Power loss or miss when Trim used

[Stumpylewis]

I am expereincing an issue with my 96 Mercury 200EFI. When I am running at basically any speed if I adjust the power tilt/trim I get a very noticable power loss. Today it actuall started missing when using the power tile/trim. I suspect it may be related to a weak battery or possibly the alternator/generator.<br /><br />Does anyone have experience with an issue like this? Any suggestions?

 

[johnkc]

Re: Power loss or miss when Trim used

stumpy , check all of the ground conn ections . i am sure that you already cleaned and tightened the battery connections .do you have at least 13 volts on your volt gauge when the enine is running.what is the age & size of the battery .the trim motor may have problems and be drawing alot of amps also .

 

[Stumpylewis]

Re: Power loss or miss when Trim used

Thanks John. I will check all this. The battery is about 3 years old and it would not surprise me for it to be going. I will pull it out and take it and get it tested. If this is not it, what else do you think it could be? I am a fairly good amarture auto mechanic but know nothing about boat motors . Do these engines use a generator or alternator?<br /><br />Thanks,<br />Marvin

 

[johnkc]

Re: Power loss or miss when Trim used

stumpy ,under the flywheel is a stator,it in conjunction with the fly wheel make an alternator {and other parts}

 

[petryshyn]

Re: Power loss or miss when Trim used

stumpy:<br />johnkc has a very important question<br />>What is the system voltage when the miss occurs?<br />While running, the alternator will try to supply the demand of the TNT. This will pull about 1- 2HP from the engine.(pending on size and conditions) This may result in a slight engine rpm reduction, but certainly not a missfire. Extremely low system voltage may affect the EFI system.<br /><br />I've never seen your engine, but I've seen EFI engines bothered by electrical noise (EMI). This was often cured by putting a .1uF 50v capacitor across the offending motor or component. Check with the dealer....could be a service bulletin out by now. The more wear on the brushes, the more electrical noise broadcasted on the electrical system. This can fool the ECU into many things....<br /><br />I could be way off regarding your problem, but this is a hard thing to find if you have this condition. (just wanted to make you aware)<br /><br />Good luck!

 

[Stumpylewis]

Re: Power loss or miss when Trim used

Thanks guy's. I am going to try the simple thing first. I went out today and bought new brass battery terminals, cleaned all the batteries real goos and charged the batteries again. I will take it out tomorrow evening and run it real quick to see what happens. <br /><br />The RPM reduction when using the trim today was fairly significant. Running at somewhere around 5000 RPM it dropped to around 3500 to 4000 RPM and started cutting out (I hate to say it miss-fired but it was pretty rough)when using the trim. Funny thing is that when I first put it in the water I went to a couple fishing holes and on the way to them it was fine. The third time I cranked and ran it is when the problem appeared. I did have a couple really dirty terminals that I did not realize were that bad. I'll remove and get the cranking battery tested tomorrow as well if the cleaning does not work. <br /><br />Anyway, I just finished charging and replacing and cleaning terminals so I will find out tomorrow. Thanks again for the replies. I will let you know what happens and may be asking more questions (hope not).<br />Thanks,<br />Stumpy

 

[ODDD1]

Re: Power loss or miss when Trim used

Stumpy, these efi's need a clean reliable source of power for the computers to do their job...too little volts, too many volts, and the motor dont run...when running on plane, the up side of your trim can draw 90 amps....your charging system makes 40 amps...the extra power neede comes from the battery...now, either the well is goin dry [need a new battery] or the power cant get to the motor, like a bad connection....

 

[hondon]

Re: Power loss or miss when Trim used

Im with ODD on this one,but would encourage you to bite the bullet and buy a new battery.Three years is alot for a battery in the evironment that we use them in.You have an EFI motor that has a throttle possition sensor that reads VOLTAGE.If that battery is marginal it will make your TPI go wacky.All other suggestions certainly apply.

 

[petryshyn]

Re: Power loss or miss when Trim used

Stumpy:<br /><br />you still haven't answered the most important question of the day!!<br /><br />>What is the system voltage when the missfire occurs?(have a look at voltmeter when using tnt)<br /><br />until you answer that....you're shooting in the dark...

 

[Don Gregg]

Re: Power loss or miss when Trim used

hi...Just a little more about your problem and maybe a clue where not to look? I have a friend with a 21' cuddy that has a Yammaha I/O 350, carberated engine in it that does the same thing. His only seems to do it at full throttle so maybe you guys are over stating this problem and looking in the right system (electrical)at the wrong places??? Sounds to me like I'd look at the trim connections first and maybe the trim motor after that? Maybe try to hook up a Amperage gauge to the trim/tilt motor?? Amperage is the true indicator of how much power you are drawing to make it work so I think that is where I'd look? hope this helps! good luck...

 

[DJ]

Re: Power loss or miss when Trim used

Schematic's got a good point. If your voltage drops say below about 10.5. The automotive electronics do not like that.<br /><br />Could be many reasons for the drop. Most likely poor connections.