20hp Johnson bogs down or dies

[mack]

" The problem that I'm hav

" The problem that I'm have is with a 20hp Johnson. It starts with one pull,idles good in neutral and in gear,has high rpms in neatral but, when rived in gear ether bogs or dies. Sometime when it bogs after a while it may go ahead and run normally. I've rebuilt carb, changed plugs,changed oil in lower unit,but, no help. I've notice some oil leaking from exhaust port into water, could lower unit be bogging engine or should I look else where. This is a points ignition.

Thanks for the help.
Mack "

 

[joereeves]

"Mack.... First check the comp

"Mack.... First check the compression which should be in the 100psi range and even on both cylinders. Then check the spark (with the s/plugs removed). The spark should jump a 1/4" gap on a magneto system, and a 7/16" gap on a powerpack equipped engine (you didn't state what year engine you have).

If the above are okay, I'd suspect that you may have overlooked a clogged high speed jet that's located near the center section of the float chamber, or the carburetor isn't adjusted or set up properly.

Joe

"