2000 Mercury 115--Cant get cranked

[ldolan]

Having a time with this dang motor. I know these motors are hard to start. In the last month I have had the carbs cleaned and have had it running. About a week ago we had it running ok; I let it sit a week and tried again. Couldnt get it going. Took cowling apart and realized we had pinched the main fuel line when we put the lower cowling on. I fixed that problem and it cranked and ran fine. Now this week I cannot for the life of me get it cranked. I can choke it with the enricher and it will fire up for 3 to 5 seconds and just die. I can choke it again and it will repeat the same run and die process. I need some suggestions please?

 

[ldolan]

Re: 2000 Mercury 115--Cant get cranked

bump

 

[ldolan]

Re: 2000 Mercury 115--Cant get cranked

bump. really need some help

 

[ldolan]

Re: 2000 Mercury 115--Cant get cranked

bump

 

[oldgradywhite]

Re: 2000 Mercury 115--Cant get cranked

1# When your carbs were cleaned did they clean the with a hydrosonic bath, yamaha carb dip or jest carb cleaner. Carb cleaner does not work any more with e85 in the gas.
2# Whats you compression?
3# Do you have spark? on all cylenders?
4# Are you getting fuel sounds like you have a bad fuel pump?

 

[ldolan]

Re: 2000 Mercury 115--Cant get cranked

Not sure what chemical he used to clean carbs. But it cranked fined after he did it. Have only had it on the hose since. Havent ran it more than 20 minutes since it was cleaned.

Not sure of compression---would poor compression stall motor after a few seconds of being cranked?

Im assuming I do--but havent checked. It doesnt seem like its missing when it fires up. (wouldnt it run if one or two were not firing?)

I took fuel hose off at pump exit valve and fuel is coming thru--i also tried pumping the bulb once it fired to attempt to keep it going.

Should i check compression and spark bfore i continue or could something else be the cause?

thanks

 

[trendsetter240]

Re: 2000 Mercury 115--Cant get cranked

Sounds to me like it may be an air leak in your fuel line. Possibly from when you pinched it with the lower cowling.

I would check the fuel line you pinched along with all other fuel connections at the carbs for leaks, cracks and air-tight connections.

If it starts when you choke it and then dies right away you are not getting enough fuel.

 

[ldolan]

Re: 2000 Mercury 115--Cant get cranked

As you can tell I am, by no means, a mechanic. But I was thinking the same thing that I am not getting fuel to the carbs after I the "choked" fuel is used up. I do not see any fuel leak and I have replaced all tie straps that secure the fuel lines. I just dont know where to look next. I tried pumping the bulb in an attempt to keep the fuel flowing but it doesnt work.

 

[trendsetter240]

Re: 2000 Mercury 115--Cant get cranked

Is this a 2-stroke or a 4-stroke motor?

 

[sschefer]

Re: 2000 Mercury 115--Cant get cranked

Fuel spark and oxygen are the components you need to keep that motor running. Sounds like there's enough fuel and oxygen even if it's not perfect to keep it running at least rough.
I'd be troubleshooting the stator, trigger, switchbox and coils. Sounds to me like its starting lean and then flooding out. A very typical scenario for weak spark.

Start with a spark tester. If the spark is weak then the trouble shooting paths in the service manual will get you to the faulty component. If spark is strong then continue on your trouble shooting of the fuel system.

 

[ldolan]

Re: 2000 Mercury 115--Cant get cranked

It is a two stroke.

Is this a 2-stroke or a 4-stroke motor?

 

[ldolan]

Re: 2000 Mercury 115--Cant get cranked

I put new spark plugs in last year. I just took them out and they look very black and worn. Could replacing them possibly help?

Fuel spark and oxygen are the components you need to keep that motor running. Sounds like there's enough fuel and oxygen even if it's not perfect to keep it running at least rough.
I'd be troubleshooting the stator, trigger, switchbox and coils. Sounds to me like its starting lean and then flooding out. A very typical scenario for weak spark.

Start with a spark tester. If the spark is weak then the trouble shooting paths in the service manual will get you to the faulty component. If spark is strong then continue on your trouble shooting of the fuel system.

 

[ldolan]

Re: 2000 Mercury 115--Cant get cranked

bump

 

[pointandshoot]

Re: 2000 Mercury 115--Cant get cranked

new plugs couldn't hurt any...and if they look worn and grungy then they are probably past their prime and going to need to be replaced anyways. also how old is the fuel? if its more than 6 months old and was stored outside there is a chance some water is in the gas and won't want to burn like clean fresh gas. try rigging up a jerry can with fresh fuel. you can also try squirting some premix in the spark plug holes when the plugs come out. it does sound like a fuel issue to me (running rough for a few seconds and dieing). what about your fuel filter? again, a cheap replacement part that might not be a bad idea replacing anyways if it hasn't been done for a while.

 

[ldolan]

Re: 2000 Mercury 115--Cant get cranked

what does the premix in the spark plug holes do?

 

[109jb]

Re: 2000 Mercury 115--Cant get cranked

Just making sure but you do have the fast idle lever up when starting right?

 

[pointandshoot]

Re: 2000 Mercury 115--Cant get cranked

premix in the cylinders basically bypasses the carbs on the fuel side of things (for all purposes), and ensures that there is fresh gas to be burnt in the cylinders. so if you squirt premix in each cylinder reinstall the spark plugs and it fires up for a sec you can assume that its a fuel issue of some sort. and if your really lucky it could be enough to "jump start" you motor. you never replied how old you fuel is and if its been stored outside. you'd be amazed how many lawnmowers i've looked at that wouldn't start and all they needed was fresh fuel and purred after that. anything that only gets used for half of the year should be stored properly with fuel conditioner and fogging oil be it a lawnmower, motorcycle, or outboard. for a few dollar and not much work its going to save a lot of grief in the long run. change the plugs and make sure they are gapped to spec.

 

[CharlieB]

Re: 2000 Mercury 115--Cant get cranked

Remove the air box, adjust the trim level, shift into gear and open the throttle wide open.

Watch inside the carb throats while you squeeze the primer bulb, look for ANY fuel leaking into the carb throat, there should be NONE. Return the throttle to idle before attempting to start the motor. If any carb was leaking, disassemble that carb and reset the float level. Or return the motor to the shop that rebuilt the carbs.

Disconnect the fuel line and pump an half cup into a suitable container and let it sit for 10 minutes to 'settle'. Look at it carefully, hopefully there will NOT be any 'beads' of water in the bottom of your container. If so, install a water separating filter.

If ANY water was found in your sample, remove the float bowl drain plug froom ONE carb, use rags to soak up the spilled fuel, pump the primer bulb (after you have installed the water separating filter) to 'flush that carb, reinstall the drain plug and pump up the fuel again. Repeat for each carb.

 

[ldolan]

Re: 2000 Mercury 115--Cant get cranked

Thanks, I will try this next weekend. Im a high school coach and my spring break is now over. Maybe I can get it rolling next weekend.

Remove the air box, adjust the trim level, shift into gear and open the throttle wide open.

Watch inside the carb throats while you squeeze the primer bulb, look for ANY fuel leaking into the carb throat, there should be NONE. Return the throttle to idle before attempting to start the motor. If any carb was leaking, disassemble that carb and reset the float level. Or return the motor to the shop that rebuilt the carbs.

Disconnect the fuel line and pump an half cup into a suitable container and let it sit for 10 minutes to 'settle'. Look at it carefully, hopefully there will NOT be any 'beads' of water in the bottom of your container. If so, install a water separating filter.

If ANY water was found in your sample, remove the float bowl drain plug froom ONE carb, use rags to soak up the spilled fuel, pump the primer bulb (after you have installed the water separating filter) to 'flush that carb, reinstall the drain plug and pump up the fuel again. Repeat for each carb.