78' Evinrude 70 HP Running Horribly

Chokndog

Cadet
Joined
Nov 10, 2006
Messages
7
Guys,
MY 70 HP runs fine in the driveway with the flusher on it. But when I take it out it will hardly go into gear and when it does, it jerks into gear. It has also lost a lot of power and will only run full throttle at about half speed. It doesn't do it on dry land. I put carb kits in already. Please help.
Chokndog.
 

bgbass.1

Chief Petty Officer
Joined
Aug 1, 2007
Messages
558
Re: 78' Evinrude 70 HP Running Horribly

Drain lower end oil and see if you have metal chips
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: 78' Evinrude 70 HP Running Horribly

link and sinc, idle must be set in the water and in gear. you cannot properly set the idle on muffs in the driveway. when you did the carb kits, did you remove and soak all the parts, high and low speed jets, and blow out all orifices? have you check the compression all 3 cylinders?
 

Chokndog

Cadet
Joined
Nov 10, 2006
Messages
7
Re: 78' Evinrude 70 HP Running Horribly

I will drain the lower unit oil. I did soak the carbs, hi and low jets, blew the orifices. I have not checked the compression.
Chokdog
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: 78' Evinrude 70 HP Running Horribly

are you saying, that it will go into gear, and the engine revs up, but the boat doesn't go anywhere? that would be a spun prop, the prop has 2 metal hubs inner and outer, with a rubber bushing in between, these bushing will turn loose allowing the inner hub to spin at speed while the prop does not. it can be check by drawing a line across the hub, and giving it a try in the water.
 

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Chokndog

Cadet
Joined
Nov 10, 2006
Messages
7
Re: 78' Evinrude 70 HP Running Horribly

I changed the lower case lube. It needed changing, but no shavings! I removed the plugs and rolled the flywheel (don't have a gauge), and it felt like there was compression. I starts and idles fine. I have to slam the shifter forward to get it to jump into gear (and it does jump into gear) when its in the water. But It glides smoothly into gear in the driveway? Doesn't seem to be an issue in reverse in the water.
Chokndog
 

Chokndog

Cadet
Joined
Nov 10, 2006
Messages
7
Re: 78' Evinrude 70 HP Running Horribly

I think i got it figured out. The Throttle lever shoulder screw (which bolts the throttle lever and spark advance and shifter to the cylinder head) is stripped. There is a lot of play in the shifting/throttling mechanism. This could be casuing the inability to shift into gear under a load. What is the best way to fix this. Any ideas. Thanks.

Chokndog.
 
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