1984 EV 70HP carb/plug question

JohnWI

Seaman
Joined
Sep 14, 2011
Messages
73
I'm not sure if I'm having only one or a multitude of issues. In order to get on the water, I need to go upstream through cruddy/weedy water. As soon as I was beyond the SNW zone, I throttled up. I'm fairly sure I was weeded up and cavitating: I had very little power to make it onto plane and was shooting a heck of a V shaped water wave on to the transom. After few seconds, it "gave way" and we were off as usual.

About an hour later, I thought the engine was running fine at speed but when going slow, the motor was exhibiting some roughness. Then when inching along in another SNW zone, it was killing. I had to use the fast idle throttle and she'd start, but when backing off and trying to shift into gear she'd kill again (unless I was really snappy and got into some throttle before killing).

Today, I pulled the cowling and noticed an unreasonable amount of gas in the bottom case. (more later) I pulled the plugs and checked the compression, around 122 in each, pretty close. But I did notice that the top plug was pretty dry compared to the other two.

So my first question on this issue is whether or not it's fairly common that the upper carb takes a little longer to get charged with fuel?

I did see that the silencer gasket was not fully intact on the lower edge so that's where I was losing some fuel (oh please let that be all). But my next question is how much gas is lost out of the throat of the carbs that gets "recycled?" Is it only from being tilted or???

Any other words of wisdom? I'm kind of guessing that my idle jet on that top cyl must be gunked up. Ran normal (approx 33 mph on my 16' Aluminum SuperSport) until the slow areas when it got rough or killed.
 

James R

Commander
Joined
Feb 1, 2007
Messages
2,679
Re: 1984 EV 70HP carb/plug question

Your top cylinder is not getting fuel and is most likely the cause of your running problems. Time to remove, strip and clean the carbs. Do a proper job and use new kits. If a cylinder is not getting fuel it is not getting oil and you will blow your motor. I soak all parts in Gunk Carb and parts cleaner. Wash out with water and blow clean with compressed air.I also use my Ultrasonic cleaning tank as a second op and wash and dry again. Gunk ap should be sufficient if you soak and poke.
 

Big Bubba

Senior Chief Petty Officer
Joined
Apr 11, 2007
Messages
746
Re: 1984 EV 70HP carb/plug question

I agree with James R with using the Gunk Carb and parts cleaner in the gallon paint container that Advance Auto Parts or the others sale. That is the best stuff to use and it comes with a basket inside. If you do the soaking, removing all the plastic and rubber pieces and take it out and blow through each jet, passageway with a spray can with the red straw of Carb Cleaner then blow out with compressed air it should run really good for you. That is what I would do.
 
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