HELPPPPP!!! Merc 4.3 wont start after warming up. possible carb issue

[bpmcl00]

Just bought a 1990 sportcraft with 4.3 merc 2 barrell carb. the first start of the day is normal. boat will run fine, after a little while the idle starts to drop and unless i give it some gas it will die.

Now after it dies it is near impossible to restart. when i look down the carb there is gas collecting at the bottom and even when the boat is off i still see gas dripping down into the carb.

Anyone else have this problem? Any suggestions?

Thanks

 

[bpmcl00]

Re: HELPPPPP!!! Merc 4.3 wont start after warming up. possible carb issue

BUMP! Can anyone out there help me?

 

[TyeeMan]

Re: HELPPPPP!!! Merc 4.3 wont start after warming up. possible carb issue

Sounds like the needle and seat in the carb iether just shelled out or was improperly adjusted upon installation. That happened to me after I rebuilt my carb on my 3.0L. It wouldn't want to idle, idled rich, and when I shut her down fuel continued to drip into the ventury. Took the carb appart, readjusted the needle, end of problem and she runs like a champ.

Good luck!

 

[bpmcl00]

Re: HELPPPPP!!! Merc 4.3 wont start after warming up. possible carb issue

Thanks tyeeman,

im assuming you had the 2 barrell MerCarb also. was this a pain to work on? iv never worked on a carb before but im extremely good with taking things apart. i figure i shouldnt have too much of an issue. im going to go play with it today and see how it goes!

 

[havasuboatman]

Re: HELPPPPP!!! Merc 4.3 wont start after warming up. possible carb issue

Before you take things apart... (by the way, everybody is good at taking things apart, it's putting them back together that counts)
Is there a strong fuel smell, like it's flooding?
If so, warm it up, remove the spark arrester, and look into the carb. Is the choke plate opening up? If there is, is there fuel dripping in the carb?
Have you checked for spark when the engine wont start?
Check the easy stuff first, before you start tearing into things. You always want know what the problem is before you "fix" it so you don't end up spending a lot of money on a simple problem.

 

[bpmcl00]

Re: HELPPPPP!!! Merc 4.3 wont start after warming up. possible carb issue

Checked choke allready. its working fine. seems like i have a case of flooding. either way i figured i would go through re-check float height. change needle/seat and power valve and see how that does things.

Can anyone else recommend anything else to check while i have the carb off?

 

[havasuboatman]

Re: HELPPPPP!!! Merc 4.3 wont start after warming up. possible carb issue

I'm sorry, I missed your first post. guess I only read the second. Tyee's got you looking in the right direction. No fuel should be leaking past the carb.

 

[bpmcl00]

Re: HELPPPPP!!! Merc 4.3 wont start after warming up. possible carb issue

well got the top half of the carb off. needle and seat look good. im going to readjust float height and see if that will help at all. if not i guess ill swap to the spring loaded needle and see how that works...

Quick question-- when adjusting float height do i measure from inside the carb or flush something with the face of if and measure from there.

If you understand what im talking about do i stick the ruler into the well of the carb and measure or assume flush with the face and measure from there.

Thanks!

 

[havasuboatman]

Re: HELPPPPP!!! Merc 4.3 wont start after warming up. possible carb issue

You measure from the airhorn (the top part you took off) with the gasket on, to the end of the float