49 HP Force Smoking / Not Idling

[willawalla]

I have a 40 HP Force with a few problems. I'm not sure of the year but I assume it is one made by Chrysler since exhaust doesn't come out through the propeller.

The top cylinder gets plenty of spark but the spark plug is always wet and dirty after spinning it over or starting it. The bottom cylinder is completely fine. It will not idle smoothly for more than a few minutes after I get it started. But the motor will run off both cylinders. It also smokes continuously. Does it need a new head gasket I wonder, or it just a bad engine?

Thank you in advance for anybody who can help us out,
-William

 

[steelespike]

Re: 49 HP Force Smoking / Not Idling

You may need to adjust the idle mixture screw.To be right it needs to be done in gear warm.Idle speed is about 700 rpm.You can do in neutral on muffs but will need to be done on boat.Check compression.100 psi
within 10% cylinder to cylinder.

 

[willawalla]

Re: 49 HP Force Smoking / Not Idling

You may need to adjust the idle mixture screw.To be right it needs to be done in gear warm.Idle speed is about 700 rpm.You can do in neutral on muffs but will need to be done on boat.Check compression.100 psi
within 10% cylinder to cylinder.

Thank you for responding. I have been adjusting the idle mixture screw but I cannot find the right adjustment for that. And the idle speed never gets as low as 700 rpm. I was certainly wondering about a bad headgasket or warped head since it won't idle and it smokes excessively. Do you think that's possible? And a compression test was my next move, but I'll need to rent one. Will the compression be affected by problems with the headgasket?
Thanks again,
William

 

[steelespike]

Re: 49 HP Force Smoking / Not Idling

Has this motor ever run right for you?
Compression gauge can be purchased at Harbor Freight not expensive.
A bad head gasket might make white smoke sort of steam and can
cause poor compression.These motors do seem to smoke a lot in a barrel.
Does the smoke have that 2 stroke smell of burnt oil?
If the compression is uneven a couple of squirts of oil into the cylinder and check again.if a gasket compression won't change. a change usually indicates bad rings or rings stuck with carbon.
I would suspect you need a carb rebuild the motor may be flooding(smoke)
Also if the fuel pump diaphram is bad it can cause smoke and one plug to foul Don't know which one though.
Stick with the compression check for now.Then we'll go from there.

 

[willawalla]

Re: 49 HP Force Smoking / Not Idling

Has this motor ever run right for you?
Compression gauge can be purchased at Harbor Freight not expensive.
A bad head gasket might make white smoke sort of steam and can
cause poor compression.These motors do seem to smoke a lot in a barrel.
Does the smoke have that 2 stroke smell of burnt oil?
If the compression is uneven a couple of squirts of oil into the cylinder and check again.if a gasket compression won't change. a change usually indicates bad rings or rings stuck with carbon.
I would suspect you need a carb rebuild the motor may be flooding(smoke)
Also if the fuel pump diaphram is bad it can cause smoke and one plug to foul Don't know which one though.
Stick with the compression check for now.Then we'll go from there.

Thank you so much for replying.
I recently found out that it is flooding, but not through the carburetor. I disconnected the carb from the engine but left the hoses as they were and pumped gas into the engine. The gas will just flood through the exhaust. I suspect this means I will need a fuel pump diaphragm and gaskets. Unless there is anything else I don't know about? And no, the engine never ran since i bought the boat to fix up.
Thanks for all your help
-William