Need help with idle and WOT

Davis1995

Cadet
Joined
Sep 20, 2020
Messages
23
I have a 1996 70hp Johnson and need help with my idle and wot. I have cleaned my carbs multiple times, replaced spark plugs, new coil pack for one cylinder..got the other 2 coming in this week. I am trying to figure out why my motor wants to shut off in neutral..very frustrating.

also, my engine runs fine until I get to WOT and then it wants to bog down and go in and out. My boat used to go 37-42 and now it won’t go over 28.

another question I have is about the amount of oil residue that builds up on the water line along the back of my boat. Anyone have problems with this? It’s a new thing to me
 

ecu1984

Seaman Apprentice
Joined
Jul 22, 2011
Messages
39
link and sync done on the carbs? when idleing are all three carb butterflies closed and at WOT are all three perfectly opened?
 

Davis1995

Cadet
Joined
Sep 20, 2020
Messages
23
I have a friend of mine that has came and helped me look at everything. He just got done adjusted the carb idle screws this past week. From what I remember is that they are all closed and opened respectively. I’ve been fighting this all year but it works good enough lol
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,047
Do a compression test.----Just for future reference.----There have been issues with # 2 cylinder.
 

Davis1995

Cadet
Joined
Sep 20, 2020
Messages
23
I think that’s the one that I had to change the coil pack on. I’ll check the compression..what do you do if it’s low?
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,047
If you had to / did clean the carburetors multiple times then maybe it was NOT a carburetor issue.----Simple trouble shooting will find out why there is a lack of power now !!----Test for spark as well.----Strong spark is what you want.----The system is capable of jumping a gap of 3/8" or more.
 

Davis1995

Cadet
Joined
Sep 20, 2020
Messages
23
I think that’s the one that I had to change the coil pack on. I’ll check the compression..what do you do if it’s low?
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,047
If compression is low on any cylinder you remove cylinder head to find out why.
 

Davis1995

Cadet
Joined
Sep 20, 2020
Messages
23
Appreciate it. I actually had to change the top cylinder coil..we also did a spark test and had sparks in each cylinder
 
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