2000 125 mercury

[ford03]

Yeah i have a 125 saltwater series mercury year 2000. I brought it to a friend this past summer to fix it and it came back in worse condition then i gave it. Right now im having a problem with the RPM's. I can only get it up to 3000 rpm. Ive checked almost everything. Things i have done are checked the timing, tested compresstion, checked all carburators, put in new gaskets, checked spark to all plugs and put in a new trigger assembly?? What am i doing wrong? A friend and mechanic said maybe the stator is bad?? I have put in a new trigger assembly but didnt change the stator. Should i replace it or no? I figured i should ask before i go and spend 220.00 on a new stator. Any help would be greatly appreciated. Id bring it to a mechanic but at 95 dollars an hour i cant afford it. Please help me. Thank you

 

[WillyBWright]

Re: 2000 125 mercury

Check spark while running in the water. You can do that with a timing light. Attach it to each plug wire in consecutive runs. If you lose flash, you lose spark. I wouldn't necessarily suspect a stator problem on a 2000. They had most of their problems 1996 and prior. Chances are better that it's a carb problem or a bad ignition module.

If you're losing spark, the bad module may not be the one that loses spark. They operate in pairs and it could be the other one in that circuit. The firing order will be embossed on the water jacket cover near the sparkplugs. The pairs are the first-third cylinders in the firing order and the second-fourth cylinders in the firing order.

Before running the motor again, I'd suggest draining the carbs, then flushing them by priming the fuel line bulb. If the drain plugs have crud on them, rebuilds are in order. You probably wouldn't need complete carb kits. 99% of the time all you need is carb gasket sets and float valves. Complete kits are expensive and contain a lot of stuff you may be better off of leaving alone.

Try to catch the gas you drain from the carbs and check for water. It's not at all unusual to get water in a boat gas tank. Don't use alcohol additives to mix the water into the gas like you might do with a car. You have to remove the water, usually by syphoning from a low corner in the tank.

 

[ford03]

Re: 2000 125 mercury

Check spark while running in the water. You can do that with a timing light. Attach it to each plug wire in consecutive runs. If you lose flash, you lose spark. I wouldn't necessarily suspect a stator problem on a 2000. They had most of their problems 1996 and prior. Chances are better that it's a carb problem or a bad ignition module.

If you're losing spark, the bad module may not be the one that loses spark. They operate in pairs and it could be the other one in that circuit. The firing order will be embossed on the water jacket cover near the sparkplugs. The pairs are the first-third cylinders in the firing order and the second-fourth cylinders in the firing order.

Before running the motor again, I'd suggest draining the carbs, then flushing them by priming the fuel line bulb. If the drain plugs have crud on them, rebuilds are in order. You probably wouldn't need complete carb kits. 99% of the time all you need is carb gasket sets and float valves. Complete kits are expensive and contain a lot of stuff you may be better off of leaving alone.

Try to catch the gas you drain from the carbs and check for water. It's not at all unusual to get water in a boat gas tank. Don't use alcohol additives to mix the water into the gas like you might do with a car. You have to remove the water, usually by syphoning from a low corner in the tank.

ok so ive checked all spark and all is good. but i think ive figured it out. like i said it wont run up to desired RPM and i believe its my carbs?? When i run the engine i can see that my carbs only open i dont know about a quarter of an inch? my buddy had all the carbs out as did i but i never messed with the linkage that connects all carbs. he put in a new oil pump and was wondering could that have messed up something?? I checked the linkage that connects all the carbs and i couldnt readjust anything on the linkage arm so i dont see how that would have gotten messed up? like i said any help would be greatly appreciated. This engine has my head spinning!! thank alot Eric

 

[ford03]

Re: 2000 125 mercury

Check spark while running in the water. You can do that with a timing light. Attach it to each plug wire in consecutive runs. If you lose flash, you lose spark. I wouldn't necessarily suspect a stator problem on a 2000. They had most of their problems 1996 and prior. Chances are better that it's a carb problem or a bad ignition module.

If you're losing spark, the bad module may not be the one that loses spark. They operate in pairs and it could be the other one in that circuit. The firing order will be embossed on the water jacket cover near the sparkplugs. The pairs are the first-third cylinders in the firing order and the second-fourth cylinders in the firing order.

Before running the motor again, I'd suggest draining the carbs, then flushing them by priming the fuel line bulb. If the drain plugs have crud on them, rebuilds are in order. You probably wouldn't need complete carb kits. 99% of the time all you need is carb gasket sets and float valves. Complete kits are expensive and contain a lot of stuff you may be better off of leaving alone.

Try to catch the gas you drain from the carbs and check for water. It's not at all unusual to get water in a boat gas tank. Don't use alcohol additives to mix the water into the gas like you might do with a car. You have to remove the water, usually by syphoning from a low corner in the tank.

ok so ive checked all spark and all is good. but i think ive figured it out. like i said it wont run up to desired RPM and i believe its my carbs?? When i run the engine i can see that my carbs only open i dont know about a quarter of an inch? my buddy had all the carbs out as did i but i never messed with the linkage that connects all carbs. he put in a new oil pump and was wondering could that have messed up something?? I checked the linkage that connects all the carbs and i couldnt readjust anything on the linkage arm so i dont see how that would have gotten messed up? like i said any help would be greatly appreciated. This engine has my head spinning!! thank alot Eric

 

[WillyBWright]

Re: 2000 125 mercury

So you're not getting full throttle. See if the arm that the throttle cable attaches to is making it's full arc. There will be many adjusting screw stops on it. With the throttle at idle it, the lowest stop should rest on it's pad. As you advance the throttle to full, there will be two more. The one at the top should come to rest first That's spark advance. The one in the mddle should come to rest last. Make sure it's doing both.

The throttle links between the carbs are easy to synchronize. Loosen up all the screws, make sure the butterflies are all closed, then snug the screws again. One of the carbs has a roller on it. Start snugging the screws by that carb and work towards the furthest carbs. It could be fine-tuned better, but that will be pretty close.

The roller needs to be about .020" from the lever when the timing mark on the arm is even with the center of the roller. ( I think spec is .020-.050. )

Finally, advance the main throttle arm all the way full and see if the carbs are opening all the way. The butterflies should be flat or darn close. You adjust that with the throttle stop screw on the main arm. (I think the stop screw for this isn't on the arm, but the arm comes to rest against it. Low towards the front. ) The stop screw should keep the butterflies just barely shy of where they lock full-open.

The smallest screw on the main throttle arm is for adjusting the idle speed. If it wasn't moved, it should'nt need adjusting. If it was, that's where you adjust idle.

That's for a carb job. If the spark advance stop screw was moved, then the max timing needs to be checked.