Engine bog 72 9.5 Johnson

[JasonF]

I have an engine bog that I cant seem to cure. The motor will idle fine but fall on its face when you gas it up real quick. When it first started doing this I could pull the choke a bit to clear it up, then it progressed to running it on full choke full time. Anyways last nite I cleaned the carb and put it back together thinking that there must be some gunk inside. The carb was pretty clean with a little tarnish but I cleaned it all anyways. It ran good in my barrel last night so I decided to take it for a test run today. I still have the bog when I take off but I can run full throttle now without the choke if I feather the throttle to full real slowly. Any suggestion?

Also, I have a dial for the lean to rich for low speeds, when the bog happens it seems to help if I turn it to more rich. Does anyone know how far this dial should be turned counterclockwise after tightening all the way to the lean side?

Thanks Jason

 

[ezeke]

Re: Engine bog 72 9.5 Johnson

The 1971 service manual [pg. 3-7] says turn it 3/4 counterclockwise after gently seating. I have six of the 9.5s and it never works that exactly.

I take it out 1 full turn and then adjust back in 1/8 increments until it coughs, then back it out 1/8. wait about 45 seconds between each adjustments so that the motor can catch up with the change.

It is real easy for the high speed jet to get fouled because it lies horizontally on the bottom of the float bowl behind the drain plug. It does not take much more than a little lint to mess it up.

BTW, make sure the screen on the fuel pump is clear and that the gasket between the pump and the motor is tight.

 

[JasonF]

Re: Engine bog 72 9.5 Johnson

The 1971 service manual [pg. 3-7] says turn it 3/4 counterclockwise after gently seating. I have six of the 9.5s and it never works that exactly.

I take it out 1 full turn and then adjust back in 1/8 increments until it coughs, then back it out 1/8. wait about 45 seconds between each adjustments so that the motor can catch up with the change.

It is real easy for the high speed jet to get fouled because it lies horizontally on the bottom of the float bowl behind the drain plug. It does not take much more than a little lint to mess it up.

BTW, make sure the screen on the fuel pump is clear and that the gasket between the pump and the motor is tight.

Thanks for the tips, are there any small parts when taking the fuel pump screen off that I should be aware of? It seems like a long time ago when I had it apart that there were some small parts that got kind of confusing when I had to put it back together.

 

[ezeke]

Re: Engine bog 72 9.5 Johnson

You don't need or want to take it apart at this point. Just take the cover off with the thumbscrew in the center. The screen is right there and it is either dirty or it is not.

If you should find yourself in such need for entertainment that you actually want to rebuild that pump, this web site might help you:

http://www.wisnersinc.com/Fishing Info/Rebuilding_fuelpump.htm