merc. inboard engine problems

[chuckonaol]

I have twin merc. 470/170 hp engines, one runs great,the other runs perfect at idle, in or out of gear,dies immediately if I give it any fuel at all.I have checked the points,cleaned and reset them to .022 by the book,replaced the rotor,cleaned the cap,ect and no difference is made.Checked the timing-ok.Both engines have 2 bbl carbs.Rebuilt the carb on the engine acting up,ran ok for a short time and back to run at idle only.I am at my wits end now not knowing where to go next.HELP PLEASE> engine ser.# 5574306 1980-82 . This problem developed after the sea water pump went out which I repaired and engine overheated.I let it cool down for 2 hrs before replacing lost water in cooling system, ran ok , put back on trailer,next day it started acting up.Sea water pump now works fine after rebuilding and no longer overheats.No water in oil, no water leaks.

 

[Alumarine]

Re: merc. inboard engine problems

I don't know much about these things but maybe a compression test/leakdown test would be in order.<br />Someone else probably can help.

 

[Don S]

Re: merc. inboard engine problems

Remove the flame arrestor, and with the engine turned off, operate the throttle and see if gas is squirting into the carb. (Checking the accelerator pump).<br />Check the fuel pump pressure.<br />Cleaning points, and setting points with a feeler gauge is a waste of time on a marine engine.<br />Replace the points and do the initial setup with a feeler gauge, then use a dwell meter to get them properly set, they you must reset the timing as dwell affects timing.