1983 Johnson 70 dies when accelerating

bass101

Cadet
Joined
Apr 29, 2016
Messages
7
I've had this motor for 3 years now and its never run right. It idles fine and runs great at WOT but bogs and dies at mid range unless i use the enrichment solenoid. Here's some things I've tried.

1. Cleaned carbs, and yes they are clean

2. Sync and link. I followed my OMC manual to a Tee

3. Changed primer bulb and hose and used a remote fuel tank.

I've read of a service bulletin Evinrude #1144 on here that describes my exact problem. But i can't find it online.
 
Last edited:

flyingscott

Fleet Admiral
Joined
Apr 8, 2014
Messages
7,985
I had a 1979 model with the same problem. I changed the low speed orifice to 2 sizes smaller on the recommendation of the dealer. There is also a service bulletin for venting the prop to help with that. When I changed the orifice I did lose some idle quality it was worth it. When I accelerated my motor would just fall on it's face. try this
http://forums.iboats.com/forum/engi...ards/85027-service-bulletin-1429-for-evinrude
 
Last edited:

bass101

Cadet
Joined
Apr 29, 2016
Messages
7
Thanks so much! I've read that post you sent before and have trouble opening the service bulletin links they're so small and blurry I can read em. As for the orifices are you talking of the idle air bleed on the top front of carb or slow speed orifice on the top RH back of carb?
 

lmuss53

Lieutenant Junior Grade
Joined
Sep 9, 2008
Messages
1,227
Try pumping the ball while it's acting up, if it settles it down, look to the fuel pump.
 
Last edited:

bass101

Cadet
Joined
Apr 29, 2016
Messages
7
I've tried that and doesn't seem to make any difference. I've also checked compression, 105 on all holes. The carbs have only orifices no needles. The orifice in the top back is a #68 the top front is #42 and the high speed in the bottom is a 52D. This agrees with parts diagrams. I don't totally understand how the air bleed orifice works and for sure which top one it is.
 

flyingscott

Fleet Admiral
Joined
Apr 8, 2014
Messages
7,985
convert
#27 is the low speed orifice. This orifice controls air flow for the idle circuit the larger the # the more air it lets through resulting in a leaner mix. The smaller the # the less air comes through and more fuel results in a rich mixture.
 

bass101

Cadet
Joined
Apr 29, 2016
Messages
7
Ok, that's what i'd concluded just making sure we are on the same page. I have 4 different sizes of orifices I've tried #38 through #44 the carbs came with #42. none of that seem to help. Like I've said this thing has puzzled me for 3 years. I've read tons of threads and tried about everything it's becoming a boat vs me thing by now :lol: I found and read the SB on venting the prop I have an old one I might try it on first. Keep the suggestions coming really appreciate it!!
 
Top