fuel problem

[bkarp@roadrunner.com 5]

After running my m12-s kohler engine for about 50 min. it stops running, has spark but nothing  coming out of fuel pump.  Replaced pump still have  same problem.  Also replaced mag,fuel lines , filter, gas cap.  Does anyone what else could be the problem. Thanks for any help.

[Ed Kennell 35,904]

Do you have a good supply of fuel to the pump?

[gwest_ca-(File Mod) 10,509]

Did you check the filter in the tank? It is part of the fuel valve.

What can happen is debris in the fuel will get sucked up to the screen and eventually block it off. When not running it will float away only to come back after the next run period.

One way to check is to have at least a half tank of fuel. Pull the fuel hose off near the front and see if gravity will completely drain the tank uninterrupted.

[peter lena 8,087]

@bkarp@roadrunner.com  those tank valves are cheap $ 6-7 , use some synthetic grease for instalation , not a lot , but it makes the gromet connection much easier , I  also have 2 fuel filters on my horses , large one close to tank , small one closer to carb. would also drop the carb bowl , probably full of fuel hose debtis , cood time to replace that with a clear vinyl, fuel rated hose ,  this is part of  a typical fuel starvation problem ,  pete

[pfrederi 17,165]

1 hour ago, peter lena said:

@bkarp@roadrunner.com  those tank valves are cheap $ 6-7 , use some synthetic grease for instalation , not a lot , but it makes the gromet connection much easier , I  also have 2 fuel filters on my horses , large one close to tank , small one closer to carb. would also drop the carb bowl , probably full of fuel hose debtis , cood time to replace that with a clear vinyl, fuel rated hose ,  this is part of  a typical fuel starvation problem ,  pete

 

 

I would have to disagree with the clear line.  I have used both yellow and blue...after a couple years they shrink and get very stiff

[bkarp@roadrunner.com 5]

thanks guys for the help,i put anew shut-off valve and cleaned tank still have same problem, might think of putting electric pump on unit

[peter lena 8,087]

@pfrederi  agree with the stiffining  of the clear line , but  at least it does not break down like the rubber does . that led me onto planning running a steel line the length of the frame , in the inside frame angle area , held in place , extend  maybe a foot at each end for a swage lock fuel line / filter set up . that would eliminate line break down issues . as the weather hopefully gets cooler , already have the coiled steel tubing . as it is though , my  STA BIL fuel additive  has made for , zero debris in my carbs , filters are always clean ..always top off the tank and add  it to constantly keep that in the fuel set up . its also cheaper than 6$ gas . pete

[Gasaholic 183]

9 minutes ago, bkarp@roadrunner.com said:

thanks guys for the help,i put anew shut-off valve and cleaned tank still have same problem, might think of putting electric pump on unit

Does the problem happen while gas cap is off? If not, (remove gas cap when problem happens and see if it continues) you may have a plugged gas cap vent, thus vapor locking things.  Other things I have seen is with older braided fuel lines as OEM, the inner portion of the hose can get holes in it and as fuel pressure gets in it can balloon and plug off the hose internally (Much like plaque build-up in your arteries cause heart attacks)   I'd run it til it happens and then pop fuel line off fuel pump at inlet side and see if you have fuel flow, if you have good flow there, you may have a ballooning problem in the hose between pump and carburetor. Better yet, good braided fuel hose is fairly cheap in 25 foot rolls on ebay/amazon, I'd just buy a box of that and replace all fuel lines from tank to carb, and be done with it. Then if you still have the fuel flow problem, I'd pop the pump apart and check if it may have had check valves popping loose - They have been known to do that on the plastic body pumps (and the aluminum body pumps too) - We'd often just put the check valves back in and then use a center punch to stake them in place.