95 merc 115 wont run without holding wide open

[daniel11077]

the motor died slowing down going across the lake. i changed all the fuel lines and still nothing. i also redid the fuel pump. this is strange how it will start while it is wide open and run but once you start lowering the rpms it dies immediately. it is getting plenty of fuel. you can drain the carbs and fuel drains out of the bowls. when it is running it runs horribly. i know that on a 115 4stroke that under 1500 rpm it only runs on 2 carbs and then above that all 4 open up. i need some help with this one. i have changed all that i can think of. please help if you can.

 

[emzle]

Re: 95 merc 115 wont run without holding wide open

Daniel. not that I'm an expert on this, but I did just get my 115 running after 4 weeks of pulling hair. 1 st thing. Check that you are getting spark on all 4. It idles on cyl 1 and 2 until 1800-2000 rpm, then the fuel mixture is rich enough for 3 and 4 to combust. I had the opporsite problem, wouldn't idle. First I rebuilt the fuel pump, then noticed I had no spark on 1 and 2, but 3 and 4 were ok. It ended up being a CDM on #4. Got spark, reset the idle mixtures on 1 and 2 and went fishing this morning I can share more of my troubleshooting escapades if needed. But at this point, spark, fuel and compression are the magic words, along with a manual (mechanic's best friend)<br />mark