1962 Evinrude Sportwin running rough suddenly

[airman1094]

So I went to the lake today...took out my ole Jon boat with this 62 Sportwin. Fired up first pull. Ran great out to the other side of lake. I fished for 4hrs using trolling motor. Went to leave...checked primer bulb, started motor...ran ok for a few minutes then it started running rough...high and low throttle. It would seem to sputter and jerk...I'm guessing maybe failing plugs? Causing it to miss? I dunno what's y'all's thoughts!

 

[jimmbo]

Could be some dirt/varnish in the fuel system that came loose after being subjected to fresh Gas. Might be spark. A bit of Trouble shooting is in order. But first, do a compression test? Test to see if the spark will jump a 5/16" gap. What condition are the plugs in?

 

[racerone]

The plugs are fouling.----Put a new set in..------J4C

 

[F_R]

How old are the coils? Classic symptom of old original (cracked) coils. They all are cracked unless they have already been replaced.

 

[airman1094]

The coils were replaced a few years back to modern coils and new wires too. Fuel system was cleaned out including a carb refit. Plugs...I hate to say it haven't been changed since last year I think. Bought me some new ones today. If that don't solved it I'll pressure check...more to follow after I get the plugs pulled and swapped.

 

[fireman57]

Water in the fuel?

 

[Crosbyman]

why not start with the simple stuff assuming for now... electricals are ok with those new coils

sportwin… that is a 9.5 ? you said carb refit done…. when ??? it only takes a small piece of varnish crud as suggested by jimmbo


if so just unscrew the big bolt at the carb bottom behind it is an orifice plug (jet) at least blast some carb cleaner to dislodge any varnish crud

the low speed circuit is more tricky and requires the carb taken apart but lots of good utubes on this

https://www.bing.com/videos/search?...85CE088A90B6311F23EC85CE088A90B63&FORM=WRVORC

 

[racerone]

No, no----He said it is a 1962 model and that is a 10 HP.

 

[airman1094]

Fuel is good. Carb was literally just cleaned last week and rebuilt. Yep it's a 10 lol

 

[racerone]

Trouble shooting is required, no guessing.-------Is the thermostat installed and working properly , yes or no ?----Does spark jump a gap of 5/16", yes or no ?-----What are the compression numbers today ?----Have you inspected the diaphragm in the fuel pump , yes or no ?----Have you replaced the water pump impeller , yes or no ?

 

[airman1094]

Spark plugs replaced and now runs perfect with a small carb adjustment. Water pump is fine...just replaced, thermostat works...just monitored it's function today while running in a bucket....fuel pump is new. Didn't check compression but doesn't seem to need it. If it acts up again I will do more detailed troubleshooting.

 

[Crosbyman]

No, no----He said it is a 1962 model and that is a 10 HP.

you now what I had my 9622a in mind 9...62... 2a

well…. at least it is running...for now

 

[airman1094]

Right? It's always something....that's my luck.