1978 Evinrude 115hp

[jseperfect]

I have a 1978 Evinrude 115hp motor. It runs great but I noticed that when I push the throttle all the way down, it only opens the butterflies on the carb about 30%. I can manually grab linkagae and open it all the way. Is this normal? Would it be ok to adjust the linkage so I can get full throttle or will that cause other problems?

 

[racerone]

The throttle butterflies should be horizontal at full throttle.-----Look for something broken / missing / stuck on the linkages.--------This would not go out of " adjustment " for any reason other than something broken or missing.

 

[jseperfect]

The throttle butterflies should be horizontal at full throttle.-----Look for something broken / missing / stuck on the linkages.--------This would not go out of " adjustment " for any reason other than something broken or missing.

So should I adjust the screw out further? Its intentionally screwed down now. However if I open it up all the way it will open the butterflies more at idle.

 

[jseperfect]

Are you talking the carb butterflys inside or the choke butterfly outside. Do you have a book so you can time and sync the engine it could be it is just out of sync if it is the choke maybe it is just a spring not correct to pull the butterfly all the way open.

The carb butterflies. There is the bracket tha moves as you push the throttle down, that bracket hits against the rod that opens the carb, when throttle fully pushed down the carb still only opens about 30%. There is an adjustment screw but if I move it forward then it will open the butterflies more at idle. maybe I should make a video.

 

[papyson]

i forget exactly how this mechanism looks but there is a roller inside a slot that advances timing....the roller is built with a steel bearing and the a fibre outside on it..this fibre will break and fall off and timing will not advance all the way...dont remember if this affects carbs too...

 

[jseperfect]

I guess I should say that the motor is running fine and I don't think anything is broken. I get good top speed even with 30% open on the butterflies. I was more wondering if I could get a little more by adjusting the threaded screw.

 

[racerone]

One threaded screw ( with black rubber button ) is the maximum ignition advance and it should not be adjusted.--------Time to post pictures to see what the problem is !!

 

[jseperfect]

Here is a link to a video i made of what I am working with. If you need other pictures or videos let me know. The guy at the boat shop said it should engage fully and that I could be losing 5-7mph when it doesnt, but I dont wnat to pay 100hr if I dont have to, to have him fix it.

http://www.youtube.com/watch?v=lSfALvcsq0w&feature=youtu.be

 

[racerone]

Looked at half your video.----------How can you check whether butterflies are fully open or not by having the cover in front of the carburetor???--------Take it off and visually look to see where they are at full throttle.----------Like I said before this stuff is well made and just does " not go out of adjustment "

 

[jseperfect]

Looked at half your video.----------How can you check whether butterflies are fully open or not by having the cover in front of the carburetor???--------Take it off and visually look to see where they are at full throttle.----------Like I said before this stuff is well made and just does " not go out of adjustment "

I had it off before and watched it only open about 30%.

 

[jseperfect]

http://www.marineengine.com/parts/johnson-evinrude-parts.php?year=1978&hp=115&model=115899C&manufacturer=Evinrude§ion=Carburetor Is there a roller on the throttle lever item 25 follower roller it looks like it is missing to me.

There is a little black rubber tip on it but maybe it is missing that piece. My brother made the comment that if it was larger that it would open slightly faster an dprobably reach 100% open. I will look and make sure.