1974 evinrude 70hp having wierd problem

[Cajun_catfish_hunter]

Hello, new to membership but been reading forums for about 2 years......

Any who, here's what i have :

1974 evinrude 70hp

It is running fine on start up and runs down the lake fine, no problems, UNTIL, you kill it then upon restarting it, and giving it the go-juice. When you try to throttle up in gear it boggs down tremendously, and dies, sometimes misses and spits and sputters but eventually dies. Its like its wanting to get up to speed but cant. Me and my g-paw took it out on the lake yesterday and done a little testing. Bubble is firm, has new coils (not my idea as i checked em for 1/2 in spark and they sparked fine) and gas is good checked it all. what we did find is when i held it right at the throttle possition it starts to bog down my g-paw manually choked the carbs one at a time.... top one made it bog down, middle made it bog down, but get this, when he choked the bottom it gained rpms enough to get up to speed, once up to speed it ran fine, its like it doesn't want to take the gas......

Compression is 135 across the board, and he put it in a mechanic;s shop and mechanic said he fixed it, but didn't take it out immediately, just took his word for it as he had good accreditation. Me personally i like to fix stuff myself, being i am a repairman by trade and a mechanic at heart, but i am stumped. Gonna pull bottom carb and check today but just wonderin if anyone may have any imput on this wierd problem. Oh btw if it kills you have to choke it and up idle on ctrler to get it to start..... sound fuel related to me but i need more opinions......... anything would be helpful.... thanks ahead of time

Sincerely
me

 

[Big Bubba]

Re: 1974 evinrude 70hp having wierd problem

Did the mechanic or you take and remove the carbs and give them a good cleaning. If those carbs have not been cleaned in a while I would clean them up and blow out all the passageways/jets.

 

[Cajun_catfish_hunter]

Re: 1974 evinrude 70hp having wierd problem

, thanks Big Bubba for the responce, and yes the mechanic supposedly cleaned the carbs and checked everything ellse out, about 500$ worth apparently, but thre again it still has the problem.......:facepalm:

 

[Daviet]

Re: 1974 evinrude 70hp having wierd problem

You could confirm that it is a carb problem by swapping the top and bottom carb, if the problem moves with the carb you have found your problem.
I would think that if you can choke one carb and it runs properly you still have a carb problem. If you paid to have the problem fixed, and it wasn't fixed, I would take it back and make them correct the problem.

 

[Cajun_catfish_hunter]

Re: 1974 evinrude 70hp having wierd problem

Ok here voes
Found problem.
Pulled the bottom carb apart and found it was missing the seal around the jet stem. Explanation.... when choked it would pull more of a convertion vaccume on the bowl and filled again with fuel and when let off it would use the fuel in the top of the panel owl and then start sucking air causing it to run lean as hell. I guess be forgot to put it back on...... remember a mechanic is only as good as thier worst helper. thank you for your responces.........

Sincerely?

 

[Cajun_catfish_hunter]

Re: 1974 evinrude 70hp having wierd problem

Please forgive typoes posted from a pos phone
Sincerly.... me