View Full Version : troubleshooting merc. 8 horse 4 stroke
Irie1
10-30-2002, 07:36 AM
2000 merc took a dive. It was working fine for 6 to 7 hours of back plugging. We decided to load up and move. We got to the next hole and the kicker would start, but would not idle down. it's responsive in the higher rpms., but sounds real doggish in the lower rpms.and won't stay idling in gear. We pulled the plug and switched to a new one, they both were fouled good. Got home and tore into the carb and couldn't find anything noticeably wrong.
Is there anything else that would go bad ?
Smily
10-30-2002, 08:02 AM
Hi Irie1,
Sounds like Idle jet's are clogged. I have not worked on the 4 stroker's but that's what it sounds like to me. Good luck in finding the probleme.
Right now I have the opposite problem. It will idle fine and go about half throttle then after that want to die. Also a fuel problem.I have taken the fuel filter off to find a lot of setiment in the fuel filter in mine. How about yours? Have you check your filters lately and find anything?
:smile: Smily :smile:
Irie1
10-30-2002, 08:05 AM
spews fuel fine and filter is clean.
graybeard
10-30-2002, 08:08 AM
Sounds like you have at least one piece of crud in your carb. Rev your motor to see if you can blow it through. If that doesn't work, you can try a gas additive to try and disolve it. (This is assuming you don't know how to take apart the carb and clean it). Sometimes it helps to screw in the idle screw and then back it out to where it was. Sometimes that will help dislodge the piece of crud.
Try the same with the mid-range screw.
You can also uncrew the drain plug on the carb and check for crud.
And you can check the mainjet to see if it is plugged.
If none of the above works, take it to the shop. Unless others have a better suggestion.
Good Luck
graybeard
10-30-2002, 08:11 AM
If it is spewing fuel, it means that your floats are probably stuck. Thats an easy fix. just tap the bottom of the carb with a plastic screwdriver handle and try to free them up. If that doesn't work, take the bottom of the carb and they should dangle free.
graybeard
10-30-2002, 08:14 AM
Smily... sounds like your main jet is plugged. If you can locate it, take it out and clean it. Don't damage it by trying to clean it with a pin.
Smily
10-30-2002, 08:34 AM
Thanks Greaybeard,
I was cruising along last friday and at the end of the day it just bogged down on me. Pulled the fuel filter off and seen all the setiment in it. CLeaned the stuff out and reassmbled. Started it the next morning ran fine. Got to the dock and it ran fine. GOt out to open water and it did the same thing again. At the end of a couple of hours it cleared itself out. Can't wait to run it again and run that fuel tank out of gas and get a new one. I think there must be a bunch of setiment on the bottom and no real way to clean it out.
:smile: Smily :smile:
1pump
10-31-2002, 12:58 AM
smily-
Getting your gas in Gresham? If so, it's an ethanol area, 10% blend starting 10/15. Nov 1 it'll drop to 8%. Ethanol (oxygenated) gas will knock crud loose from your tank and into your filter. Screw DEQ and get your gas in Vanc!
Irie1-
Vacuum leak? Just my .02
Irie1
10-31-2002, 03:13 PM
thanks! Still trouble shooting, Think'n shooting trouble