Potential fuel pump upgrade

[bds1984 1,435]

So the story goes...  My C175 is experiencing what I think is a fuel delivery issue.  After running her for ten minutes the engines spits and sputters before shutting off.  I go to restart and no luck.  But if I squeeze the primer bulb a few times she'll fire right up like there is no tomorrow and we're back along the way.  I am suspecting the fuel pump is weak.  I have never looked at the fuel pump and I do know that original Kohler units are difficult to come by for a reasonable price.  I have a fuel pump that is the newer style that runs off crankcase vacuum from an M18 I am willing to try out after some light fabricating.  Has anyone here ever made the swap?  

[pfrederi 17,741]

 Just install an electric pump. 

[lynnmor 7,308]

Is the gas cap vented?  Try running it with the cap loose.

[pabird 40]

I recently had the same problem. Exact same symptoms and squeezing the priming bulb as it was sputtering corrected the problem. I checked the fuel cap, and replaced the fuel filter. No change. So I changed the fuel pump as it was a cheap 15 dollar mechanical replacement. Same problem!! Ok now it has to be the squeeze bulb that I installed last season. So I removed it and checked its operation and it seemed to be fine but I didnt reinstall it. Problem solved. Runs perfectly now. I bought a rubber cork to fit the gas tank and hooked it to the bulb with a piece of hose and use it to prime the carb when the tractor sits for extended periods.

[bds1984 1,435]

2 hours ago, pabird said:

I recently had the same problem. Exact same symptoms and squeezing the priming bulb as it was sputtering corrected the problem. I checked the fuel cap, and replaced the fuel filter. No change. So I changed the fuel pump as it was a cheap 15 dollar mechanical replacement. Same problem!! Ok now it has to be the squeeze bulb that I installed last season. So I removed it and checked its operation and it seemed to be fine but I didnt reinstall it. Problem solved. Runs perfectly now. I bought a rubber cork to fit the gas tank and hooked it to the bulb with a piece of hose and use it to prime the carb when the tractor sits for extended periods.

I performed all of that, with new fuel line and gas tank gauge/cap, except replacing the pump.  I have used these primer bulbs on many tractors over the years with zero issue.  I guess the next time I am out in the garage I will remove the primer and run it for a while.  

[oliver2-44 9,761]

I’m a fan of the Facet electric pumps. However if you want to rebuild the original metal one you can get a kit at “Then and Now Automotive. Their website is down but Google their name to get their phone number. It’s best to talk to them anyway with old pump in hand to insure you get the right kit

Edited April 30, 2021 by oliver2-44

[bds1984 1,435]

Well after removing the primer bulb, I am still experiencing the same issues.  After running the tractor for a couple hours over the weekend it died four times but was able to restart it by pressurizing the tank with a bike tire pump.  What I find peculiar is the fuel filter had fuel in it each time the engine died.  The next step will be to rebuild the fuel pump.  If that doesn't work, I'll go the electric pump route.  

[pfrederi 17,741]

The price of a quality fuel pump kit with shipping is close to a good electric.  I wouldn't waste my time..  Under seat tank tractors with fuel issues get facet posiflo pumps.....

[midpack 866]

I read about KT17's having cam lobe wear that affected fuel pump actuation.

I put electric on mine years ago for under $30 with pump, relay and fuse

[bds1984 1,435]

The electric fuel pump showed up today so I installed it under the seat.  Installation was a snap and the machine started up with zero issue and no need for the choke.  However... the pump is making my voltage gauge flutter between 12-14 volts!  The pump is on a 4 amp fuse with 16 gauge wire so a high pulse of current is not to blame.  This is the pump I purchased.  Has anyone else experienced this issue with an electric pump?  I bypassed the whole wiring system by connecting the pump right to the battery and the gauge still flutters.  I like how the pump operates so far, but I don't think I can live with it killing gauges like this.  Any thoughts?


 

[Tuneup 1,433]

I guess that's the most significant load on that tractor. Your wiring through the regulator should be checked to ensure it's clean and not frayed. If that's fine, the regulator may be on its last legs.

[squonk 41,155]

There is not a lot of charging current on these tractors. Pretty normal for a pump to effect the gauge. The gauges even leave a lot to be desired. 

[seuadr 488]

looks like that pump pulls 1.2 amps at 12v.  i dunno what typical usage is without the pump for that motor, so i can't say if that is a "problem" but it looks like most of the K and KT series kohlers are typically either 15 or 30 amps. 

[bds1984 1,435]

I understand there not being much for a charging circuit, however, the pump draws 1.2-1.4 amps, the charging system is 15 amps, and the gauge is not some cheapie one either.  As far as other current draw, the only item is the ignition coil.  Fluttering back and forth five-six times a second doesn't seem normal to me.  

[pfrederi 17,741]

Haven't had any issues with the Facet posiflo pumps I use...

[bds1984 1,435]

After mowing yesterday and running the tractor for an hour, I did not have the stalling issue I experienced before.  The electric pump has taken care of that issue, however, I am not a fan of it driving my voltage gauge crazy.  

 

On another note, has anyone ever installed a vacuum pulse fuel pump on a K or Magnum series engine that previously had a mechanical pump?  If so, where did you tap into the engine for the vacuum/pulse?  In the past I have been tempted to braze/solder a 1/4" hose barb onto one of the valve covers of my KTs/Magnum Twins so I could utilize a vacuum pump.  Any thoughts?

[Bill D 1,926]

On 5/2/2021 at 9:23 PM, bds1984 said:

After mowing yesterday and running the tractor for an hour, I did not have the stalling issue I experienced before.  The electric pump has taken care of that issue, however, I am not a fan of it driving my voltage gauge crazy.  

 

On another note, has anyone ever installed a vacuum pulse fuel pump on a K or Magnum series engine that previously had a mechanical pump?  If so, where did you tap into the engine for the vacuum/pulse?  In the past I have been tempted to braze/solder a 1/4" hose barb onto one of the valve covers of my KTs/Magnum Twins so I could utilize a vacuum pump.  Any thoughts?

I have been making these plates to use vacuum pumps on the K/M series.  I've done it on two different M12 engines and it works great.  No need to solder a pipe on the valve cover of your KT 17.  Simply remove the old pump and make a small plate to cover the opening.  If the old pump gasket stays intact and stuck to the block, you won't even need to make a gasket.   Buy a 1/8" pipe tap and tap a hole in the center of the plate for a barbed fitting.  The plate I made is made of stainless steel.  No painting required.  Use any good quality vacuum pump.  Pumps used on Briggs and Kawasaki engines work well.   As a side note, use a longer hose between the engine and the pulse port on the pump to prevent oil from coming out of the breather on the pump.   Bill

[Bill D 1,926]

Another picture.  Pump is a Kawasaki pump.  Longer hose between the engine and pulse port on the pump prevented oil from coming out if the breather port in the pump, the brass colored disc in the picture.  Bill

[bds1984 1,435]

On 5/6/2021 at 2:18 PM, Bill D said:

I have been making these plates to use vacuum pumps on the K/M series.  I've done it on two different M12 engines and it works great.  No need to solder a pipe on the valve cover of your KT 17.  Simply remove the old pump and make a small plate to cover the opening.  If the old pump gasket stays intact and stuck to the block, you won't even need to make a gasket.   Buy a 1/8" pipe tap and tap a hole in the center of the plate for a barbed fitting.  The plate I made is made of stainless steel.  No painting required.  Use any good quality vacuum pump.  Pumps used on Briggs and Kawasaki engines work well.   As a side note, use a longer hose between the engine and the pulse port on the pump to prevent oil from coming out of the breather on the pump.   Bill

Thanks Bill.  I am working on this setup as we speak.  Well, waiting on the tap to get here.  Prime has turned into 3-4 days for many items for me now.  I made a plate from 1/4" steel earlier today and have the hose barb, just not the tap.  What I cannot quite figure out is what port in fuel in and which is out.  There are no markings at all but shouldn't be too difficult to figure out.

Edited May 10, 2021 by bds1984

[Bill D 1,926]

There are small arrows cast into the inlet and outlet.  They are hard to see but they are there.  The pulse line is on top of the pump, inlet on the right, outlet on the left.  Bill

[theoldwizard2 2]

On 5/6/2021 at 5:34 PM, Bill D said:

There are small arrows cast into the inlet and outlet.  They are hard to see but they are there.  The pulse line is on top of the pump, inlet on the right, outlet on the left.  Bill

Correct !  The metalic colored hole on the topic is thevent for the pulse line.

 

This pump is common on some B&S engines.  The original design/manufacturer is Mikuni.  Prices range from about $15 - $50, so shop wisely !

[bds1984 1,435]

I'm well aware of there being arrows on pumps.  The M18 on my 520 has a vacuum pump I installed many years ago has arrows but the pumps that just arrived do not so it looks like I'll be experimenting.  I guess that is what happens when a guy tries to save a few dollars...

[bds1984 1,435]

Well, I took a gamble with the vacuum fuel pump installation and fuel flows correctly given their being no indication of flow.  So now I am off to mow in the nearly 90-degree heat today.  After rebuilding the center spindle and replacing the idler pulley on the deck, cutting the grass is SO much quieter.

[peter lena 8,634]

@bds1984, my input would be since I increased  my overall grounding , any electrical issues I had are gone , think the best one was the left rear corner of engine to frame , with serated washers , and a 4 ga cable wire to the battery flat ground rail next to battery , pto lever runs under it. also dielectric grease its bolt down . mine is a facet pump , and my amps are solid . also detailed all electrical connections , pete  

[peter lena 8,634]

@bds1984, first picture is the ground rail , for cable mount from engine corner , 5th picture shoes the cable ground from engine corner to ground rail . first picture also shoes , pto lever washer addition , removes sloppy play .  no more bouncing amp gauge , pete