check valve ?

[John c 79]

314-8, after it's sat for a long period of time, it takes a lot of crank time to get fuel back to the carb, and get it cranked

 

the longer it has sat, the longer it takes, there's no other fuel related issues with the machine, is this normal for a kolher single ? Would a check valve in the fuel line be a solution, has anybody here experienced this on their machine or tried to fix it  

 

thanks

 

John 

[ebinmaine 67,566]

On the rear tank models such as yours the fuel pump has a fair amount of work to do.  

 

Get a marine primer bulb and

Replace ALL your fuel line front to rear. 

 

Before start just squeeze the bulb a couple times and voila!!

 

Faster starts.  

[John c 79]

that sounds easy enough, you say replace the entire length of the line, I did that recently, any reason why I couldn't install a primer bulb in the line ? 

[ebinmaine 67,566]

1 minute ago, John c said:

that sounds easy enough, you say replace the entire length of the line, I did that recently, any reason why I couldn't install a primer bulb in the line ? 

 

IIFF you use ethanol free gas and IIFF the new line is less than maybe 6 months old you MIGHT be alright.  

I've seen Ethanol gas begin dissolving rubber fuel hose in 4 or 5 months. 

 

It would be a great idea to install a new fuel filter between the tank and primer bulb. 

 

Unfortunately with the usage of alcoholic gas, replacing the fuel line has now become a periodic maintenance item like filters and spark plugs.  

 

[peter lena 8,633]

@John c agree with @ebinmaine  above on the fuel line replacement , would also ad  a fuel filter in the  frame / seat area , and another  closer to engine ,  have these  fuel check valves in my horses ,https://www.amazon.com/EVIL-ENERGY-Return-Petrol-Aluminium/dp/B07ZB42CGT?th=1  , perfect spot is the  short vertical hose from  fuel pump to carb , like it was made for it .  also use STA BIL  gas treatment in all my fuels , with no carb issues . install check valve vertically , arrow facing  up to carb, you will always have a  fuel charge waiting . only my experience , and use .  this is a  good  improvement point , pete

[lynnmor 7,307]

Major brands of fuel line are resistant to ethanol.  I have four tractors that are 25 to 31 years old, I replaced the fuel line once on two of them and always used ethanol laced gas.  I would like to install the primer bulbs but I would like to find short ones that aren't cheap junk.

Edited October 30, 2022 by lynnmor

[ri702bill 8,327]

@John c Your Kohler engine has a mechanical fuel pump that has 2 "check discs" with springs - one for fuel inlet, one for fuel outlet. Over time, they can get dirty to a point where they do not really close. That  creates a hard start condition for 2 reasons - it allows fuel in the line to drain back to the tank and if the outlet valve is open, and second, the pump draws fuel at a reduced rate. Not something a miracle "Mechanic in a Can" fuel cleaner will fix - if it is the original pump, probably time for a cleaning and a rebuild kit... Been there, done that.....

Bill

[oliver2-44 9,757]

Sometime you can just disassemble and clean the pump.  google" Lowell at Wheelhorse Parts and More has parts for some fuel pumps and  Then and Now Automotive also has parts for some (not all) mechanical pumps. Send them a picture of your pump.

 The pumps have 2 little small disc check valves with tiny springs under a plate that is screwed on inside.  I remove that plate holding the pump part in a 1 gallon baggie to catch the top spring that loves to fly away sometimes.  

[ri702bill 8,327]

28 minutes ago, oliver2-44 said:

Sometime you can just disassemble and clean the pump.  google" Lowell at Wheelhorse Parts and More has parts for some fuel pumps and  Then and Now Automotive also has parts for some (not all) mechanical pumps. Send them a picture of your pump.

 The pumps have 2 little small disc check valves with tiny springs under a plate that is screwed on inside.  I remove that plate holding the pump part in a 1 gallon baggie to catch the top spring that loves to fly away sometimes.  

Fly away sometimes??? Never had one stay put!! - I guess it gets excited to see daylight again after all those years in hiding......

[squonk 41,140]

I tried 2 of those in line check valves. didn't work worth a 

 

[Horse Newbie 7,071]

I noticed hard starts on my 1994 520H(20 hp Onan), added a primer bulb at the suggestion of a few on here, and it cured the hard start problem.

After that I put a primer bulb on my 1984 Work Horse GT-1600(16hp Twin Briggs).

I did that when I reassembled the Work Horse, so I don’t really know if I needed it or not.

I can easily still get non-ethanol fuel so that’s what I use. I also use Sta-bil  in my small engines, and it hasn’t seemed to hurt, even though I don’t really know if it helps. All I can say is I have had no fuel related issues since I started non-ethanol and Sta-bil regiment.

I do not use a check valve in the fuel line.

[Ed Kennell 38,201]

1 hour ago, squonk said:

I tried 2 of those in line check valves. didn't work worth a 

 

 

 

Try turning them around with the arrow pointing towards the carb Mike.     

[squonk 41,140]

8 minutes ago, Ed Kennell said:

 

 

Try turning them around with the arrow pointing towards the carb Mike.     

Don't work!   I even tried moving the arrow from the left to the right!

[kpinnc 12,079]

On 10/30/2022 at 8:34 AM, ebinmaine said:

Get a marine primer bulb and

Replace ALL your fuel line front to rear. 

 

Agreed. This has saved more external charging and battery life than ever for me. Outstanding mod!

[Horse Newbie 7,071]

5 hours ago, kpinnc said:

 

Agreed. This has saved more external charging and battery life than ever for me. Outstanding mod!

A primer bulb would have a check valve… correct ? Because they only prime in one direction…

[clueless 3,002]

Lift up your seat turn off the fuel cut about 3 or 4 inches off the fuel line install the marine pump bulb with the arrow pointing towards the carb tighten the two clamps zip tie it to the seat pan bracket turn the fuel back on give it 3 or 4 squeezes fire it up. Like I've said here before best thing I ever did to my rear tank WH's for under $15.00. If it sits for 3 or 4 weeks or 8 months lift the seat 3 to 5 pumps and the thing will fire right up .

Edited November 1, 2022 by clueless

[lynnmor 7,307]

25 minutes ago, Horse Newbie said:

A primer bulb would have a check valve… correct ? Because they only prime in one direction…

They actually have one at each end.

 

[Ed Kennell 38,201]

25 minutes ago, Horse Newbie said:

A primer bulb would have a check valve

 

Actually two check valves.     Same as all fuel pumps.

[kpinnc 12,079]

5 hours ago, Horse Newbie said:

A primer bulb would have a check valve… correct ? Because they only prime in one direction…

 

Yep. 

 

Can't believe I'm gonna say this, but...

 

Just squeeze until they firm up and you're ready to go. 

[RED-Z06 2,221]

It really shouldn't be a problem, my 314-8 with the magnum and mechanical pump can sit weeks, and kick off on 2 or 3 revolutions.  The carb should have fuel in it, and the pumo should have fuel in it, if the pump has drained back the line should still have fuel in it just from gravity...for at least 2 or 3 months.

 

Onans are a bit different with the fuel system up high, they can take a few more spins after a month off.

 

Make sure your pump and carb arent seeping fuel

[kpinnc 12,079]

45 minutes ago, RED-Z06 said:

It really shouldn't be a problem, my 314-8 with the magnum and mechanical pump can sit weeks, and kick off on 2 or 3 revolutions. 

 

There's alot of places to develop a small air leak and quite a long fuel line to the fuel tank under the seat. Fuel in the sediment bowl evaporates over a couple weeks.

 

The kohler fuel pump seems to be the worst culprit. As the diaphragm dries out over time, they just let a little air in. A tractor used once a week may not see the issue much. Much longer than that, all of mine drain back. A pulse pump takes dozens of revolutions to fill the bowl back up. I'd rather prime with a bulb and save wear and tear on my batteries and starters.

[peter lena 8,633]

@Johnc  have this car bole electric pump now  a few years ,  very quiet and reliable , have that on my c- 85  , 12  horse magnum ,  also added a  single LED  green light on the dash  to show its  operation . only a suggestion, pete 

 

[RED-Z06 2,221]

9 hours ago, kpinnc said:

 

There's alot of places to develop a small air leak and quite a long fuel line to the fuel tank under the seat. Fuel in the sediment bowl evaporates over a couple weeks.

 

The kohler fuel pump seems to be the worst culprit. As the diaphragm dries out over time, they just let a little air in. A tractor used once a week may not see the issue much. Much longer than that, all of mine drain back. A pulse pump takes dozens of revolutions to fill the bowl back up. I'd rather prime with a bulb and save wear and tear on my batteries and starters.

Just going by what my personal experience has been, if a Kohler is leaking back in 2 weeks there's definitely an underlying problem...here is a video i made just now, this tractor is soley used to push dirt and the last i used it was a good month ago after i got crushed asphalt dumped.  Its not cold this morning...55ish degrees but this is how it always starts...chinese carb and Chinese pump included.

 

 

[Ed Kennell 38,201]

Just another observation on these under the seat fuel tanks.    If you keep the fuel tank over 1/2 full, the mechanical fuel pump on the Kohlers is low enough that they will not lose their prime.      Of course it doesn't work with the higher mounted pulse pumps.        My experience has been only about 25% of the fuel pumps are drop tight and never drain back and lose prime over time.

          

[ebinmaine 67,566]

6 minutes ago, Ed Kennell said:

Just another observation on these under the seat fuel tanks.    If you keep the fuel tank over 1/2 full, the mechanical fuel pump on the Kohlers is low enough that they will not lose their prime.      Of course it doesn't work with the higher mounted pulse pumps.        My experience has been only about 25% of the fuel pumps are drop tight and never drain back and lose prime over time.

          

 

 

I've even had issues with losing prime on my 74 c160 which of course has the tank up high.

If it didn't get used for a few weeks or I ran it out of fuel... It was interesting.