Fuel Pump Dilemmas

[WHX?? 48,815]

So on a project here and always hesitant to get go juice flowing for the fear of where am I going to have gas spewing out somewhere. 

This time no different.

Only two things can happen now I either put the cigarette out or throw it on the whole thing and call the insurance company...

This time it was the fuel pump. ⛽️ 

K161 with a pulse pump. 

Turns out the mating halfs of the pump are so distorted that the original diaphragm was no way going to seal. Dried out and cracked after 50 years go figure.

A strait edge proved that. 

Filed down the halfs to what I thought was a good sealing surface... first pic. 

No dice and replaced the diaphragm with a after market. 

Next try is to put the halfs on the head glass but hold no hope for this. 

Problem I believe is the aftermarket diaphragms are not thick enough to seal. 

2nd pic notice the difference.

OEM has two sealing gaskets one with the circle cut out for proper diaphragm pulse.

Root of the problem is warpage of the halfs between the screws.  

[Achto 27,570]

Putting sand paper on a piece of glass and planning the surfaces won't do the trick?

[ebinmaine 67,455]

6 hours ago, Achto said:

Putting sand paper on a piece of glass and planning the surfaces won't do the trick?

Yeah 👍. 

 

I've only had to do one pulse pump so far but it was badly warped. 

Hand planing solved it. 

 

 

[ranger 1,750]

If you can remove any springs, valves, etc from the housings, put the housings in a vise, (separately), with the diaphragm surface against a flat plate. Apply enough pressure to level that surface against the plate, then ‘Warm’ the housing gently with a heat gun or gas torch, and leave it to cool down. This usually removes most of the distortion, allowing you to finish off lapping surfaces flat on a sheet of wet or dry paper, (without having to remove too much material to level the surface), then do as @Achto suggests. One further thing regarding gaskets, etc, thicker gaskets, (especially rubber), can worsen leaks, due to allowing distortion to occur in between fasteners, (rubber does not compress, but distorts easily, and ‘extrudes’ out under the fastener positions), particularly if over tightened!

Doug.

[Pullstart 62,840]

Sometimes when you’re riding Uncle Jim’s tractors, you gotta give ‘em mouth to mouth…

 

 

[SylvanLakeWH 25,547]

7 minutes ago, Pullstart said:

Sometimes when you’re riding Uncle Jim’s tractors, you gotta give ‘em mouth to mouth…

 

 

 

 

The @ebinmaine school of fuelology...

 

 

[ebinmaine 67,455]

2 minutes ago, SylvanLakeWH said:

 

 

The @ebinmaine school of fuelology...

 

 

 

 

YESSUH !!!! 

[WHX?? 48,815]

2 hours ago, ranger said:

particularly if over tightened!

Doug.

Guilty as charged Doug.

Going to try the above suggestions... thanks. 

[rmaynard 15,436]

I have rebuilt a few pulse pumps. Only a few have needed to be resurfaced. I use Brian's (buckrancher) diaphragms. However, the one on my K161 that I recently rebuilt had problems with leaking, even with a new diaphragm and surface planing. So I put a little bit of yellow Teflon thread sealer on both surfaces. It worked. 

[JoeM 7,873]

53 minutes ago, Pullstart said:

you gotta give ‘em mouth to mouth

No that is mouth to snout!

A snout is the protruding portion of an animal's face, consisting of its nose, mouth, and jaw.

The wet furless surface around the nostril is the fuel pump!

And in Uncle Jim's case the "wet furless suface" is warped! 

[peter lena 8,620]

@WHX?? https://www.walmart.com/ip/CarBole-12V-Universal-Electric-Fuel-Pump-2-3-5PSI-Low-Pressure-Micro-42S-28-GPH/972444636  have 2 of these on , my horses now , after swapping out a bad pump with a new diaphram pump I had , that  also had  went south with little use . these car bole pumps are very quiet / solid , low pressure , good price . also added a single LED  dash light on my first electric pump , to verify its working . hook up to run on ignition switch , monotors itself . also added a fuel check valve , line is always visibily full of fuel . probably swap over my last horse as well . dash light is single green bulb . anything I suggest has been in use and reliably  works . gassy pete 

[squonk 41,079]

Had the same issue years ago. Aftermarket diaphragm was too stiff to work correctly. Had to get one from Brian.

[WHX?? 48,815]

32 minutes ago, squonk said:

Had to get one from Brian.

That's where mine come from. More on order. 

Thanks for the post Greasy but electric would be NA for a 701 resto. Something just wouldn't be right about that...

Make matters worst the sentimental bowl Dan INSTISTED  I use does not shut off 100%. 

Edited June 2, 2023 by WHX??

[squonk 41,079]

All you need is a little "Nascar Ingenuity" and hide an electric. I know I know. Gotta have it Original so you hafta tinker with it all the time! 

 

I got stuff "hidden on my 1467 Special.  One of them will loosen tooth fillings! 

[ranger 1,750]

Possibly an easier solution could be, Roughening of the surfaces between the screw holes, the generous application of 24hr ‘JB Weld’, allow to cure, then lap the faces with wet or dry paper on a surface plate or equivalent.

Doug

[Racinbob 11,063]

5 hours ago, WHX?? said:

That's where mine come from. More on order. 

Thanks for the post Greasy but electric would be NA for a 701 resto. Something just wouldn't be right about that...

Make matters worst the sentimental bowl Dan INSTISTED  I use does not shut off 100%. 

 

 

Jim, do you need another pulse pump for the body? I have one off my 854 that I won't be using. 

[WHX?? 48,815]

33 minutes ago, Racinbob said:

 

Jim, do you need another pulse pump for the body? I have one off my 854 that I won't be using. 

I do not Bob

I have a spare that Dan hid in the shop somewhere. I found it but the good news is glassing it did he trick and it sealed up nice. 

 

Still no fire in the hole tho. Starter generator has got issues. Stalls on compression stroke. 

Just downloaded the SG manual from @pfrederi and will be seeing if can be saved.

[squonk 41,079]

5 minutes ago, WHX?? said:

 

 

Still no fire in the hole tho. Starter generator has got issues. Stalls on compression stroke. 

Just downloaded the SG manual from @pfrederi and will be seeing if can be saved.

Clean all the paint you slathered on the block where that genny mounts and on the mount too. When I built my engine run stand I reduced voltage drop by a volt just by cleaning dirt, paint and rust off the surfaces and bolts. Small blocks draw 60-80 amps on initial rotation.

Edited June 2, 2023 by squonk

[JoeM 7,873]

1 hour ago, ranger said:

the generous application of 24hr ‘JB Weld

I have had great success with MotoSeal

Permatex MotoSeal Gasket Maker Grey was designed for two and four cycle engines Ideal to use on motorcycle case halves and carburetor gaskets. It forms a solvent based, tough, flexible bond within 20 minutes. This unique Gasket Maker forms a tough flexible bond that is highly effective on irregular or uneven joint surfaces.

[WHX?? 48,815]

4 hours ago, squonk said:

Clean all the paint 

Been there done that. 

Suspect bad armature but I don't have the test equipment to verify it.  Going to a pro shop that can do everything I can't.  

https://www.fondyautoelectric.com/

Funny you should mention that stuff @JoeM. I did use a smidge of it for insurance. Mine does not say motoseal tho? 

I got it for a 5hp Briggs where the tank is right on the bottom of the carb. Didn’t work ... other underlying issues tho.

Edited June 2, 2023 by WHX??