Idle Speed Adjustments

[walbert52]

I got my 1957 Evinrude 35 hp motor #25028-12064 running today I have 120 psi compression on both cylinders new coils, points, condensers wires and plugs. Carb was rebuilt and new fuel filter . Is started right up after a few tries run it awhile in a barrel and noticed that the water pump not pumping shut it off took the lower unit off and have a bad impeller with is now on order. I noticed the water tube and I took a small hose and clamped it to it then to my garden hose. I run very well but need to fine tune the carb, I tried to get it to idle down a little lower but could not the slow idle speed needle works ok but its just doesn't idle to low is there a idle screw on this motor. It's has a control box which is not hooked up at this time I have been using my hand on the thottle lever on side of the motor where the cable connects too. Please help me .

 

[F_R]

That lever you are using to hand-control the speed should have a nylon idle speed adjustment screw through it, with a spring on it. However they very often are broken off.

 

[Chinewalker]

Carb adjustments should be made with the motor on a boat, underway. Next to impossible to fine tune it in a barrel.

 

[oldboat1]

you flushed the motor with that hose hookup, or actually ran it that way?

 

[F_R]

What chinewalker said. Back pressure on the exhaust when on a boat on the lake will affect the idle, somewhat negating all your work adjusting it on a hose.

 

[walbert52]

Yes I did run it with the hose only for about 5 to 7 minutes but I then realized that it should be on the boat in the lake to tune it right, I also noticed the little plastic screw next to the lever I used to control speed and it is broken off with a little nub sticking out. I can I just remove the plastic and use a bolt of so sorts?

 

[oldboat1]

+1. And when you put in the new impeller, you don't want to test that operation with muffs either, as the water pressure from the hose partially takes the place of an operating water pump. Stick the lower unit in a barrel, check the operation of the new impeller, and get an initial setting for the carb needles, then readjust on the lake.

 

[walbert52]

Thank you guys for all your help, just one more question can I put a bolt in place of the plastic idle screw???

 

[F_R]

yes you can. But remember, the spring around it gave it some friction so it would stay where you put it. Maybe you can use a jam nut or something, if you don't have the spring. Maybe even some gasket cement. Anything so it doesn't spin around from vibration.

 

[oldboat1]

seen versions of that work OK. But you can look around and find the plastic screw too, if going for authenticity -- maybe spring too. On a couple of motors I have, the plastic screws are warped and hold their position that way. Guess that might have happened in use, or jiggered by PO.

 

[walbert52]

Thanks guy this is one GREAT SITE. Happy Boating