconected the coils and did a compression test at WOT, All six were 120 give or take a pound!<br /><br />Any Ideas??<br /><br />Hasbeen

 

[y2j]

Re: Merc 150 lost top end power

could be a fuel delivery or electrical problem of some sort.. I like to deal with older motors (30+years) keeps it nice and simple for me ;D

 

[CU2NITE]

Re: Merc 150 lost top end power

Make sure you are getting spark to all cylinders. If one is not fireing swap coils to see if the problem follows the coil. If that checks out test your stator and trigger with a meter, if that is all good change the packs. I had the same symptoms and my problem was the powerpacks. Were your rpms down from normal at full out? I lost about 1000 rpms with my problem. If you don't have a spark problem I would suspect a fuel related problem. Good luck.<br />CU<br /><br />---------------------<br />RUNNING THE MOTOR WHILE LISTENING TO THE HORN WILL MAKE YOU MORN!!

 

[Hasbeen]

Re: Merc 150 lost top end power

Will the beeper go off for reasons other than oil related issues???<br /><br />Hasbeen

 

[The Marine Doctor]

Re: Merc 150 lost top end power

Your beeper will go off for No oil...Low oil...Over Heat.<br /><br />TMD

 

[Hasbeen]

Re: Merc 150 lost top end power

Just went down to the local Mercury dealer and snuck into the back door and talked to the head mechanic! His thought was that one of the switch boxes went bad! He said that the reason the oil beeper went off is that it gets a signal from the box that tells it that the engine is running! If that power supply goes away it will tell the warning systen that the engine is not running and it will go off! Thats why the double beep! I think I explained it right!! Does this sound feasable??<br /><br />Hasbeen

 

[greasemonkeyozi]

Re: Merc 150 lost top end power

You can know for sure if your switchbox has went bad. Its all and well if your getting spark to all plugs, if so, try this scenerio. What until it gets dark, then inspect your spark to all plug wires. Make sure there is an even blue spark to all plugs. During the day its hard to determine good equal spark to a weaker one unless you stick your toung to it or something. Thats the first sighn of a switch box or a coil going bad.<br /> Wouldnt hurt to check timing as well, but my moneys on your switchbox as the doc said.

 

[Hasbeen]

Re: Merc 150 lost top end power

When I got home tonight I put a timeing light on all the plug wires and got a flash from each one!<br />Actually took the boat out but still runs the same! Only run up to about 4500 RPMs, and sounds rough! Pushed in the enrichment valve once just to see what would happen and it tried to stall out! <br /><br />Would there be spark to all cyliders if a switch box was bad or do they lose spark under load!!<br /><br />Hasbeen

 

[CU2NITE]

Re: Merc 150 lost top end power

Make sure you not getting spark arking over from one of the coils or plug wires. This will also cause a loss in rpms. This will normally happen at the base of the plug wire where it enters the coil. Good luck.<br />CU<br /><br />-------------------<br /><br />RUNNING THE MOTOR WHILE LISTENING TO THE HORN WILL MAKE YOU MORN!!

 

[ugalboogala]

Re: Merc 150 lost top end power

Before you jump into all the ignition system,I would recommend that you take look at your ignition switch first.Pull your control box and do a continuity test on your ignition wire .While its hooked up jiggle the switch around an watch the meter.Ill assume that you get a 2 or 3 beep warning every time you turn your switch on? Good Luck!

 

[Hasbeen]

Re: Merc 150 lost top end power

could you be a little more specific?<br /><br />Hasbeen