60 hp 71 Evinrude -- Flooding

[malf]

My friend and I have been having some fun with a 1971 60hp Evinrude. The motor runs great for 20 minutes and then begins to spudder. It seems to be flooding and fouling the plugs. There were multiple problems when we first got the motor. The spark was weak and the battery was not charging. We replaced both the coil and the rectifier which fixed our ignition problems. We have tested compression and it is within spec and even across all three cylinders. We also ripped out the inboard fuel tank and are running a red can direct to the motor. The fuel bulb stays tight and we have no fuel leaks.

We were told that the carburetors were rebuilt before we purchased the motor. They seem to be in great condition and work perfectly. We believe now that the jets that were installed in the rebuilt carbs are two big. Since the motor cold starts without choke and runs for about 20 minutes and then spudders to an ultimate demise.

Are we way off base here? Can anyone tell me the spec jet size for a '71 60hp Evinrude? We took one out and it says "57" on the side.

The other idea that we had was that the thermostat was stuck open and the motor was being kept to cool. We have a heat gun and are going to test the temp next time we take one of our enduring 20 minutes rides.

We think we are very close to making this baby run great, we just need to little help in the home stretch. It has been fun either way.

Thanks!
Malf
Half owner of the "Mucho Sucko"

 

[freddyray21]

Re: 60 hp 71 Evinrude -- Flooding

seems like if the jets are too big it would load up and die quicker than 20 minutes. 20 minutes is a long time to run with a flooding carb. Is it possible it's overheating? Have you changed the impellar? Good flow out of the pee hole?

 

[tashasdaddy]

Re: 60 hp 71 Evinrude -- Flooding

are you getting a good spray out the exhaust relief holes, doen't have a pee tube. where did the motor come from? high elevation, or are you using in high elevation?

 

[malf]

Re: 60 hp 71 Evinrude -- Flooding

Thanks for the replys.

We have not changed the impeller but do have good flow out of the pee hole. It does not seem to be overheating, but we have never considered this option. We have tested the overheat alarm circuit and it does work but have not tested the actual temerature sesnor in the motor (do not know how to). We are not getting an overheat alarm.

This might be a stupid question, but is there an easy way to tell if the motor is overheating? When we pull the plugs out after it dies they are saturated with fuel. We are in Seattle and think the motor has been in this neck of the woods it whole life but I am not for sure.