Bogging when cold?

[Toallhisdoom]

1986 Johnson GT 150
Model number is J150STLCDC

Motor revs fine when out of gear. Under load it bogs over 1/4 throttle until the engine warms up then it runs fine. Has trouble starting occasionally and will smoke excessivly.

Have tested spark. Passed.
Install fuel/water seperator.
Replaced both thermostats.
Added a can of seafoam in gas.
Fresh gas.

Is there a cold circuit in the carb? That would easily explain why it runs like crap when cold.

 

[ondarvr]

Clean the carbs.

 

[racerone]

Stop the " crank and hope " approach.----Do the compression test.---And there is no such thing as a cold circuit in these carburetors.

 

[ondarvr]

And you should keep it all in one thread, now it's split and people will have a tough time answering and knowing what's been tried.

 

[jimmbo]

1986 Johnson GT 150
Model number is J150STLCDC

Under load it bogs over 1/4 throttle until the engine warms up then it runs fine.


Is there a cold circuit in the carb? That would easily explain why it runs like crap when cold.

These engines do not have automatic chokes, they don't even have chokes. They do have a manually activated enrichment system to provide additional gas for cold starts and initial warm up.
A carbed engine will run less than fine until it reaches operating temp. Fuel doesn't stay vapourized well at cold temps. Starting a cold or cooled-down engine and expected full power performance without being at operating temp results in a high wear engine.