Can anyone give advice on a 1999 Mercury 125 hp that cranks to slow to start. Voltmeter drops from 13 to 10.?

Question

New battery, fully charged, clean contacts at battery and starter....Cranks very fast with the 4 plugs removed, but not when re-installed.

Answer 1

It is the Starter most likely. Above are some good things to check. Battery Polarity, which I hope you have correct. Though this Engine is Relatively new it can be the Starter Dragging because of the Brushes. What could have caused this is hard to say. A lot of times it is trying to start the Engine with a low battery. You may be able to remove the starter and have a Repair Shop or maybe Autozone can check it. You can fix this if you know a little about Electric Motors, if not, a Starter Repair shop may be cheaper than a Boat Dealer!

Answer 2

first thing is check the battery because it is the easiest and most obvious. a carbon load tester is best. most auto stores will do this for free or a minimal fee. also check and clean the battery connections and where the batter cable attached to the starter and the negative cable attaches to the block. use a wire brush and make sure a good connection is taking place. if all of this fails it has to be the starter and it needs to be rebuilt. the reason it cranks fine without the spark plugs is because not compression is being built up. always remove the negative battery terminal first when working on electircal.

Answer 3

Sounds like you need a new starter. With the plugs removed the engine has no compression, that means that the starter is not under load. With the plugs installed you have resistance(starter under load). Check the battery ground connection for looseness.

Good Luck

Answer 4

A cranking voltage of 9.5 Volts or greater is considered normal on any automobile. So it sounds like the battery's supplying the cranking amps ok needed by the engine.

Answer 5

record of issues to do and verify after a vehicle has been sitting 2 Years; one million or 2 Bottles of gas therapy/Carb.-Injector purifier in the Tank, replace the Oil & filter out, replace the gas filter out, "get rid of the Battery and function it completely Charged, whilst Charged have it"Load examined" for 15 Seconds at 50% of CCA no longer dropping below 9.6 Volts throughout the attempt and which will teach (If it particularly is nonetheless solid) you if the Battery can Take and carry a fee. Are the Battery Cables clean & shelter? verify the Cooling device, after sitting 2 years the Coolant (50-50 clean Water & Anti-Freeze) could get replaced then tension attempt the device for any Leaks. First it particularly is probable a foul Battery + All or a important sort of the products listed Above.

Answer 6

spins fast with plugs removed but re-install slows down shows that you should have good compression, are you sure that the plugs are getting enough fuel to make it start? if so is the carburetor set right?

Answer 7

The battery you have does not have sufficient cranking amps for the application or your starter needs replacement/repair.......??

Answer 8

Battery doesn't have enough umph. charge up the battery, then tryit again. If that doesn't work, replace the battery (be sure to get one with sufficient CCA).

Answer 9

sounds like the bushings in your starter motor are allowing the armature to drag, have the starter motor checked out by a professional

Answer 10

check the Battery for reversed polarity.....ex the positive terminal is neg and Negative is Positive even though marked......guy installed one on my jeep and that happend the manufacture screwed up.