johnson 90 carburetor question

[flipper575]

Hello. I have jonson 90 -78 V4.<br />Im asking how the carbs are connected.<br />I start the motor and then take off the left side (watc behind) sparkcables. Motor runs at same speed (idle). Then i check is there spark. There is good spark.<br />Is it possible that upper carb is for right side cylinders an the lower for leftside.<br />Or how is possible that right side works and left not. <br />Can it been fuelpump that is broken. If i check the fuel pressure what it should be?<br />Have anybody replaced the orginal pump with automotive (electric) pump?<br /><br />Waiting for your help.<br />

 

[JB]

Re: johnson 90 carburetor question

Ahoy, Flipper. The upper Carb feeds the upper cylinders and the lower carb the lower cylinders.<br /><br />What is common to the right pair is one ignition system, a seperate system for the left pair.<br /><br />I suspect that an error or a prank has reversed the firing timing for the left pair. Verify that the spark plug wires are connected to the correct plug, then remove all spark plugs. With ignition ON, turn the flywheel gently until the top plug fires. stop and peer into the cylinder to see that the piston is very close to the top. Then check the other cylinder.<br /><br />If my vision is correct, the top plug will fire when the bottom cylinder is at top, and the reverse.<br /><br />Reverse the two orange wires to the coils for that side (unless you have already discovered that the plug wires had been connected to the incorrect plug).<br /><br />Please advise us what you find.<br /><br />Red sky at night, Sailor's delight. . .<br />JB

 

[Rex]

Re: johnson 90 carburetor question

RED SKY YOU ARE GOOD<br />REX A HUBBLE

 

[JB]

Re: johnson 90 carburetor question

Thanks, Rex. Your desire to help is noted and admirable.<br /><br />Red sky at night. . . <br />JB