1968 evinrude 55 hp

[imported_tweeter]

Motor was rewired for conventional ignition years ago i.e. car coil, condenser, and no amplifier, ran great for a long time. Now it runs great until fully warmed up. After about 15 minutes of running the engine starts to miss and run really rough. I just replaced the coil, and all the wiring under the shroud as it was really "crusty", points are mirror smooth and gapped to .011. The car coil has an internal resister but doesn't seem to cause any problems, i.e. the motor starts pronto. Could this be a carb/fuel issue or am I better off looking further into the electrical end of things. Also what is a good number for compression on this engine? Any advice would be most helpful. Thanks, Tweeter

 

[DJ]

Re: 1968 evinrude 55 hp

The fact that it runs good for 15 minutes leads to electrical. Since it is not stock, can't help there.

It is possible that you are getting junk in the carbs after that amount of running.

Clean the tank(s) and clean the carbs, that will, at least, eliminate that.

By the way, does the fuel primer bulb go flat, when it acts up? If so, your tank is not venting-fuel starvation.

Compression should be over 100 psi/cyl. and be within 10 psi of each other.

 

[imported_tweeter]

Re: 1968 evinrude 55 hp

The fact that it runs good for 15 minutes leads to electrical. Since it is not stock, can't help there.

It is possible that you are getting junk in the carbs after that amount of running.

Clean the tank(s) and clean the carbs, that will, at least, eliminate that.

By the way, does the fuel primer bulb go flat, when it acts up? If so, your tank is not venting-fuel starvation.

Compression should be over 100 psi/cyl. and be within 10 psi of each other.

 

[imported_tweeter]

Re: 1968 evinrude 55 hp

What's a good way to clean the carbs? Should the compression be checked cold or hot?