Merc 4.3

You know the drill..

Moderators: Redneck_Randy, badmoonrising, lakerunner

Post Reply
Message
Author
User avatar
WaltF
Posts: 4051
Joined: Thu Nov 06, 2008 8:42 am
Location: Colorado Springs, Co
Contact:

Merc 4.3

#1 Post by WaltF » Mon Jun 07, 2010 2:36 pm

Hey All,

My buds got a merc 4.3 n alpha drive on his older 1988 Larson.

H'es complaining that it idles too high, but when shifting from fwd to rev or vs versa, it often dies.
Are there 2 idle controls to be set for that? ie idle and idle between shifting?
He'd like to turn it down so he's not idling around so fast, but doesnt want it to die while flipping back n forth...

I know its not a toon, but i figure some of you smart dawgs in here might know... :nana
--------------------
ImageImageImage
--------------------
'07 22 ft SunTracker Regency 135hp i/o
'02 Dodge 2500, Edge Juice w/Attitude
Colorado Springs, CO.

User avatar
slingshot
Posts: 456
Joined: Thu Nov 13, 2008 7:20 am

Re: Merc 4.3

#2 Post by slingshot » Mon Jun 07, 2010 3:44 pm

Yes, there is an interrupt circuit that cuts ignition for a split second to allow for a smooth shift. Follow your shift cable from the helm to the shift interrupt system. That system should have another shift cable coming from it to the outdrive. You should notice the circuit wires coming from your ignition to the system also. That's as far as I can go w/o a photo of it or being there. Well, at least that's how the system worked on my old I/O.
2007, 2570 Crest LE II
Yamaha F150

User avatar
badmoonrising
Site Admin
Posts: 10066
Joined: Fri Mar 30, 2007 7:04 pm
Location: Chesapeake City, Maryland

Re: Merc 4.3

#3 Post by badmoonrising » Mon Jun 07, 2010 10:13 pm

Carb or Injected ? If carb, what happens is there is a fixed adjustment screw at the carb's base with a lockout plug. After several years the carb plug needs to be removed and the carb idle settings adjusted. I'd also suspect a shift interrupt problem as well as the carb needing tweaking. If EFI, it should be scanned by a pro.
Ed, Cheryl, Ethan and Aspen.
2013 Sun Tracker Party Barge 22 w/90 HP Mercury, "Hellrhighwater 2"
2014 E-350 Extended XLT.
Chesapeake City ,MD

User avatar
WaltF
Posts: 4051
Joined: Thu Nov 06, 2008 8:42 am
Location: Colorado Springs, Co
Contact:

Re: Merc 4.3

#4 Post by WaltF » Tue Jun 08, 2010 11:09 am

Cool! :nana

I will pass the info onto my bud!
Thanks Guys! :thumbsup
--------------------
ImageImageImage
--------------------
'07 22 ft SunTracker Regency 135hp i/o
'02 Dodge 2500, Edge Juice w/Attitude
Colorado Springs, CO.

Post Reply