7.5hp poor idle

I have what i think is a 1976 merc 7.5 hp. I runs great at speed but has a lousy idle. with throttle off it will slowly peter out and die. if i catch it it will race then slowly peter out and die. I have adjusted the idle but can'tget it steady. ......i'm planning to rebuild the carb, it this the right place to start? Thanks!

Re: 7.5hp poor idle

Hi,
Well you need to start with a compression test.
Then move to the spark test. If you find out if you have good spark.
You should go to the fuel system starting at the tank make sure everything is clean and there is no restrictions in the fuel line or primer bulb and the disconnect. Then you need to check your fuel pump.or rebuild it parts are cheep
Last but not least the carb cleaning and rebuild.
I don't know how long the motor has sat unused, Hot weather will
evaporate the gas left in the carb bowl and leave a goo at the bottom of the carb.
I always run my motor until it stops to help with that high speed jets are at the bottom of the carb. Some on here will say you don't need fuel treatment,
I use it on every tank full, it works for me.


I hope you will let us know what you find

Hamit
BT1 USN ret

Re: 7.5hp poor idle

Hamit59 has good advice especially since we don't know more about the motor.
However, having had Mercs for the past four and half decades, they are not "idlers". If it were one of mine (which of course are well maintained and I am intimately familiar with), I would go directly to the carb rebuild. My 35 is doing the same thing - not quite as bad - but there is a freshly rebuilt carb on the work bench waiting for when she gets pulled for the season (along with a fresh charging circuit, impeller, etc.)

Re: 7.5hp poor idle

Be sure to clean the idle pickup tube.