1972 125hp evinrude running weired

[jonnymarquis]

hey guys, yet another problem i cant figure out. here is the problem and i ll try to tell everything its doing, i put new plugs in it this morning because i thought that was the problem i cranked it up at the house it ran fine just a little rough but cranked right up, then i took it out to the lake cranked it up at the dock it ran fine took it down the lake about a quarter mile then i had it just cruising at an idle for about 5 to 10 min. max. stopped it. went to crank it up about 5 min later. nothing!!! sounds like it has no spark or flooded, if i let it sit for a min or two, then crank it it will crank rev up then die out again all in a matter of seconds, with a lot of grayish blue smoke, then only if i let it sit some more will i get the same thing. i changed the plugs out on the water with new ones still the same thing. i took one plug out cranked it it ran rough like expected but it stayed running longer. put the plug back in it ran for about 5 min fine then started acting like it was flooding out again until it finally gave up and died. had to get pulled bake in. so any ideas about what may be wrong? the gas is only about 2 or 3 weeks old and i have used stable in it. i mix the fuel 50:1 like the book says. i have pulled the carbs off about 3 months ago and it has ran fine after, but this is just recently. the choke is open so don't think that is it. anyway sorry for the book but wanted to give as much info as possible. ty so much for the help.

 

[Solittle]

Re: 1972 125hp evinrude running weired

Is this one of a series of posts on this engine? If so it helps to keep them together so we have the history.

As to the above. What is the compression at each hole? Check for spark using a spark testor. You should get a bright blue snap that jumps a 1/4-3/8" gap.

When it dies have you squeezed the primer bulb? When you pulled the carbs 3 months ago did you rebuild them? Did the engine sit unused for a long period?

I suspect a fuel starvation issue.

 

[jonnymarquis]

Re: 1972 125hp evinrude running weired

well i have checked the pressure before but i think i did it wrong only got like 60 Lb but it was consistent with all 4 give or take a pound. the problem was i couldn't get the tester tight in the hole because it is recest. the spark tester i haven't tried but will soon. i have checked it against the block and they do have a good spark, IMO. yes the bulb is still pretty tight. i did pull the carbs let them soaked over night and did rebuild them with kits i bought on iboats.com. it did sit for about a year and a half. before i got it but that was why i pulled the carbs and cleaned them. i have a question it may be a dumb one but when i replaced the fuel line i put the bulb about a foot of line away from motor for easier access it was about a foot from tank when i bought it does it really matter where the bulb is? ty

 

[Lion hunter]

Re: 1972 125hp evinrude running weired

1st did you replace all the hoses from the motor to the carb, and clean the fuel pump? Now for troubleshooting.

1. Check compression and make sure you get a good reading without good compression your going anywhere. 60 psi is not good but I have never seen all 4 cyl drop equally like that so you probably got a bad reading.

2. Check for spark (also verify the routing of the plug wires).

3. If it has those and it's getting fuel (doesn't matter about the bulb as along as it the right direction) fire it up and let it get warm at idle. Once warm repeat those tests and see if anything changes.

 

[jonnymarquis]

Re: 1972 125hp evinrude running weired

i will try that as soon as i can raining like hell here now so probably wont get to do that today, any other suggestions for now?

 

[jonnymarquis]

Re: 1972 125hp evinrude running weired

friendly bump