engine surge

[virgyWI]

Hello all hope some one can help, or give me a clue.Kohler courage pro 7000 series 24hr power twin. starts great. I do reg maintance. engine surging started so I changed air filter.no change
changed spark plugs-no change
changed fuel filter-no change
checked all hoses to be sure of no holes or loose hose-no change
sprayed carb cleaner in carb- no change
drained fuel and replaced with good clean gas-no change
running fast or slow it surges
after changin fuel it started to run better for 15sec then back to surging. also when cleaned carb same thing ran better for 15 to 20 sec then back to surging.dam thing is hard to work on because fuel pump is in outer plastic cover, so the cowling has to on before running.
Any ideas?
I have not taken carb off and cleaned it would need repair kit,
and do not want to order that if it is...fuel pump or ECI

 

[ILENGINE]

Does it smooth out with a partially closed choke. If so then you need to clean the carb.

 

[bertsmobile1]

Surging is fuel related 99% of the time.
Somewhere in the fuel system there is a blockage.
And don't forget the fuel cut off solenoid.

 

[virgyWI]

Does it smooth out with a partially closed choke. If so then you need to clean the carb.

No, black smoke all over and runs rough even a tiny bit choked.

now I am not familiar with this engine. But, I can take anything apart and put it together without too many extra parts left over. and it will work. so I may not know the name of the thingy you are taking about but with some good details of where to locate what I can figure it out.

 

[virgyWI]

Surging is fuel related 99% of the time.
Somewhere in the fuel system there is a blockage.
And don't forget the fuel cut off solenoid.

ok I believe that is located under the carb. right? how can I know if that is problem. tests?

 

[virgyWI]

ok I believe that is located under the carb. right? how can I know if that is problem. tests?

if I had schematic on this engine it sure would help