This is a quote from Franz @ franzmarine.com about puddle drains on Chrysler, and I assume force as well outboards..
Puddle Drains
There is one maintenance issue that is overlooked by most Chrysler owner's because they are not aware of it: At idle, a motor does not burn all the fuel that goes into the cylinders and it "puddles" in the cylinder. This fuel has to get out of the cylinder or it will load up the engine and make it run rough and eventually make it not run at all. On the older motors this fuel was just dumped down the motor leg but it was more environmentally friendly (not to mention efficient) to recycle it so that this excess fuel went back into the motor. This system known as the puddle drain system has to have a one-way valve in it so as to pull the fuel from the cylinder at the proper time. This excess fuel that has been in the combustion chamber picks up contaminants such as small chunks of carbon. These contaminants have to be filtered out some way so that the one-way valves do not clog up so there are screens in front of the valves. All these contaminates build up over time and can clog the screens blocking the puddle drain system and leaving the excess fuel in the cylinders causing the motor to load up.
There is no set maintenance interval for cleaning these screens as many factors contribute to the formation of carbon which causes them to clog. Some of the factors include:
Using inferior oil in the gas
Using a prop with too much pitch so that the engine is lugging
Improper timing
Extended trolling time
Running without a thermostat or thermostat opening too soon.
The puddle drain covers are located on the starboard side of the block and usually extend over 2 cylinders (3 on a 3 cylinder). They are not hard to remove (except some 35-55 HP which have slotted screws in the lower part of the cover) but you will have to remove some other things to get to them. Suffice it to say, if you own a Chrysler outboard and the bolts have never been removed from the puddle drains, DO IT! If you are having trouble with your engine loading up, DO IT! Sometimes the screens can be cleaned but they may be coated with carbon making that difficult. You will need gaskets when you do this so just get new screens at the same time. They are about 65 cents and pop out with a knife or pick and the new ones are pressed in with your thumb. The whole job can be done for less than $10. on any motor and can make the difference between night and day. Now the disclaimer: It's possible you won't find anything in the screens but you will have the satisfaction of knowing that is not the problem. (LOL)
Franz
Puddle Drains
There is one maintenance issue that is overlooked by most Chrysler owner's because they are not aware of it: At idle, a motor does not burn all the fuel that goes into the cylinders and it "puddles" in the cylinder. This fuel has to get out of the cylinder or it will load up the engine and make it run rough and eventually make it not run at all. On the older motors this fuel was just dumped down the motor leg but it was more environmentally friendly (not to mention efficient) to recycle it so that this excess fuel went back into the motor. This system known as the puddle drain system has to have a one-way valve in it so as to pull the fuel from the cylinder at the proper time. This excess fuel that has been in the combustion chamber picks up contaminants such as small chunks of carbon. These contaminants have to be filtered out some way so that the one-way valves do not clog up so there are screens in front of the valves. All these contaminates build up over time and can clog the screens blocking the puddle drain system and leaving the excess fuel in the cylinders causing the motor to load up.
There is no set maintenance interval for cleaning these screens as many factors contribute to the formation of carbon which causes them to clog. Some of the factors include:
Using inferior oil in the gas
Using a prop with too much pitch so that the engine is lugging
Improper timing
Extended trolling time
Running without a thermostat or thermostat opening too soon.
The puddle drain covers are located on the starboard side of the block and usually extend over 2 cylinders (3 on a 3 cylinder). They are not hard to remove (except some 35-55 HP which have slotted screws in the lower part of the cover) but you will have to remove some other things to get to them. Suffice it to say, if you own a Chrysler outboard and the bolts have never been removed from the puddle drains, DO IT! If you are having trouble with your engine loading up, DO IT! Sometimes the screens can be cleaned but they may be coated with carbon making that difficult. You will need gaskets when you do this so just get new screens at the same time. They are about 65 cents and pop out with a knife or pick and the new ones are pressed in with your thumb. The whole job can be done for less than $10. on any motor and can make the difference between night and day. Now the disclaimer: It's possible you won't find anything in the screens but you will have the satisfaction of knowing that is not the problem. (LOL)
Franz