1979 evinrude 140. running weird, idle dont seem right. any imput is appreciated

[dom_litty09]

i have a 1979 evinrude 140 that has been giving me issues since late last summer. rebuilt half the engine, carbs cleaned, all new fuel lines, some new gaskets, and it has spark on all 4 cylinders but it just doesnt seem to be running right. i havent taken it out this year to see if it actually goes, last year it would run good for about 5 mins on plane then die and run like crap so i mainly havent taken it out cause i dont wanna get stuck lol. but anyways the idle right now is at about 900, sounds ok. but the timing screw is all the way out (well its about half way in but if it was all the way out it would be touching like it should (see pic). it just seems like that isnt right to me for the timing to be that advanced. when i first got the boat it was sitting perfect where it was now but actually touching like it should. any ideas of whats going on? im hoping to check compression today or tomorrow. but im hoping to get it going soon so i can have it for the rest of the summer. any feedback would help me out. also it seems like the starboard side of the engine is hotter to the touch, idk if that matters or not but just something else i noticed. thanks

 

[emdsapmgr]

Re: 1979 evinrude 140. running weird, idle dont seem right. any imput is appreciated

Usually, the idle screw on that spark advance lever is all the way against the block. You're correct it's probably not set correctly, and probably has advanced timing based on where it is set now. You need to do a sync and link according to the factory service manual specs. Check the spark on all 4 cyls when warmed up. It may not be firing on all 4 cyls. When running on the trailer, it will sound like it's running normally, but could be running on only 2 or 3 cyls. Borrow/ rent a laser temp gun. Check the cyl head temps closely. Should idle between 145 and 155 degrees. A compression check if a really good test. Good to know just what the compression is every once in a while, for comparison purposes.

 

[dom_litty09]

Re: 1979 evinrude 140. running weird, idle dont seem right. any imput is appreciated

hey sorry i havent got on here in a while. but i ended up just dropping the boat off at the shop. the compression was under 100 in each cyl. i kinda ran outta ideas and didnt want to keep putting money into it if i didnt know what was wrong. also i dont wanna waste my whole summer on it again lol.. thanks for the advice tho. hopefully the shop does a good job n gets her going. if not i might be looking for an outboard 90-150hp

 

[emdsapmgr]

Re: 1979 evinrude 140. running weird, idle dont seem right. any imput is appreciated

Normal compression on that engine would be around 130+ for that year-with factory stock heads. That engine is significantly down on compression the way it is.