Printable View
Low rpm, in or out of gear. If it’s in gear when it coughs and the rpm is low enough, it will stall. I am leaning towards a carb adjust being off a little but I haven’t tried anything yet. ‘74 Evinrude 15 hp. She runs out good at a blistering 14mph wot. Good enough for my needs for now so I’d like to get it smoothed out, and thanks for any help in advance.
That thing is as old as I am. I don't stutter, I do cough occasionally, but I do an awful lot of grumbling. :biggrin
May need a good carb cleaning
If it has a pulse fuel pump it could be a little bit weak
I am thinking with the sputtering and coughing the timing is a little off. Is the timing cam follower adjustable or fixed linkage? It has been some time since I have worked on an older OMC. I am guessing the 74 is still points. Somewhere right in there is when they went electronic ignition. If it is not electronic ignition I would say points and timing. Post up some pictures of under the hood of the carb and timing cam follower and I might be of some help. I love the old 60's and 70's Evinrudes and Johnson's. Points and cond, carb kit, 2 new coils and plugs and wires used to cost me less than $100 for parts and in a afternoon I could usually make a motor run if it had compression add in a water pump and it was good to go and you should not have to worry.
Thanks Flint, I’ll try to get pics this afternoon. Motor is in pretty good shape and runs good, the cough is the only issue I have.
Have you tried Vicks NyQuil ?? :Rofl
It isn't the same as what they had in the 70's. They took all the good stuff out.Quote:
Originally Posted by wannabe fisherman
Was it a sudden onset, or start out small and gradually got worse?
:Rofl:donoQuote:
Originally Posted by DockShootinJack
I have a 72 6 hp Fisherman model Evinrude i bought new.
It still purrs like a kitten, i use it on a 68 12’ Grumman i bought from a friend the same year.
Its just a bit too tipsy for my liking where im sharing the water with those big Gators however. lol
Let me explain why I think it’s carb. It will idle fine for 3 to 5 seconds and then cough once, the rpm falling. I’m wondering if it isn’t a bit lean and when it runs out of fuel it coughs and while still spinning the fuel is gathered enough to continue to run, and the process repeats.
Yo, I had one of those 15 or so years ago and sold it when I bought my stick steer boat. It was always good to me, and this one will also be good once I get it squared away.
Sounds lean to me too.
I would pull and clean plugs for a baseline, then get to adjusting the carb(s). Sounds like a classic case of lean.
At the carb(s), screw the mixture screw all the way in to seated counting turns carefully as you go. Back out to the recommendation (Usually 1 round or a round and a half) and fire it up. Better to be a quarter to a half turn out to the rich than to be on the lean side.
If it doesn't smooth out, inspect fuel lines and fuel filter (Strainer). Follow up with a serving of Seafoam. Best wishes!
Rebuild the carb.
Check for a new old stock one as well. I searchrd for a rebuild kit for a chipper vac carburetor. $75. Found a new old stock carburetor shipped to my door $22. Always worth a lookQuote:
Originally Posted by Barnacle Bill
Keep us posted on what you figure out.
Probably be the weekend when I get into it unless I get off early one day, thanks for all the input everyone.
I can be pretty dumb sometimes. I’ve been noticing this cough for a couple of weeks or so and thought I had to remove stuff in front of the carb to get to the adjust screws. So I got off a little early today, got a water tank set up, removed the cover and cranked it up. Knowing it had to warm up some, I raised the idle some and started looking things over as I started to loosen the breather screws. Wondering how much had to come off I looked at the front of the motor. Staring me in the face is the slow speed adjustment knob. I turned it a quarter turn to the rich and it never stuttered once in the 10 minutes or so it ran before impending rain ran me inside. Thanks for all the input, I’ll try to do better next time.
Great, glad to hear it sounds like it is running right.
I wish I had a nickel for every minute I spent in the garage looking for a wrench that was in the right hip pocket of my jeans.Quote:
Originally Posted by skeetbum
They say it gets worse!
Fer sure !!!!Quote:
Originally Posted by TheGrandPoohBah
Reminds me of when my Brother and I were just kids we went fishing with my Dad and Granddaddy. We left out from the boat launch down the river in a small vee bottom boat with the 1957 model 18 HP Evinrude Fastwin that my Brother still has today. Dad had the throttle turned as far as it would go. A few minutes later, Granddaddy spun around and told Dad, "Son, wind it on up and get us on a good plane". Dad said "I have it wide open, it's all it will do". That didn't sit well with Granddaddy. He got up, stepped over us, and told Dad "Trade seats with me for a while". Granddaddy left it wide open and turned the High Speed Knob a little, and that boat wound up into skint back mode, fast and smooth. In a little bit He let it idle down, and adjusted the Low Speed Knob a little till that motor idled like a sewing machine. Then Granddaddy stood up and told Dad, "OK Son, you can have your seat back now".
Ever since, we have always said that motor NEVER ran as good as it did when Granddaddy took a hold to it.
In all honesty, that was probably because me and my Brother wanted to be like Granddaddy, and would twist those knobs every which a way, without a clue as to what we were doing - we just wanted to be like Granddaddy!
True story!!
I like an easy fix
Poohbah, my first Evinrude was a ‘56 18hp that took both hands to pull start. Had it on a few boats but the 12’ Shakespeare wonder craft was the most fun. Don’t know how fast it was but we used to outrun 50hp trihull bow riders that were everywhere back then. Pressure tank for fuel if I remember right, gave $180 for it. Some good memories you dragged up mentioning that motor. It would fly with one person in it.