Poor Running 4.3

gamparano

Recruit
Joined
May 9, 2012
Messages
4
Have a 1987 Eddtide Rivera 18 ft w/ OMC Cobra 4.3L. Have replaced the lower unit with a brand new one from SEI. It was very difficult removing pulling shaft out.
Same with installing, but got it in.
Started up the boat cranked up in a couple of tries. Idle is at 600 rpm, runs very smooth at idle. Just fueled up, was empty. Use Premium fuel.
Shifted into forward, engine begins to spurt and begins to run very rough and stalls. Tried a few time and did engage a couple of times and began running rough then kicked on ran very well,No clunking going into gear, very smooth shifting.
Shifted into reverse and shifts very smooth, no noise or clunking runs great.
Added gear lube, changed oil, oil filter, checked fuel filter looks very clean. Fuel filter in Carb is bronze, looks very clean
All this was done on trailer with muffs
Before changing lower unit boat ran like a dream. Easy start up, shifting great, throttled up great.
What am I missing or what should I do?
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,465
Ayuh,.... Welcome Aboard,... It sounds like ya got a Merc Alpha conversion on yer OMC,..?? Right,..??

If so,...
I'd look to the shift interrupt switch, 'n possibly the lower shift cable draggin', causin' the switch to move, breakin' down the ignition circuit,...
 

gamparano

Recruit
Joined
May 9, 2012
Messages
4
I was troubleshooting problem and starting adjusting the small module that has a small arm, that rides over the shifter on the carb. Lubed it, bent the arm a little so it would push small button in and it worked fine after. I am going to replace that lil module. Have it in the shop now to have the transom inlet water hose replaced, and he's going to replace the module. Check the shift cable too, make sure that is not the problem also. That's for the input
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
11,798
Sounds like your ESA is sticking on in Fwd gear. It is only supposed to engage when shifting from in gear to neutral not when shifting into gear.
You need to go over the shift cable & ESA adjustments.
 
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