1966 Evinrude Lark starting problems

[sdilecce]

I have a 1966 Evinrude Lark 40hp that once started runs, and idles well. To start it though I need to squirt a bit of fuel in the carburator. If I do that it starts right up. If I don't it will not start, and choking it does not help. If the engine has been running and I shut it down, I can re start it by bringing it up tio half throttle, and then backing it to idle as soon as it starts. If it doesn't catch the first time though then it won't start untill I squirt gas in the carb again.

I'm thinking its a fuel pump issue, but the fuel pump and hoses look to be in excellent shape. I opened the fuel pump up and the diaphram looked ok.

I'm stumped. Can anybody help?

 

[Evinrude Boater]

Re: 1966 Evinrude Lark starting problems

Is the vent open on the fuel tank?

 

[sdilecce]

Re: 1966 Evinrude Lark starting problems

Yup, and once its running it runs great. I'm beginning to think I need to cleen out the carb.

 

[Kflc]

Re: 1966 Evinrude Lark starting problems

check the needle and seat in the carb, also check your idle circuit on the carb- your idle mixture may be too lean or galleries blocked- open up the mixture screw for this. Whether or not the fuel pump is bad, it should start up once you have primed the carb. Onother big one is the vacuum lines on the block-at the upper and lower maind and all the vacuum cut off switch hoses they are probably loose and crispy-just replace them with tight fitting fuel hose you may be losing crankcase vacuum in which case your fuel pump and carb will not process the fuel correctly on startup, ie, fuel mixture will not be drawn through the reed valves and the pump will not pulse from crankcase pressure. Check the vacuum situation first, the float and mixture parts next and the fuel pump last.

 

[Kflc]

Re: 1966 Evinrude Lark starting problems

check the needle and seat in the carb, also check your idle circuit on the carb- your idle mixture may be too lean or galleries blocked- open up the mixture screw for this. Whether or not the fuel pump is bad, it should start up once you have primed the carb. Onother big one is the vacuum lines on the block-at the upper and lower mains and all the vacuum cut off switch hoses they are probably loose and crispy-just replace them with tight fitting fuel hose you may be losing crankcase vacuum in which case your fuel pump and carb will not process the fuel correctly on startup, ie, fuel mixture will not be drawn through the reed valves and the pump will not pulse from crankcase pressure. Check the vacuum situation first, the float and mixture parts next and the fuel pump last. By the way, is that your motor in the avatar, I love those old evinrudes and Johnsons, I have a super sea horse 40 of the same vintage and a 33 horse too, both johnno's.