Outboard fuel pumps

In this video I do a couple of crude fuel pump tests using a pressure gauge and then replace the one-way valves in a four stroke EFI Mercury low-pressure pump. I also show the metal reed valves in a Yamaha fuel pump from a two stroke motor.
For outboard repair information, checkout my website: outboard.dangarmarine.com/guide
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[@joeg.cintron4226]

Excellent and ageless video - helped us troubleshoot and repair our Mercury 30hp, 4 stroke, EFI fuel pump. Amazing how we can count on you mates from down under and not from our own here in the USA! Thank you so much!

[@DangarMarine]

You're welcome Joe. :)

[@esurcylimaf4335]

Great video Stu, you always make things clear and seem easy. Thank you for your tips. I often suggest your channel as reference when people are asking for certain outboard problems, Cheers Rob

[@DangarMarine]

Thanks Rob, glad you liked it and always appreciate people spreading the word. :)

[@caleymcglynn725]

have to say, really appreciate your uploads. no boat experience, just bought a boat and with your videos i have serviced the impeller, carby, shaft seals, lower unit oil change. and now the fuel pump. thanks very much stu

[@DangarMarine]

Glad to help. :)

[@jeremybro7016]

This plus the VST video saved me a fortune. Local marine shop couldn't figure out what was going on. These two videos were exactly what I needed to do it myself on a 60/40 EFI mercury jet. Thank you SO much! Very valuable videos.

[@DangarMarine]

You're welcome Jeremy, glad to hear the vids saved you some money. :)

[@AhmedAdly11]

Your videos have made me a hero :) In Egypt, we have hundreds of live aboard dive boats and each boat has a couple of RIBs with 40HP yamahas. Now our sailors over here have hearts of solid gold, but they are pretty careless with our equipment. We all suffer terribly with keeping the outboards well maintained. So after watching your videos, I started doing these odd jobs and it has had a huge impact. Sailors from other boats keep coming over for me to fix theirs!!! Thanks for the greta videos!

[@DangarMarine]

Great to hear! Someone has to keep these old motors going. :)

[@Jubi316]

Here from America , I just recently rebuilt my Mariner 200hp had the block bored and had new pistons , bearings and more . Runs like a beast . I've been a mechanic for alittle over 20 years but still learning everyday , lol

[@DangarMarine]

Nice one, glad to hear is running well after the rebuild. You're dead right though, there is always something new to learn!

[@badger305]

If you don't mind telling, how much was the rebuild versus the price of a new 200hp engine?

[@dtrutza]

Great video as always. Really enjoy watching them, and I learned a lot. Thx

[@Augn-ff3dp]

Dammit mate I needed this 18 hours ago.. Thanks for the video regardless all great info once again.. Successfully cleaned and tuned my carbys just from a couple of ur videos so far, confidence inspiring indeed. Saved me a few hundred atleast

[@DangarMarine]

I've heard that a few times! I had been meaning to do this one for a few weeks too... Glad to hear the videos have been saving you money. :)

[@greggaaron1542]

Hey I just wanted to say thank you for all your videos very informative you do a really great job thank you again

[@ronaldcach2779]

Thanks again Stu, you are a life saver. Ron from Michigan USA

[@ronaldarevalo3513]

Great video!!! I have been having fuel problems I just changed the priming bulb and it didn’t work so now this will be my next thing to check. Again thank you sir you are a big help and I did learn a lot from your video.

[@DangarMarine]

You’re welcome, good luck!

[@captaindon2967]

Sent this Vid to my friend perfect for his motor- Thanks Stu

[@DangarMarine]

Glad it helped

[@WillsGarage91]

Great work Stu!

[@DangarMarine]

Thanks Will! :)

[@donmoore4259]

Just wanted to say thanks for your taking the time out, in making your videos. Great stuff! We all enjoy them, and are so helpful... I'd like to request, when you find the time.. Will you make some more videos, covering motor Bogging...Why?? Is it in relation to Fuel pump, or in the carbs? Mainly, just more videos on Fuel Pumps, and Carbs... Thanks again, Don.

[@gmcbride6306]

Great video. I noticed on my old pump that after removing it to test it you can pump the button plunger that goes in the motor and feel if it holds suction with your finger over the pickup side and feel the pressure on the outlet side if the pump is good.

[@joemole5135]

Awesome video this video explained how the fuel pumps work didn't know much before it. I wish you would put videos up more often like two or three times a week don't worry about editing them just put them up real time I'll still enjoy them a lot thanks

[@DangarMarine]

Hey Joe, glad you liked the video. I am working on finding a way to make more time for at least one mid week video each week. I had started doing short "quick tip" videos and I really need to get back to that.

[@DangarMarine]

Oh, and I also have the 'dangarstu' Instagram account for little midweek bits and pieces.

[@brenth7774]

Wow, extremely thorough on the wire wheel about the old loctite at 8:15 Great job on that.

[@JimGrady67]

Great videos! The one on the VST really helped me with my 2003 Merc 40hp 4 stroke. I was also surprised to see I can buy a new low pressure fuel pump for cheaper (96USD) than a company wanted for the rebuild kit (120USD). Thats if they had the right kit number. Keep up the great videos!

[@DangarMarine]

Thanks Jim. It's weird sometimes with parts. It also pays to look first as the prices can sometimes be surprising.

[@TimsWorkshopTJY]

hey that looks just like my 4hp yamaha fuel pump I thought was leaking internally but was the cheesy finger clamps. changed them out with SS clamps like you showed on one of you other videos. the hand pump is a must have for pressure leaks. good video. Thanks

[@DangarMarine]

Thanks mate, those pump / gauges sure are useful, that's for sure. :)

[@emtdanny520]

thank you for you time to make this videos.

[@2sheetstothewind484]

Very informative. Gotta buy you another Fosters. Bought an `86 90hp merc w/16ft runabout. Been running good gas and Sea Foam. Got it going 36mph top speed. Gonna rebuild/replace the fuel pump for maintenace. Hope to get more speed but I think that`s all she`s good for (36mph).

[@DangarMarine]

Thanks mate, glad the vids have been helping you. :)

[@mattfoss423]

Comedy gold stu.. hahah I have no idea how you manage to keep a straight face!!

[@DangarMarine]

Anything's possible with editing! :)

[@nickbeard2821]

Dangar Stu every new youtube account I make your the first channel I sub to. I'm trying to diagnose my 25 efi merc right now and I'm pretty sure its the pump.

[@troyjacka598]

was awsome love this site got all my gears now happy as larry lol cheers m8

[@DangarMarine]

Hey Troy, glad to hear you've got all your gears sorted out.

[@Fireship1]

Another great video from you Stu. I have two of these guys on my Yamaha 150. I was told both were replaced for preventive maintenance, but now I know how to test and overhaul them if needed. They are less of a mystery to me now! We have ethanol blended fuel here in the US that isn't the best for boat fuel systems. I wish that they would go back to good old regular gasoline!

[@gnrphil]

Easy way to check those is by loosening the mounting bolts a bit and then give the primer bulb a squeeze, if they're bad fuel will leek out of the hole in the back that Stu pointed out in the vid. They're easy to rebuild but a new one is only $40. Don't tighten the mounting bolts up too tight, they only need about 6 ft lbs or so.

[@DangarMarine]

That's a nice quick check for a leak in the diagram, I like that.

[@ronpowell2373]

Yeah, we have ethanol fuel here and the government mandated that all service stations must sell it. However along with that law is that the blend is a maximum of 10% and bowsers have to be marked (in most cases it is very poorly marked, and hidden by other 'power words' ). So generally if you stick to the major brands and use 95 or 98 RON fuel you are OK in Australia. You can get 91 non ethanol in many servos but you have to be careful as the 10% ethanol is often in the same pump . In saying that we still get bad fuel! We filled up last weekend and ended with 50 litres of bad fuel (diesel+E91 in a supposed 95 pump!) last weekend which killed my engine with in about 500metres from the dock! So now I have another major winter project - or a new motor - to be done by October.

[@Fireship1]

Ron Powell Wow Ron, sorry to hear about that. I guess the whole ethanol and water issue is more widespread than I thought. They do sell non ethanol fuel here in the US, but it's very hard to come buy. A search in my state (New Jersey) shows only two places to buy it in the entire state. (It's a big state here too!) And none of them are anywhere near me. Best I can do is try to burn the fuel in the tanks ASAP and not let it sit. I also dose it good with an ethanol fuel treatment with every fill up of the boat.

[@darrylpechey9162]

Thanks for pulling the Yamaha pump apart. Now I see why a lot of places just sell the pump diaphragm.

[@DangarMarine]

Yeah, it is certainly the most common part to fail.

[@maxspain46]

@@DangarMarine where can i order the Diaphragms?

[@irvingguerrero6052]

Great video as usual. I am motivated to trouble shoot my Yamaha fuel issue. Thanks

[@PhonEGeniu]

great video!

[@DangarMarine]

Thanks mate. :)

[@LifesAdventures555]

Haahaaahaaa!! I think this is the first time I have been made to laugh while viewing a marine repair video! So you gave him the shirt off your back!! Love it!!

[@johncarilloiii7828]

Excellent video, as was the VST service video. Would like to see more. Learned a lot. Do a video on servicing a 60 hp efi outboard. Love the tips and tricks!

[@hkm_865]

Felt like Dangar today, did a powerhead swap on my Johnson 115. The VRO pump makes me nervous though

[@DangarMarine]

Nice work. With the VRO pump just make sure you start up with premix oil until you are sure that the oil in the reservoir is being consumed.

[@ductran7058]

I learned so much from your video. Si fu.

[@mgav1975]

Thanks for the video. I am trying to convert my VRO on 1996 Johnson 200hp 90 degree to a premix conventional direct fuel pump. I was going to run 2 aftermarket fuel pumps in series and cap the extra pulse port- will this work?

[@alfalfatheboss8317]

good vid

[@DangarMarine]

Thanks you!

[@danidimesss]

Hey Danger! Your videos are always my first choice when marine work is needed so I have a question. I have a 2013 yamaha fxca 250 and recently on the water was having fuel pump issues. (Engine dying completely as if starved of fuel and primer bulb being the short term solution) Got it home and investigated the low pressure fuel pump which is electronic and absolutely no fuel coming out of the line which should be feeding into the VST. Went to the fuse box and found the fuse was blown. switched it out and fuel pump worked for a short time then nothing. Fuse blew again. Tried bigger fuses and they all have blown. Is my pump shot or is something else causing the fuses to blow? Thanks for all the great teaching!!!!

[@pandonia77]

Can you do a video that shows what are the most important or crucial tools/gadgets/testers to own when a noobie is considering to maintain and service their own outboards?

[@DangarMarine]

Sure, that's a great idea. I'll try to get to that one soon. :)

[@bfflorida2311]

You vids are 👍👍👍

[@DangarMarine]

Thanks mate. :)

[@donmoore4259]

First, thank you for taking the time to put together these very informative videos...Now, question about fuel pumps.. I'm having an issue with an 1987 Johnson 90hp v4, which I just purchased and have it on the water several times no problems.. But, now it boggs down, doesn't die, just boggs down.. seems to happen once you try an open it all the way.. Things I've covered so far...One, I changed out the primer bulb, and switched over to a different tank of fuel.. So what next?? thanks Don..

[@DangarMarine]

I would make sure the carb bowls are full of fuel by draining one straight after it happens. If they aren't it could be a dodgy fuel pump. If they are full it could be a problem with blocked main jets meaning the carburettors will need a clean and perhaps the float levels set.

[@newyota1]

Good video.I thought maybe you would be showing a fuel pressure gauge installed in-line to show actual pressure it was producing.I just acquired a fuel pressure gauge to install between pump and carb. on my 85' Johnson two stroke to test.

[@DangarMarine]

I used the fuel pressure gauge in the original video that fuel pump came from, but unfortunately the boat this goes on is no longer hear so I can't test it directly. It is a good point about testing one in the future though. I'm normally only interested in fuel pressure with EFI motors but it would something worth checking for carburettors too.

[@jimbogasoline8559]

Hey stu! I know you get a lot of request for vids. I have a request that im sure most would like to see. When you google reading a spark plug, the info is vague and hard to tell. A quick tip on spark plug color reading would be great and a lifesaver. Could save someone from a piston rebuild by reading plugs. I myself just know dark is oil and white is lean. Thanks and please keep up the great work!

[@DangarMarine]

Good idea, reading spark plugs is an important thing to learn about. I'll start keeping interesting spark plugs in a tray somewhere and when I have enough of them I'll do the vid.

[@mattdevries7540]

Dangar Marine I have a 1966 Evinrude 5 hp, recently replaced a leaking fuel pump, connected everything and it fired up but it won't stay running more than 5 seconds, cleaned the carburetor the previous winter and also replaced spark plugs...any ideas on what the problem is?

[@jimbogasoline8559]

That sounds fuel related. Try choking right before it kills and see if it keeps running. it could be something else but i would start there. Mine did very similar after i rebuilt my fuel pump and all fuel lines and carbs. I just KNEW it was electrical. I bought an extra fuel connector and ran fresh fuel on a different tank. My problem was i was sold water as fuel from a marina. Since i just bought the fuel it didnt even cross my mind. Pulled my fuel/water seperator and it was FULL with water! Fresh non-ethanol fuel my ass! The marina screwed me. So try fresh fuel this time. Or dump some of your fuel in a glass jar and see if it has water in it. Let it sit for a lil bit and you will see the seperation if it is bad. Hope this helps and good luck

[@mattdevries7540]

bigfat hotdog it will stay running for a few longer seconds on full choke but still dies... just put new fuel mix in a week ago... could the carb have gotten gummed up only 4 months or so after a good cleaning?

[@mattdevries7540]

bigfat hotdog also it only starts using starting fluid but once that's gone it dies immediately

[@chugs]

Love your videos Stu, so Briiliantly simplified for lamen like myself.. My mariner 40hp efi has been beeping a continuous warning beep.. Apparently oil pressure, or overheat. I've replaced oil, oil filter, cleaned high pressure pump, replaced both fuel filters and bought all new fuel lines... Still getting the dreaded beep.. I'm going to replace this low pressure pump now as the cooling water runs through it so hoping it might help? Any other suggestions would be amazing..?

[@jasonwalsch5559]

You are awesome, One of the best Channels on KZbin for boating. Could the fuel pump being old /weak cause a weak jet from my carburetor/ not enough fuel?

[@DangarMarine]

Yes, if the fuel supply isn't high enough the level in the carburettor float bowl will be too low and the mixture will be lean. It could be a carburettor problem too though.

[@TheRandomviolator]

Dangar Marine, Thanks , I rebuilt the fuel pump. Think I've got it sorted out , still some adjustments to do. But I think it's time to replace the tachometer

[@anthonybehr350]

Excellent video! Can anybody tell me if there’s a gasket between the head and the plastic back of the pump?

[@am44_67]

What’s the first thing you would check in this scenario, boat runs great except for at full speed RPMs drop and rise until I slow down a bit?

[@patrickfountain198]

Hey mate, thanks for all the videos, been super helpful when servicing my boat. Quick question - I have a 50hp Mercury (same fuel pump as you've used in this video). Above ~60% throttle it's losing power and sowly surges back to idle then cuts out. Switch it off and on and it's good again up to the 60% mark. Thinking it's the fuel pump or blocked injectors. Any ideas?

[@DangarMarine]

Sounds more like a fuel pump problem.

[@garyr9823]

Thank you for video! What part number gasket kit for fuel pump?

[@ksc5522]

Cant stop watching the second hand on the clock

[@jimmyflynn1764]

hi stu i have the honda bf90 and got the shock of my life because as always every time i use my boat in the sea i get home and next day flush engine properly. well the last time i used my boat i took my top cover off engine and to my shock at the side of my thermostat there is a metal covering with a hose attached well it was all corroded at to buy new metal cover i would be happy if you could show on your videos where the water system flows so that i might be able to watch for any more problems by the way i have the full honda bf 90 diagram pages if you would like me to sent a copy to you i will do so but watching your videos are much more informative

[@DangarMarine]

Hi Jimmy, I've been meaning to do a video on the full path of the cooling water for AGES! Thanks for the prompt to bump it up the list. Stay tuned!

[@HigherPraiseQuartet]

I have replaced my low psi fuel pump and still have no fuel in the water separater. What do you recommend?

[@Lando1214]

Awesome video! Out of curiosity, did you remove the lower cowling to get to this low-pressure fuel pump easier? I'd really like to know to remove that cowling.

[@everchevy]

I just took my low pressure fuel pump off my 2012 Bigfoot and only had to remove the hood latch to get to lower bolt. Diaphrams were trashed. Can't find a repair kit no where.

[@camping56]

Hi the vidoe is a big help im struggling to find the one way valves for my 4 stroke engine where did you get your from please?

[@toml5637]

I have a 2017 90HP merc (they call it the 75,90,115hp, model) It's bogging down at near full throttle. Just took it out today added sea foam injector cleaner , seem to run a little better. But, I want to clean the screens on the fuel pumps. I don't see the FSM on the upper part of the eng. Is it below the cowling, back side of motor? Is it serviced the same way as you've done?

[@ianmcnab9124]

Can you please upload a vídeo on the suzuki df20ar high pressure pump how to clean replace parts of above pump

[@WBU319]

We are working with this exact pump and encountered a problem getting one of the mounting bolts to thread when we put it back together. We backed all four out carefully just one time and three went back in well while the other won’t latch onto the female threading. Do you have a recommendation for how to correct this so that the pump can be fully reassembled? There is no visible issue with the bolt and so I figure that the problem is inside. We did switch bolts and found that any one of them works in the three good female threaded parts.

[@toddthemitchell]

can you tell me which fuel pump repair kit you used? I need to replace those reed valves in mine and cant find a rebuild kit. thx

[@mattfrapple7911]

How good was that black and white valve video cut in!

[@DangarMarine]

Thanks Matt!

[@timven8402]

Just happened to see this great vid. I have -04 BF50A and the oil is getting thin and it smells like there's gas in it. How common is it that gas leaks through pusher rod opening? Can the gasket and rod be changed without buying the whole pump? This may be also a thermostat problem since here in Finland we have pretty cold sea at spring and autumn...and practically always if comparing to Australia😊

[@user-qj2wp7xg4z]

Hey Dangar Stu, what's the best place to order these parts from in Sydney or online? I have the 2 stroke tohatsu fuel pump.

[@user-qj2wp7xg4z]

Hey Dangar Stu, what's the best place to or these parts from in Sydney or online? I got the 2stroke fuel pump . Tohatsu

[@adrianmac4695]

Which kit did you use to fix the low pressure pump we have a similar model.

[@DangarMarine]

If you look your motor up on marineengine.com you'll see they are a section of common service items separate to all the spare parts. You'll definitely find the right kit there.

[@geraldolmstead1335]

very good presentation I go by Jake I'm 73 and in poor health but I enjoy watching your presentations. One question, we have an old Johnson 40 hp. with the oil being mixed by an injection method,do you have a video showing how to rebuild the dual carbs if you do please let me know thank you.

[@DangarMarine]

Hi Jake, I don't have one specifically on those carbs, but other videos on cleaning carbs and installing carb kits that you may have seen. By dual carbs, do you mean that each unit is feeding two cylinders? I've got some carbs like that from an old V6 that had 3 dual carbs on it. I could do a video on that carb if I can find it.

[@guyzoun]

2002 honda bf40. Original fuel pump. Is it possible that engine oil makes it way via the pump plunger/camshaft inside the pump? I noticed very little weeping of oil underside the pump assembly/gasket. Does not smell gas. Excellent video! Thank You

[@Reuldonniedah]

i was looking for the spare parts or repair kit if you like, but can't seem to find it on marineengine.com only the whole pump. any idea what part nr it might be ? i have the same sort outboard: 40 hp efi 4 stroke mercury

[@mg7601]

Where did you buy the low pressure fuel pump diaphragm kit at? I can't find any for sale. New subscriber here, great content!

[@alpoktemornek7833]

Thanks for the video, my suzuki df30a year 2019 cuts power over 4000 rpm after 5-10 minutes ride. It starts and runs very smooth and perfect. Can you give any idea; is it the low or high pressure pump?

[@t-rexvlogs5589]

Hey matte great watch just wonder the low pressure fuel pump to replace instead off rebuilding I thought you mentioned the price was reasonable was quoted $800 -$600 today

[@rob.halpin]

Thanks for this. I have that very fuel pump, bu my problem is that there's no water flowing through it. Can't figure out how the cooling channels are set up in that pump. Have tried vinegar and poking with wire, but no luck. Any advice for me at all? Thanks for all you do here, chief. SOLVED: So I found a solution to the problem. It is a fairly straight shot through to the tell tale hose. It is pretty narrow though, and with age, it gets a little jagged in there, which can catch a lot of sand and shell debris. I used penetrating oil and various size zip ties to "saw" my way through. Required much more physical effort than clearing hose or tell tale, so don't be afraid to lean into it. Hope this helps someone else.

[@stephancordell697]

mine squirts out fine on the boat from the outlet...I cleaned the VSP VST was wondering if carb cleaner is ok to flush through it or will it eat the rubber???

[@googleplusisdead]

You mentioned an O ring wasn't seated on first assembly of the Merc pump, I didn't see anywhere that you referenced it/showed it/where it is? On the Yamaha pump, what does the metal valves seal against, just metal, or is there an O ring or something they seat against? Lastly, what videocam do you use and what software for editing? Thanks, RichE

[@DangarMarine]

It isn't so much an o-ring as a thin gasket that goes around the edge of the pump's cover plate. The reeds on the Yamaha pump just seal against the plastic casing of the pump. As the vacuum tests show, they down really seal completely, they just restrict the flow in one direction enough to cause fuel to mostly keep moving in one direction. Camera is a Panasonic v770 and I use Final Cut Pro for the editing.

[@taylorcole19]

I can't find the kit for this I need the exact black rubber plugs but I'm not sure on the size

[@josecarlosgamez3718]

I got a 1986 bayliner 125 outboard motor, starts with no problen but when i acelerate to go fast ,the power go off and on off and on , what it can be , the carbs, or fuel pump? Or someting else?

[@ericturostowski6462]

Super

[@DangarMarine]

Thanks!

[@niknahevad]

I just re-watched your video on pressure testing lower units where you made your own pressure-tester. In this video I see you've bought a commercial hand pump pressure tester. How much was it and where did you get it? You still reckon a DIY version is good enough? Thanks for the video

[@DangarMarine]

Hi David, yep, DIY version works just fine, it's just a little bit more fiddly to use. The one I bought is like this www.ebay.com.au/itm/Hand-Held-Vacuum-and-Pressure-Pump-Tester-Kit-Brake-Fluid-Bleeder-Adapters-/291832545459?hash=item43f29340b3:g:GcMAAOSwc-tY7yHW

[@mijead00]

Thank you for your videos. I wonder if you have tips on a good Mercury website where i can see the electricity schedule and how everything is connected? Thanks in advance Best regards Mikael from Sweden

[@DangarMarine]

Hi Mikael, generally with wiring diagrams you need to get the service manual for your motor. You can try finding it on tradebit.com and readmanual.com

[@mijead00]

Thanks so much Stu⚘🤗

[@ianmcnab9124]

Can someone explain on how to replace parts of a suzuki outboard df 20ar four stroke high pressure pump

[@SirTrampe]

Hello Danger, Love your videos. Been following you for a while now. I have a question i have you can answer for me - I have a suzuki DF25 V-Twin 4 stroke motor from 2008. It is in fairly good condition. - starts everytime, runs perfect in idle. But when i give it some throttle it will start to act up, and sometimes die completely, then first time i pull it starts right back up no problem and run smooth again, but then it will die on me again if i give it too much throttle. It only sorta happen when i give it like 25% or more in one go. If i slowly climb my way up to full throttle over lets say 30 sec. it wont happen. What can that be? im lost. Any clue what it could be ? Thanks in advance :)

[@DangarMarine]

Hi mate. As fuel is heavier than air, when you accelerate there is a lag where a motor with go lean unless something is done to compensate (like an accelerator pump that gives a little squirt of extra fuel as you push the throttle). Sounds like either this mechanism isn't working or perhaps you have a vacuum leak where extra clean (non-fueled) air is being sucked into the cylinders. Check that the carburettor is well sealed against the block with a good gasket to start with.

[@inthenameofmyfather3836]

hi i was wondering if that plunger in the back could leak oil into the fuel ive got a lot of smoke like its burning a lot of oil 4 stroke 40 merc thanks

[@d.johnson499]

Great video on the fuel pump. I wish we had a guy like you here in the Atlanta area, someone who tinkers with older motors. My 1986 model Mercury 75 HP would generate a lot of work from you! As it is, I have to do it with a book and helpful videos like this. Question about fuel pumps: yesterday I serviced mine, trying to track down a fuel problem that is giving me some stalls and bad hole shots. The rebuild kit I got included a plastic 'cap' that fits over the end of the spring that contacts the diaphragm. My pump did not have that plastic cap, nor did I even know such a thing existed, because I always bought just new diaphragms, gaskets and check valves separately for pump service, never in a proper, everything-included kit. Because I never had that plastic cap, the end of the spring would always poking into the middle of the diaphragm. Could that have been a cause of my weird fuel delivery symptoms? Here's a picture of the spring: i.imgur.com/IcF3K9A.jpg and this is the plastic cap: i.imgur.com/5yeWJRH.jpg

[@DangarMarine]

Hi mate, can't say I've seen that exact fuel pump so I'd hate to give you the wrong information but it makes sense that something should be there to protect the diaphragm. Something else to be aware of though is that sometimes these kits come with parts to cover a range of outboards and not all parts are needed for your exact model.

[@jimbogasoline8559]

Great vid. I have a question on thread sealers like the loctight you used on the fuel pump. My merc service manual says to use loctite 271 on the impeller housing. When i went to buy it at autozone i saw 271 is the red loctite that the label reads as "permanent, not removable with hand tools". Every time i did the LU service i actually used grease on the bolts. Would I be better off still using grease, anti-seize, or the green loctite that states it IS removable by hand tools? Or should i follow the manual and use the red loctite? Thanks a bunch and can't wait for the Johnson LU vid!!#

[@DangarMarine]

Hi mate, good question. I have used green loctite before, but on these small bolts I've always found the red to be removable with hand tools. We use a Wurth loctite in the shop so I'm not sure what the exact equivalent is. I think some sort of thread locker is a good idea on water pumps in theory, but I've never seem them come apart even without. With regards to using grease, I think that is better for the larger bolts like the ones that hold the leg on as they can be torqued up nice and tight.

[@jimbogasoline8559]

Cool thanks

[@dustinabercrombie8939]

My 06 mercury 4 stroke efi is losing prime on warm starts. Could this be a possible issue or does it sound like high pressure vst? I've replaced primer bulb and main fuel line but problem seems to be getting worse. It takes about 10 attempts to start but once it cranks the engine runs fine.

[@Toto-nt9ll]

Thanks for the video. I have a 2013 Mercury 60hp efi and it is bogging down at full throttle after being out on the lake for a while, going a mile or tow - stopping to fish and then restarting. It starts fine, gets to plane and then will bog down at random times. If I throttle down and wait a few seconds it will go back to normal. Just wondering before I start trying to take things apart - if you think this would be the best place to start? The fuel filter has been changed and the motor has had no other issues. I took it to a marina and they could not find any issues but they didn't do anything but change the filter. They lake tested it and said there were no issues but it continues to bog down on most trips. It also seems to do it more when it's warm out. Most of the winter we had no issues.......just don't feel safe out there with this happening. Thanks for any insight.

[@DangarMarine]

I would start with the simple things like checking the breather valve is open on the fuel tank and that all the fuel line fittings are tight and not sucking air.

[@kory1212]

Hey stu I really need your help I don’t have any good mechanics or Honda dealers near me , I’m having a issue with my motor I constantly need to prime my ball and notice it’s never stays hard and when idling it doesn’t stall but shakes pretty bad . I can’t find any info on the part I need or if I should take it out and check the fuel pump . I’ve replaced the gas lines fuel filter clean gas fuel water separator and nothing any advice would be great !

[@cree-rez67JB]

LoL.. good one about the t-shirt

[@pablodiniz1344]

Good morning, did you have the 4-stoke engine manual?

[@DangarMarine]

Yes.

[@capt1eyedwillieb-radd30]

An Yamaha 50LTRA 03 is it best to rebuild, clean, or just replace the fuel pump assembly...

[@DangarMarine]

It depends on the price you can get the fuel pump assembly for really.

[@johnmelissalawrence6649]

Quick Question- I am cleaning the carbs on a 2001 30hp 2 stroke Yamaha for my dad, he let it sit for 5 years with ethanol gas in it. So I cleaned the carbs dumbed the old gas and had him get new ethanol-free gas it started right up but after a tank of gas was idling rough. I pulled the carbs and the jets were clogged again not as bad but some of the jelly was in the system still. So can I open and clean the fuel pump without having to replace gaskets or diaphragm? I also ordered a new hose and primer bulb and plan on scrubbing the tank clean. cleaned fuel filter also again.

[@johnmelissalawrence6649]

or do you think to clean the tank, fresh gas, seafoam, new hose, and primer bulb, with clean carbs and fuel filter with clean it out good enough?

[@bradeagle9724]

Having issues with my yamaha F115 making oil and recently started only reaching 4500 rpm (5800+ was max before). Dumped the oil and refilled to about halfway up the dipstick. Ran it 70-80 miles in one day and it starts running at 4500 and wanta to die like its starving for fuel. Bulb is partially collapsed but pumping while running doesnt do anything. I removed the mechanical LP fuel pump and no tears in either the rubber or clear plastic diaphragms. Could the one way valves be letting fuel into the crankcase somehow? Also have an oil leak what appears to be an upper crank seal. Could excess pressurization of the sump cause seal failure or leakage? Wish the yamaha LP pump wasnt $200...seems excessive for what it is.

[@pandonia77]

I thought you said "Danger Studio here" at the start of the video :)

[@DangarMarine]

Works both ways I reckon. ;)

[@tinyfordtruck]

hello sir..I'm working on dt 140 suzuki.and I think I'm having fuel pump issues as well..it's getting fuel to carb but don't think it has enough pressure to supply for motor(can fill bowls up just not enough to pump into motor..)i have tooken one outlet line off and turned motor over and it pumps but if I see how much pressure it has by putting finger over and it doesn't push any fuel by my hand...I dunno how much psi those should be pushing..but is there any other way to test with out gauge tool?

[@ronpowell2373]

Diaphragm pumps don't generate much pressure - 2-3 psi is typical, which is why they are used to feed carburetors ( low pressure means they don't push needles off seats) and don't need a pressure regulator. You should be able to stop the flow with your finger .

[@ryanschreck9722]

I have 2 of the pump at 11:17, Yamaha. When I squeeze the fuel bulb, fuel leaks out into one of the holes where the mounting bolts go. That’s very bad right? I’m surprised that both of the pumps I have do the exact same thing.

[@DangarMarine]

Could be a couple of things. Either the diaphram / gasket in the pumps are bad or the needle and seat in the carburettor isn't sealing and the crankcase is filling with fuel through the throat of the carburettor. I would take one of the fuel pumps apart first and carefully look for tears, holes or pinched sections.

[@KurtBergNielsen]

Someby know where to buy the handpump or the type of it ,Thankyou

[@wac4christ]

Hey Stu! Thanks for the videos brother! While watching your choke video I had a thought that may be my be the answer to my bogging at wot. Can you confirm please: The read valve on the 2nd fuel pump in this video (used on 2002 Yamaha 90hp), is what I have. Should both reed valves sit closed (touching the seat), when installed. If one is lifted enough to see that it is not seated (maybe 3mm gap), would that cause bogging at wot? I will need to confirm, but I think I have this condition with one of my reed valves. I am getting exited and cant wait to get home and check my pump. I will comment if that is the problem, because as you said, I have never seen an issue with those reed valves, but I may have missed this a few night s ago. Thanks brother!

[@drlangattx3dotnet]

Hi Stu. I looked for a fuel tank video to be appropriate for a question. Anyway...I want to have two outboard fuel tanks on my RIB. Waht is a good way to plumb them? Crossover pipe ? Totally separate? I have one already, a 12 gallon Moeller. Thanks for any advice you can give.

[@DangarMarine]

Hi Donald. Generally I would keep them separate so that when one runs out you know you have used half your fuel and can start planning your return journey. Having said that, there are plenty of boats setup (catamarans are a classic example) when they draw from both side tanks at the same time to keep the boat on an even keel.

[@drlangattx3dotnet]

I will probably do a separate line for each to a tee with valves and then to the filter. But how do they do the catamaran setup?

[@rickbest7361]

I need to know how to disassemble the cam shaft button that pushes on the diaphram! Thats all thats bad on my engine.

[@NorthernIrelandFishingReports]

Hi Stu, can you please tell me if a bad diaphragm in a fuel pump would cause the engine (suzuki dt65 oil injection) to stall when going into gear, under load. Then intermittently go into gear but not reach high revs. feel sluggish, I think I may have this issue and trying to work out what could cause this. Ive cleaned the carbs and changed plugs and still getting this. But only under load. thanks.

[@DangarMarine]

It doesn't sound like fuel pump to me. I would do a compression check on the motor and see if the carburettor bowls are still full of fuel when it starts to happen.

[@NorthernIrelandFishingReports]

hi Stu thanks for responding. im near sure that the bowls are still full when this happens, if not fuel pump. what would be next thing to check, and dont have compression tester unfortunately. a friend said it may be getting to much fuel through the diaphragm and drowning it out on throttle, strange thing is it goes into reverse without stalling

[@miloyoung5031]

Good video Where can you find a kit to rebuild 40 hp efi fuel pump?

[@DangarMarine]

You'll be able to get one from MarineEngine.co

[@tonymitchell4720]

Hi, really enjoy your vids and hope your haveing fun on your new bike. I have a 15 hp yamaha 2 stroke, that I think has has a fuel problem. 3 times when the fuel tank gets below half full it has died on me. I can pump the bulb and it will start, idle about 5 seconds and die. Have cleaned the carb and checked the diaphragms and replaced the tank to motor fuel line and bulb, still same problem. Other than preasure, is there a test for the portable tank? Should I be looking elsewhere? Thanks

[@DangarMarine]

I would be looking at the pick up in the tank and making sure the breather on the tank is open. It is strange to get so far (half a tank) and then fail. I would also check that it isn't something unrelated like the motor overheating.

[@tonymitchell4720]

Dangar Marine Thanks, for the info on the tank. Have a steady stream comeing from motor when it dies. All 3 times we were fishing at end of day and motor had been stopped for over an hour before we started back to dock which was about 3 miles away. Probably the shrtest run we made all day. I will test the temp and let you know what I find. Thanks again.

[@TheJstringer]

what kind of pressure gauge pump is that at the 10 min 30 sec mark?? great video as always

[@DangarMarine]

This one I presume kzbin.info/www/bejne/op_Li3mkasyefZY

[@bqpharm]

You wanna check the clock battery behind you, bud, looks shot! Great videos though.

[@dangnomen]

thank you! im struggeling with my boat, a mercury 90hp 4 stroke 4carb engine, on full throttle it wont go full rpm.. i opened my fuel pumps (1 pump serving 2 carbs) and found the "sealant gasget"? full of some white powder, tho i cant seem to find a leak, tho there was some sandlike sort of grainy stuff in the chambers, so i cleaned them out, hoping it was the sinner, maybe blocking some valves or something... and i dont want that stuff in my carbs. cant seem to get my membrane off tho, but i cant see any damage... i see some fuel getting into the water but i cannot find where it comes from... its an 2001 model.. do u have any ideas?