what a fantastic, simple, straight-forward explanation. Thank you.

Excellent video. This is the first time I have seen one of these taken apart and explained. Great job. Thanks for the info and video.

Awesome man! It takes one guy who is willing to be a good man and help out with a video like this!! Thanks!!!

Best explanation of how it works I've ever het,,period !!!! Thank you

I have had fuel get into the crankcase, that has always been a big mystery as to how in the hell that happened! Thanks for clearing that up.

Fantastic. This video helped me understand the just how urgent the small leak at my fuel pump vent really is.

Thank you simple and too the point just what I needed

Great Job! This guy explains every detail well.... even the Name type.....and consequences.... shares his knowledge well! Thank You

Very nice. Thanks for making this!

Thanks for sharing that, very good to know! 👍👍

I really appreciate you taking the time to make this video

Yet another great explanation. Well put 👏 MM1

Very good explanation.

Hey, Jeremy! Thanks for this one! I had a Tecumseh pump that didn’t seem to be working on a Tecumseh v-twin engine. It took long crank times to get the engine to fire. I took the pump apart and found fine debris inside but close inspection showed no damage to diaphragms or check valves. Cleaned it up good including ultrasonic, sprayed with a bit of fuel on all surfaces, reassembled and started to mount back on the engine but found the last 1/4 inch of fuel line to the carbs was cracked so I cut that off and completed connecting. Full choke, full throttle, key on and she fired after one crank revolution! Stopped and restarted multiple times cold and then hot with no further issues so I have to believe it was a small leak in the hose causing the problem.

Great explanation, well spoken

Nice tutorial! Thanks for the info.

Yep, those fuel pumps can be little buggers. They are hit or miss as some last less than a year and some can last over forty years like the one on my 1969 Wheel Horse. Thanks for the info! 👍

Fantastic advice.

RIGHT TO THE POINT, NO BS BLAH BLAH HEAD TALKING !!

Thank you. Well explained.

Thank you! This is an excellent video. I wish more of those who give DIY instructables break down the mechanical operation and theory of operation as defined as you. There is much more clarity and understanding to what this mechanism is supposed to do but also instructs as to why something (the broke part or replaced part) maybe doing other things.

Thanks for the video, I did not realize that they built rebuildables fuel pumps.

Great video, thanks for sharing!

You are super smart man thank you so much for your video

Great video Thank you

Great video friend ThankYou!

Thank you! Great video

Very good video. Thank you

Very informative mowermedic1. 👏🏻👍🏻

Thanks for the video!

Great video!

Just bought a mower I’m seeing fuel pouring out of that vent thing, the thing will run but soon as I give it load it stalls out, thank you!

Excellently detailed video and explanation - liked and subscribed FOR SURE! A question: Do the Mikuni pump mounting bolt holes match the cheap plastic bolt holes? Hose lengths or orientation are not a problem - my 2 Kawi-V engines' plastic fuel pumps may be big-time problems in the future though...

God bless you AMEN

Great video thank you. Can you tell me if it matters whether the tank is above or below the pump - so either the pump is sucking the fuel out of the tank or the fuel flows by gravity (as well as suction) to the pump. Based on how it works, it doesn’t look like it would matter, but you would know better than me. Thanks

great explanation. I just purchased a similar fuel pump for my skidoo except that outlet with the bend at 90 degrees positioned on its side is pointing up on the new pump I purchased. Supplier says its similar to my OEM. The problem is that it wont fit in its original location with that outlet pointing up. Can it be rotated without damaging it.

“Mikuni makes nice stuff!”.. Great share! Larry

Thank you for this video I have a generator and it is brand new and the crank case filled with gas and I thought this is what it was but didn't think it could have been because it is new. Does the pulse come from a crank case that is filled with oil? Or from the intake? I am going to take the bad one apart and see if the diaphragm is broken. 😊

I was wondering if you can bypass pump gravity feed on a walk behind mower

Can you link me to a rebuild kit for those? The Briggs parts site only shows a plastic replacement for the entire pump. All I need is the interior diaphram and such.

My cart Yamaha g16 I believe gas want pull fuel from tank. If I prime it it will run poorly until it loses its prime again. Carb and pump are a few years old. They seem to still be ok. Should I replace my fuel lines or tank pickup? Thanks for your help

What do I do if if I got gas leaking out of that circular tan part on the very top? It’s a brand new pump but it’s a black one same style tho?

Use vacuum from the intake. No issues

I have Mikuni fuel pumps on my Rotax 582 and Rotax 503 engines, both with dual Bing 54 Carburetors that specify fuel pressure from 3-6psi. Wondering what the capability of the Mikuni fuel pumps are? These are pulse pumps with short pulse lines. The pumps are mounted near the engines and the fuel lift is about 3ft. What are the fuel pressure specifications for these pumps under your "standard conditions"? I plan to install fuel pressure gauges to monitor fuel pressure, and am wondering what "normal" pressure should be? Thanks for any help!

Where does that pulse line connect to crankcase? 2009 Hisun 700 Big Muddy. Fuel issue and pulse line broken. Where does it connect too? Replaced pump and even auxillary tank, same issue

Put 2 of them together and you have a mechanical heart :)

I'm having a weak pump after replacement maybe a bad vacuum from engine? New lines and clamps

My 1998 ez go will start for about 30 seconds then not again until a few hours later . I replaced the fuel pump , carburetor, plugs , solenoid .. still same issue .. i only use ethanol free gas

My original fuel pump is mounted inside fuel tank, and I bought dellorto P34 pump as replacement. Can I submerge it in fuel and mount the same way?

I have a 2019 Scag 48" walkbehind, SWZT48-541FS, Kawasaki FS541V. Pull-cord. I open the choke. When I try to start it, it will NOT start. However, if I add 1 teaspoon of fuel into carburetor, it fires/starts. After engine has been running a short while, it will restart withOUT adding fuel directly into the carburetor. I have been doing this for 1-year. Why does it need to be manually primed to start? Is the fuel-pump, Kawasaki 49040-7008 Fuel Pump, likely the problem or more likely the fuel line or something else? BTW, I have changed the fuel filter and I had an ultrasonic cleaning of the carburetor. Those did not help the issue. Thank you!

Please tell the lift driver to STOP for awhile whilst we listen to your video :) Thanks for the video. Just wanted to see how this thing works on the inside. And, it's exactly as I suspected... just wanted to be sure. Cheers dude ;)

i have been on a hour search to find out why fuel is coming out of the pressure release and i now know why… i have a cheap no name one so that probably doesn’t help but i now know that it isn’t normal and that my fuel pump is messed all the way up😭

Can I ask you a question on this pump?

Thanks!

Question, are these supposed to cut off fuel when there is no vacuum applied? I bought a replacement that just flows right through from gravity and I wanted to use it as a fuel cutoff for when the engine is not running as I have a unfindable sporadic float valve issue that has been driving me buts for 2 years after 3 Rebuilds!!! And I cannot find a reasonable vacuum cutoff for a 1000cc engine below a hundred bucks.

Question: Can that pump be used as a oil pump too? Wondering if a vtwin could be converted to a “dry sump” ? Larry

Hey chief have a question hope you could help me with I have a Hobart champion 145 welder/generator it has a 11 hp briggs and stratton engine unfortunately the owner ran it without oil so my question is can I install any size engine in it or would I need to find something similar to it and how about the crank shaft does it have to be the same length size it's that I try looking up videos on engine swap for generator can't find none that will help me

When you switch to a pump from gravity feed how does the engine then get vented, the pump uses the vent pressure so the vent is closed off?

so what you are saying is that if you have a fuel tank capable of gravity feeding the carb, bypass the fuel pump so you dont kill the bearings in the motor?

If there is water in your gas tank I guess it would be a good idea to clean out that fuel pump of residual water

I have a JD 160 lawn tractor and I don't get gas to the carburetor. I put a new fuel pump on and it went around the yard about 4 times and quit.. Is there a way to test the vacuum that runs the pump? And is there anything else I can try?

Can you prime a fuel pump manually?

There needs to be a gauge to check the engine pulse or something ?

fuel return? need attantion.

Is it possible for reed valves to cause a problem with the pulse signal? I have a 2 stroke engine (outboard) that runs fine except at idle, where it idles fine for a bit but then starves for fuel and stalls. I can keep the engine idling indefinitely by giving the primer bulb a squeeze whenever the idle starts slowing down. Once the engine is off idle it runs fine and seems to have good power (boat top speed is same as it ever was and it planes or pulls up a skier no problem). I replaced the fuel pump and there was no improvement. I then built a hybrid fuel pump using the new diaphragms but the old check valves (rubber, the new ones were plastic with a spring) and now it is idling indefinitely but I don't think it will last and I'm not sure why the new pump with the new check valves wouldn't work as it came in the box. Or am I looking at low compression? It is 105psi cold. There is definitely a pulse coming from the crankcase when the engine cranks, but I don't know if it is enough pressure. I also replaced the fuel line with the primer bulb, which made no difference.

can i get parts to rebuild this pump? i have the same one on a kawasaki mule!

Can a bad fuel pump suck oil and allow it to go thru exhaust?

How to fix it

Hey mower medic. Small Engine Nation I’d coming on at 7 ton. I’d love itu could stop in for a chat and maybe join the stream

You need to see a doctor about you fingernails. That lloks like a fungus infection. Four pill , one pill each week will cure that. I'm just trying to be helpul. This post is not meant to be disrespecful in any way.