2000 Mercury EFI 175

[burk4384]

Two weeks ago went to lake and motor wouldnt fire up. Went home and it fired right up without even charging the batt. Went out to run it on friday with no problems except the trim got stuck in the down position I have to disconnect from batt to make it stop. I fired it up at 5o A.M on Sat to ensure it would work for tourney. When I arrived an hour later it wouldnt fire up I tried until batt was dead. At the end of the day my trim did the same thing. I charged the batt and it fired up an hour ago. Can anyone help.

 

[Lineman111193]

Re: 2000 Mercury EFI 175

Hey Burk, Try swapping your trim relays when the trim acts up. Both are the same, one is for up and one is for down. Sometimes you can tap relay while pushing motor trim button and it will start working. As far as your starting problem. Is weather very cold, primer bulb hard, engine always cranks easier off a hose than in actual lake water because of lower unit being completely submerged. Need to know, does engine sputter when trying to crank or does it do nothing but turn over. We need a little more info......
Something else might help you, do a search in the archives for the symptoms your engine is portraying, they always have alot of good info. Good luck!

 

[CharlieB]

Re: 2000 Mercury EFI 175

Notice that after you charge the battery that the motor fires up.

Minimum cranking speed 300 RPM to start the motor.

It may sound like its cranking well enough to start but if the battery is a bit too low and won't spin it over 300 RPM the ignition won't fire. But it will keep on cranking until you fry the starter motor.

Trim relays have normally open and normally closed sets of contacts, switching relays may reverse the sticking trim, and draw the battery low enough that it won't crank fast enough to start.

Change both trim relays.

Recharge battery

Check charging system.

 

[Faztbullet]

Re: 2000 Mercury EFI 175

I dont think Mercurys have a minimum cranking speed, just the OMC's. They do have a minimum ECU voltage of 10.5 VDC. If voltage falls below this ECU will fail to fire injectors and sometimes the fuel pump. You have a bad relay so replace as a pair to repair trim problem.