60 nissan runs rough until you run it at full throtle

[mr wisker]

my mid 80's nissan 60 will crank easy and idle fine until i give it throttle then it starts the hucka buck until i am able to run it wide open.once i run it wide open for a minute it will run fine.i can cut it off and sometimes i have to go back to wide open or it might run fine.

 

[pvanv]

Re: 60 nissan runs rough until you run it at full throtle

What do the plugs look like? When was the last time the motor was de-carboned? Is the fuel fresh? Have you verified every bit of the fuel system, from the tank pickup to the carbs? Is the compression good?

A small pinhole leak in the fuel system might allow air into the system. If that is caused by a weak o-ring in a connector, it might seal up when the vacuum comes up while running at WOT. If there is some debris floating around in the carb bowls, that stuff can slosh around -- and sometimes cause problems, other times not.

 

[mr wisker]

Re: 60 nissan runs rough until you run it at full throtle

What do the plugs look like? When was the last time the motor was de-carboned? Is the fuel fresh? Have you verified every bit of the fuel system, from the tank pickup to the carbs? Is the compression good?

A small pinhole leak in the fuel system might allow air into the system. If that is caused by a weak o-ring in a connector, it might seal up when the vacuum comes up while running at WOT. If there is some debris floating around in the carb bowls, that stuff can slosh around -- and sometimes cause problems, other times not.

i have checked fuel system from tank to fuel pump all good.fresh gas new plugs.never de-carboned the motor.is there an additive to put in fuel to de-carbon motor?someone suggested stator coil might be going bad.is there an easy way to check?never checked compression.thanks for reply.all help greatly appreciated.

 

[TOHATSU GURU]

Re: 60 nissan runs rough until you run it at full throtle

You need a service manual to get the values and procedures to check the ignition system...But, since the parts are no longer available it would probably be moot.

 

[mr wisker]

Re: 60 nissan runs rough until you run it at full throtle

You need a service manual to get the values and procedures to check the ignition system...But, since the parts are no longer available it would probably be moot.

thank you for info.i am going to go back through fuel system again.i will probaly get serious with it when it completely stops running.if i can not find part to fix it all i can say is that it was the best motor i have had.