Fuel Pump

[mr.pipes 4]

I am having some fuel related problems with one of my horsies.

I can't find any info about the output of a kohler mechanical fuel pump.

What kind of flow should I expect from a disconnected fuel line while cranking the engine?

It's a M20 if it matters

[rmaynard 14,922]

The pump does not have to have a lot of pressure or volume, only enough to keep the carburetor bowl filled. With the hose disconnected, you should see a reasonable flow while cranking the engine. The pressure is only about 2 lbs.

While holding the ignition switch in the start position (with the plug wire disconnected), and with the line from the pump pointing straight out, with every revolution of the engine, my K241S pulses a stream about 4" to 6" long before it drops off.

[mr.pipes 4]

Thanks for the reply Bob!

I didn't have that volume from mine but it seems that it's providing enough fuel. Still sorting some issues out at the moment.

When I was trying to find info on how much flow elsewhere I didn't have much luck. I read a post on another tractor forum where someone stated it should spit the gas out about two to three feet. That seemed a bit much to me considering the mechanics of the pump. I still wasn't sure if there was a problem with mine because I was only seeing what I thought was a pathetic little dribble when cranking the engine. Then I saw a video on YouTube where the guy had a M20V with a vacuum pulse type fuel pump and he demonstrated the flow when cranking the engine. The flow in his video is slightly more than I had. I'd say it was a steady flow but if the line was held horizontally I don't think you would get any distance from it.

I am aware this video shows a vacuum pump and not a mechanical pump but the fuel requirements of the engines are the similar.

If anyone is bored and wants to see, it happens at around 6:20-6:30.

Here is the link and a quote from the video description.

"If fuel flows from the vacuum fuel pump, than the pump is working. Kohler does not provide a more precise way of checking the vacuum fuel pump, and they say if you get fuel flowing through the pump when the engine is turned over, than the fuel pump is working correctly. Kohler does say the vacuum fuel pump should pump a minimum of 2 gallons of fuel per hour with a pressure at 0.3 psi and a fuel lift of 24 in, but they do not give you a method to check these specifications."

[wheelhorse656 20]

Thanks for the reply Bob!

I didn't have that volume from mine but it seems that it's providing enough fuel. Still sorting some issues out at the moment.

When I was trying to find info on how much flow elsewhere I didn't have much luck. I read a post on another tractor forum where someone stated it should spit the gas out about two to three feet. That seemed a bit much to me considering the mechanics of the pump. I still wasn't sure if there was a problem with mine because I was only seeing what I thought was a pathetic little dribble when cranking the engine. Then I saw a video on YouTube where the guy had a M20V with a vacuum pulse type fuel pump and he demonstrated the flow when cranking the engine. The flow in his video is slightly more than I had. I'd say it was a steady flow but if the line was held horizontally I don't think you would get any distance from it.

I am aware this video shows a vacuum pump and not a mechanical pump but the fuel requirements of the engines are the similar.

If anyone is bored and wants to see, it happens at around 6:20-6:30.

Here is the link and a quote from the video description.

"If fuel flows from the vacuum fuel pump, than the pump is working. Kohler does not provide a more precise way of checking the vacuum fuel pump, and they say if you get fuel flowing through the pump when the engine is turned over, than the fuel pump is working correctly. Kohler does say the vacuum fuel pump should pump a minimum of 2 gallons of fuel per hour with a pressure at 0.3 psi and a fuel lift of 24 in, but they do not give you a method to check these specifications."

another good way to check a fuel pump to see if it is good is to put fuel line on both ends stick the end that pulles the fuel from the tank into a small container with fuel in it hold the pump about 14 to 16 inches above the container. if you pump the arm 6 times fuel should be comeing out the other end altough the pump should prime its self by 5 pumps. when pumping do it fast like this 1,2,3,4,5

Instead of going slow like 1....,2....,3.....,4.....,5. I got that info out of my small engine repair manul. Hope this helps!