how do you adjust a motor with no carb adjustments

[trucker28]

I have a 1964 18 hp johnson that I just got running but it is running real rough but the carb has no adjustments on it and i dont know any other way to make it run better the only thing on carb is a rich and lean knob but I have no idea what it is for. can anyone help me make it run better

 

[F_R]

Re: how to adjust a motor with no carb adjustments

Re: how to adjust a motor with no carb adjustments

Of course it has an adjustment. The rich and lean knob is the adjustment. It only is effective at idle speeds. The high speed is a fixed jet and is not adjustable, nor does it need to be.

Consider the possibility that the rough running is not a carburetor problem at all.

 

[ondarvr]

Re: how to adjust a motor with no carb adjustments

Re: how to adjust a motor with no carb adjustments

...

 

[tx1961whaler]

Re: how to adjust a motor with no carb adjustments

Re: how to adjust a motor with no carb adjustments

What had been done to the motor so far? What is the history of the motor? Every bit of info helps to figure out what is wrong with it. I check things in this order:
Compression test. Cylinders should be with 10 percent of each other
Spark test with a spark tester
Change the impeller if I don't know how old it is.
Change the gear oil.
THEN, I mess with the carb or fuel pump, since by then I know that I have good spark, good compression, and it won't overheat while I'm messin with it.

 

[trucker28]

Re: how to adjust a motor with no carb adjustments

Re: how to adjust a motor with no carb adjustments

What had been done to the motor so far? What is the history of the motor? Every bit of info helps to figure out what is wrong with it. I check things in this order:
Compression test. Cylinders should be with 10 percent of each other
Spark test with a spark tester
Change the impeller if I don't know how old it is.
Change the gear oil.
THEN, I mess with the carb or fuel pump, since by then I know that I have good spark, good compression, and it won't overheat while I'm messin with it.

hey thanks for the help I just bought the motor was not running when I got it I replaced the points and condensser, pulled the carb and cleaned it and the Compression test was 95psi on both and spark test was not done but I have plenty of spark now which I did not have before.the water pump was not changed yet I did not think that would make a differance on how it runs but I planned on getting one. and the gear oil how do I change it thanks again

 

[tashasdaddy]

Re: how to adjust a motor with no carb adjustments

Re: how to adjust a motor with no carb adjustments

did you remove the high speed jet, and use a rebuild kit, on the carb? did you replace fuel lines with alcohol resistant lines? Read the TOP SECRET file.

 

[tx1961whaler]

Re: how do you adjust a motor with no carb adjustments

To change the gear oil, remove the two slotted drain screws (one drain, one vent) DON"T take out the phillips head screw. That is for the shifter. Drain the old oil out, and refill form the bottom hole until it squirts out of the top hole.

 

[trucker28]

Re: how do you adjust a motor with no carb adjustments

To change the gear oil, remove the two slotted drain screws (one drain, one vent) DON"T take out the phillips head screw. That is for the shifter. Drain the old oil out, and refill form the bottom hole until it squirts out of the top hole.

Thanks that must be the two screws way down by the prop that are about 4 inches from each other. I need to change the water pump is'nt the waterpump down there cause if it is I should change that first you think.