Re: 7.4 Mercrusier
New to this forum, I have a 1997 7.4 mercrusier. Runs great. But I was out yesterday and noticed it smoking just a little. Its was black. Still ran great on top end and ideals good. Running a little rich?? any Ideals?? Thanks.
Howdy,
You have an electrically operated choke.
Before you start the engine a small spring located on the side of the carbureter applies closing pressure on the choke plate.
When you turn on the ignition key, it applies 12v power to that bi-metallic spring causing it to slowly heat up. After a small amount of time the spring (when it gets hot enough) opens the choke. By then the engine is pretty much warmed up and doesn't need to be "choked"....If you only operate your boat in warm weather, your choke requirements are a lot less and you may need to adjust your choke to open a little quicker......
Yours may be adjusted incorrectly, the wire may have broken or fallen off the connection on the carb, the spring has broken, or the actual mechanism has jammed, etc.
It's a simple system and the adjustment is also simple.
Get yourself a copy of the Merc service manual for your engine look in the troubleshooting section....There's an explanation of how to adjust or trouble shoot it.
The Mercury service manual outlines the procedure,
http://www.boatfix.com/merc/Servmanl/16/16cov2_1.pdf
On the other hand, if you live in an area where you only boat in warm weather, you may be able to just adjust it out of the picture and disconnect it. (that's what I did with mine)
"Your mileage may vary"
Regards,
Rick
