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1968 evinrude 85hp lack of rpm high idle

S

stan goff

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"I got engine and because of i

"I got engine and because of it sitting for years unused I got carb kits and rebuilt carbs. got new fuel pump on engine and replaced. new fuel tanks, rubber lines, bubble pump, and fittings. checked and cleaned dist. rotor and set points to what was writen on cap. replaced plugs. Did compresion test came out good. Went to dealer got recomended oem prop for size of boat. The engine runs smooth and clean but the rpms stop increasing @ half throttle, the butterflys are opening all the way"
 
"well,..i would do a search,on

"well,..i would do a search,on here,which there is some valuable info,on those old dawgs......if u could somehow,get into the 80;s,.eng wise,...u would be sooo much better off...."
 
"Check to see that you have th

"Check to see that you have the recommended fuel line size. Is the squeeze ball arrow pointing to the engine? Check the fuel filter. Could be one on the pump. Check to see if it's over propped. Check that the timing is advancing as it should. Use insulated pliers to carefully pull the spark plug wires off one at a time while running at idle to see if it still runs the same. If it runs worse that's a good thing. If it doesn't change it's not working on that cyl. It's very hard to tell if they are all running properly by ear without doing this. If they aren't then check the CARB on the affected cyl. There are some very hard to see ports in them. Look at them very carefully. You can tell by looking at the casting outside where most of the ports run. check them all out. I used 3 copper threads, twisted together, out of a 16 guage wire to work through all the ports. There are two little holes hiding right where the base of the metering rod goes into the body that go up at a 45 degree angle that are hard to see. They're hidden on the sides of the casting. Those caused me problems with my #3 carb which was where most of the green slop was. Hope this helps."
 
"Oh, and make sure you've

"Oh, and make sure you've got the fuel mixed properly. If there's any doubt burn what U have in your tractor and mix fresh for the boat."
 
"In installing the carburetors

"In installing the carburetors back onto the engine, it's possible that you have the linkages between the carburetors out of adjustment.

The linkages shound be set so that the throttle butterflies (and choke butterflies) open and close at the same time, and that the throttle butterflies are indeed closed at idle.

Let us know what you find."
 
All along I thought that the 6

All along I thought that the 68-85Hp only had one carburetor.So post a model # so we know what motor is the subject matter here.I have one of those motors in a box for parts.
 
"ikia.... You are correct. I g

"ikia.... You are correct. I got ahead of myself apparently. The 1968 85hp has but one dual barrel downdraft carburetor. It was right around there that they went to the dual carburetors and I didn't check.

Chalk it up to age, early hours, and a faulty home air conditioner that's being worked on as I now type. The mind went elsewhere.

That high idle may be that the scribe mark on the cam is not aligned where it should be..... dead center with the throttle roller when the throttle butterflies start to open."
 
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