Chrysler 99 not running right

[jim]

" I have a Chysler 9.9 (no

" I have a Chysler 9.9 (not sure what year...model 92HA, serial #3680) that runs briefly when the top
engine cover is put on. It will bog down for a minute or so then run back up to full speed. It will continue to do this over and over. However, with the top engine cover off it purrs like a kitten. I have replaced the spark plugs and cleaned/rebuilt the carb but it still acts this way. It also seems to be smoking alot compared to other outbord motors I have seen. I use the 50:1 fuel/oil mixture as recommend by the maintenance manual, but it seems like it maybe to much. Any help would be appreciated, it is driving me crazy!!! "

 

[joereeves]

"Jim.... Chrysler engines are

"Jim.... Chrysler engines are not my line of expertise but your problem would pertain to any outboard engine. It could be caused by possibly one of two things (or however unlikely...both).

1 - There has to be a passageway area on either the hood or the lower hood pan that would allow air to be drawn in to the carburetor. If someone closed that off for any reason, it would cause the carburetor to draw less air... and excessive fuel. However if this problem existed, I would think that the engine would simply load up with fuel, slow down and die out.

2 - You may have a faulty gasket or seal somewhere that is allowing the engine exhaust to enter the powerhead area. With the hood off, the carburetor is drawing fresh air directly from the surrounding area (which is vast). But with the hood on, the air supply source is cut down drastically, resulting in the carburetor drawing in the exhaust which results in an improper mixture. The high speed draws in a great amount of exhaust slowing the engine down. At a slow speed that mixture changes allowing the engine to rev up.... and the cycle continues.

There are other reasons why a engine would have the problem you describe (up and down rpms) such as leaking fuel fittings, etc but in your case (having the hood affect the engine) #2 is the most likely cause.

Joe

"

 

[scott]

" I have a Montgomery Wards Se

" I have a Montgomery Wards Sea King that was made by Chrysler, it was doing the same thing today. Check your choke. My carb has a funny two part spring loaded choke valve, for some reason the front half of it was getting sucked up into the closed position when the cowling was on, thus making the mixture richer and slowing the motor down. It seems as if the spring that hold it in the open position needs to be a little more stout. Don't know why it doesn't do it with the cover off, but that's what I was able to figure out. "