I did a fairly long list of parts swaps on my 2002 Yamaha VMAX 200 in the last 8 weeks. Thanks to your for helping to guide me with multiple videos on the same engine. I replaced thermostats/gaskets, VST filter/gasket, primary fuel filter/gasket, fuel primer bulb, post primary fuel filter 1 way fuel valve, new oil pump/strainer, new reservoir low oil sensor, engine oil tank sending unit, and usual lower unit oil and water seperator valve. Runs like a DREAM. Cranked immediately on just a tiny bump of the key. On examining all parts swapped I think the thermostats were shot which caused a shut down and my deep dive into this overhaul. Engine 22 years old. Only 300 hours. 2nd rebuild on the water pump on deck and good for another 5 years min in local fresh water. Thanks so much for your replies an assistance!!

Thank you, tomorrow I’m going to try mine.

Thank you! I had two bad ones.

Many thanks for sharing your knowledge!!

Thanks I appreciate that information that you have given to me

Hey Carlos, thankyou so much for your video, I have the same symptoms and will give this a try as soon as I'm home. I have a spare pump to try. It's a honda bf50a Thanks man subscribed 👌

Thank you so much for making this vid! You just saved me from buying all new low pressure pumps. I’m still troubleshooting but I think this will help. I’ve got a Yamaha 140 salt series 2 stroke that bogs out after about 10-15 seconds of wot. Carbs are squeaky clean. Gonna change fuel hoses and check low pressure pumps.

You’re my hero

Great information! I have a 2002 Mercury 200 optimax just got rebuilt cranks up fine idles good but once I put it in gear it tends to die off and won’t accelerate. Any suggestions on what I can check thanks 🙏.

Thanks for info ❤

Yep. Have the same motor and had issues getting above 3500rpm. Did this test and lower pump poured gas out when the bulb was squeezed.

Dude thank you so much

Thanks

2003 Nissan 120 two stroke. The throttle control doesn’t throttle up until it’s almost all the way down and it’s super tight when about full throttle. Keeps hitting dead spots at full throttle as well

So helpful

ok, i got one for you. last time out we were coming back to the launch and lost half power or actually down to 8 to 10 mph. just about wake speed. I haven't tried to figure it out yet but was able to run the motor at home with fresh water and then winterize it for last year. Any idea what would cause this. I did rebuild the fuel pump a few years ago and for fun tested everything on the motor doing my own videos. one thing that i have neglected is putting a new fuel filter on. I drain all the fuel out of the main tank and used it in the car so it's empty currently. I have an auxiliary tank to put non-ethanol fuel in to test it but not at full rpm. will have to take it to the lake to run it and probably next year.

2005 VMAX 200 hp. Engine starts great even cold. Run a few places then it doesn't start. I waited about 30 minutes then it started. Once running lake it just shut down. Then again hard to start. Any recommendations. Thank you

Good tips in this Video, would these cause primer bulbs to go soft ? (Intermittently) I’ve replaced primer bulb and all fuel line between engine and tank/ water separator. After mine quits and hand prime it will run fine for hours/days before this occurs again and engine is starved of fuel. No anti-siphon valve on tank. Fuel vent is free and clear..

Hola .. mi Motor funciona perfectamente, pero cuando descansa un par de horas, la pera (bulb) de la manguera pierde presión y tengo que bombear para que vuelva a encender, sería esa bomba que enseñas en el video la que me está dando el problema? Es un Yamaha 25 enduro dos tiempos, saludos y gracias!

What is the best way to winterize your boat motor. Would you recommend a ball valve to shut fuel off and let the carbs run out of fuel or what do you recommend

Just tried this on my 78 25 hp evinrude that is having trouble delivering power when throttle is applied, cracked those 2 screw lose and gas leaked everywhere time to order one

I have a Yamaha 200 2 stroke and it only starts if I give it gas or put the choke on, a week ago after starting it cold it started all day in one go, now 2 or 3 hours pass and it does the same thing, the motor has no missfire

Great info. I have a 2016 F150 that sputters at rpm over 4000. Runs perfect below 4000. 250 hours. I change in-line and onboard filter ever spring. What was also confusing I had my wife take the wheel while it was sputtering and I tried pumping the primer bulb. It was hard as a rock. Maybe the bulb? Any advice?

Hey. Thank you for these videos. I have a v- max 115 yamaha where it runs for about 15 or 20 minutes then sputters an cuts off. I pump the ball then try to start it and it starts but when I put it in gear it sputters and stops. My mechanic has told me the pressure is good. But it just seems to be running out of gas between the ball and the engine. Any suggestions?

I have a 2004 mercury Optimax 200. Worked good last year, when winter was done took it out on the water has kind of a hard time starting at idle or in gear with little pressure. It’s sputters, the motor shakes after about 10 seconds. It will shut off go to start it again. It starts right up but it’ll sputter right away. The faster speeds it seems ok. What do you think?

I have a 90 horse Yamaha four-cylinder 1985 model I recently changed the power pack and I've had it 2 to Marine mechanics without fixing my issue. Boat seems to run good at high speed but stalls at trolling speed. Carbs have been clean bowl reset. Sometimes at full throttle you can hear it bogging down and the boat goes slow and then something will suddenly change and it picks up and runs great. Also sometimes when I sit in fish even after the engine is warm I have trouble restarting the motor

@reelteasefishing My Yamaha VX225 starts and idles fine. It revs fine on the hose, but won't rev past 3200 rpm under load in the water in forward, but will rev fine in reverse. Do you think the fuel pumps might be the issue? Thanks for the great videos and information.

Hi there, thanks for the video. I have a 130hp yamaha saltwater series 2 stroke. It won't start, coughs a bit in the choke like its going to but won't fire. Have changed plugs, made sure i have new fuel, choke is definitely turning on, fuel is getting to the bowel. Have tested the low pressure pump as per your video but no signs of a leak. Could it still be the low pressure pump as there's not many more options?

I have a Suzuki df 70,,my low pressure fuel pump is cam driven,that pumps the gas into high pressure pump in the vst ,,isn't it sort of the same test for this one,,unbolt it out of the hole,,pump the bulb and check for leaks ,in this case it would be leaking gas into cam shaft,not good

Does this Carry over onto a Honda fuel pump?

I have a Yamaha F150 LB currently it’s making oil. When I pull the dipstick out, oil gushes out. Oil smells of gas. I will check this tomorrow. This was my thought that I had a bad fuel pump leaking into the crank case.

@ReelTeaseFishing, I have Yamaha OX66 225hp which is currently leaking fuel out for the lower unit. I have change the fuel injectors and all 6 sparks plugs, what do you think this could be. thanks

Great info on the low pressure fuel pump. I am wondering if mine are bad, I think I have two of them. I have a 2003 200hp Yamaha HPDI outboard motor. It starts right up and revs no problem but in the water when I put it in gear it will not get up on plane, I can idle in gear and move around but I can't accelerate. Any suggestions are greatly appreciated.

Appreciate this video as I am trying to diagnose an issue I am having with a 1996 Mercury 200 EFI. Engine starts great, smooth idle. no stall or sputters. Temp is normal and boat hits 58009-6000 RPS at WOT and hits 70 mph. The issue is that it takes 3-5 attempts to get it up on plane. I have ran the Same prop (with prop plugs) and pitch since I bought it new. I have changed the primer bulb and main fuel line from the tank to the engine. I have the changed the main fuel filter and the impeller, and the ECU. Any suggestions for what be the cause of the struggle to get up on plane?

I have a 2003 saltwater series II 200HP boat was sitting for 15 years no fuel is getting sucked in all lines have been replaced what can it be the fuel pumps on the motor I have two that look like the one you just showed one on bottom one on top

I have same engine mines at wot it boggs down but does not shut off I let off of throttle then it will pick back up and feels sluggish I am going to test the pumps like in video also someone told me could be fuel pressure regulator would that cause the engine to run sluggish?

Have a Yamaha 300 HPDI only problem I am having is when I start to plane runs good all the sudden, it starts to bog down like it’s losing fuel any recommendations

Great video. I had an issue this past weeekend. Yamaha 50hp 2 stroke wouldn't go past 4k rpm at WOT. But after about 25 mins of leaving it at WOT it just goes 6k +rpm out of no where, back to it's expected operation. A few minutes later i went over a small wave then it immediately went back to not going over 4k rpm. I can't seem to figure it out

Having the same issue. Had a start and stumble. Then, it started rough and then normalized. It runs fine at 3500rpm but once I throttle up, it falls off, and my starboard engine overpowers the port side and makes it pull hard left. I'll check that next and see if I have that issue.

Hey Carlos I have a 2003 Yamaha 150 v max. I have 2 fuel pumps 1 you said is the low pressure fuel pump, is the other one a high pressure fuel pump or how do they work. The motor just cranks but does not run. I think it the carbs. When I first went to start it sound like it was going to run , but now just cranks. I think it was old fuel so I am thinking of taking the carbs out and cleaning them and I cleaned out the old fuel from tank. On the carbs, clan I just open them and clean them or do I have to get a rebuild kit for each one.

2 stoke 50 hp Merc. Run with bump at full, chokes at slow speeds and idle. Continually pushing the key/choke? manually fueling carbs got me back to the dock. Is this a symptom of bad fuel pump? I am handy but not a pro mechanic. I have changed hoses everywhere no air ??? New sparks. I am quickly running out of options. Am I on the right track? Thanks for the share dude it helped me in this situation.

Would a bad field pump make my prime and bulb go soft when it runs

Hey my ox66 surges when I’m throttling it. Rpm goes up and cuts out then kicks back in. It starts and idles fine. I replaced high pressure pump, clean injectors, new plugs, I even ran it off a 5 gallon can to eliminate fuel tank and I’m still having the same problem. I used an inline glass spark tester while engine running to watch each plug fire at a time and neither stop firing at any time. I was thinking it was the neutral safety switch but all are firing. Could it be the oxygen sensor? Could it be the stator is still bad?

I have a 2011 yamaha 115 it’ll turn on and run fine but after starting it a couple of times. It won’t start you’ll hear it trying to start but nothing happens. So I pump the ball and after a while it’ll turn over. Do you have any idea what is causing my issue

I have a 2014 etec 90 hp. Starts right up and runs good. After running 15 minutes to my fishing spot, i turn off the engine. Each subsequent start, the boat starts fine. But it stalls when i try to put it in gear. I linked it through the end of last season by giving it a shot of fuel in neutral. Then it would run fine after a tiny stumble. Now it stalls even when i try to give it gas in neutral. 3 or 4 times of trying to give it gas in neutral, the engine will rev up. Then i can once again put it in gear and the boat runs. Do you think that would be a fuel pump issue or an injector issue?? And i assume you backed out the two mounting screws in this vid

So are you saying it should be a steady stream of gas?

I have a evinrude 150hp not getting fuel but I do have spark, any tips.

Boat turned off at lake and doesn’t turn back on . I did this no fuel leaking . Can it be the internal fuel pump 115 Yamaha 4 stroke ‘2015

Hey man i got a 1998 yamaha 130 v 2 stroke and i have change the pump, rebuild carbs , change gas , filters but still everytime i turn it on , runs for 1 min then turns off

2002 mercury 225 efi motor at wot only goes 7 knots

Every 3 years? I've got 4.5 yrs on the ones on my '96 225. There's a hot rod machine shop that makes blank off plates for them, at least for the OX-66 versions and then you use an automotive fuel pump mounted off engine.

My 50 ho mercury 4 stroke will run on starting fluid, will not run??? Thanks

Hey Carlos, I have a Yamaha ox66 225 2 stroke and the only problem I've been having repeatedly is surging. It keeps speeding up and slowing down. Any ideas? Thanks..

Hey Carlos I have a 200 HP 03 Saltwater series II 200 HP I am not getting any fuel sucked up into the motor it’s been sitting for 15 years what do you think it could be ? I have e two of those fuel pumps you showed one on top on on bottom .

Have a 2014 f70a and it will run fine for a while and then just die and never run again. Each time i start it, it fires and then immediately dies. The primer bulb is soft but you can hear gas moving in it. Using this trick the gas comes out of the screw hole around the loosened screw. Hoping replacing this works out

I have a Yamaha vmax 150 2007 2 stroke. The first start of the day (cold start) is rough. Even with choke it doesn’t want to turn over. I wait 10mins after and it fires up. Good for rest of the day. Any suggestions on the first start of the day? Much appreciated!

Need your help… This is a copy and paste message I wrote in an outboard forums. Just bought my first boat and owner said it sat for 6 years. its a 2000 mercury 90hp engine outboard. Before selling he took it to a mechanic who cleaned out the carbs and pistons. The mechanic thought he cleaned out the gas tank to empty but accidentally left 10 gallons in there, I filled up the rest so 20 gallons were in the gas tank. there was still 10 gallons with 6 year old gas. I ran the boat for 1 day on the water using my big motor for about 30 minutes before switching to my kicker. I then flushed out the gas and cleaned out the tank and put new gas... With the OLD GAS at full throttle my RPM's were at 3,200 @ 25 MPH. it would run for about a solid 30 seconds then start dropping to 3,000 and back up to 3,200 RPMs. This would repeat forever untill I drop RPMS a bit to under 3,000 RPMs and the issue stopped. With the NEW GAS it runs at 4,000 RPMS @ 30 MPH and after about a solid 30 seconds starts doing the same exact issue. Drops to 3,800 or so and back up. It will do this until i drop the speed. I cannot attach the video but I do not think this is a issue with Old gas causing the CARB to be clogged because Right when i got on the water it started doing it. and if the person cleaned out the carbs or other stuff it wouldnt be consistant. What else can i check without spending hundreds of dollars on a mechanic! PLEASE HELP!!! I checked spark plugs, gas line, ignition coil, everything’s good. I unscrewed fuel pump and it looks good but how do I know if it’s bad?

How would I know what year my yahmi 200 etxp 6g6 755714 is from. It's on a 81 G.W 24 offshore.

Can these go bad without leaking externally? My '06 yama150txr started & idled perfect after sitting 2 years (cancer sucks lol). Tied to dock and shut it off. Never ran again. It'll run on starting fluid, and one single time it actually started on starter fluid and then idled perfectly on its own fuel for about 30 seconds before I shut it off. I tried starting again, and it won't run without starting fluid. I'm not exactly sure where to go from here. Is there any other way of testing them, or does it sound like another issue altogether?

Can the fuel pump turn it on and still keep it running? Under load it turns off df140 2003...i just ordered a fuel filter for it

Hello there @ReelTeaseFishing. I have a 30 hp 2 stroke , 3 cylinder yamaha DMO. I start her up, let her sit in idle a couple of mins till i get my spearfishing gear in the boat and she runs great, no misfiring, full power, medium power untill i get to my spot and i slow down to anchor and then she shuts down. I pull the cord, she starts for a brief moment and then dies again. I ve inspected the fuel filter and lines ( no opstructions of fuel flow), but i cant do the low pressure fuel pump test you ve showed because the pump is connected to the middle carb. I took the pump of, both membranes and metal valves look to be in good condition, no junk, no tears. Recently all 3carbs have been cleaned, they re spotless. Also checked the plugs, spark is there. Any suggestions??

I. Have a 125 mercury 1985 and I am having trouble with starting no gasoline in the carburetors! I don’t know what to doo

1995 Yamaha 130 2 stroke. Bogging under load.. around 1500-2000k rpm. If you power thru the bog she will run wfo 5600 rpm’s with a slight miss you can hear. All plugs look the same.. new plugs new after market coil packs. 4 micron water fuel separator and a 10 micron after that and the factory water fuel separator on engine.. boat had 98 hours on it when I got it from my uncle January 2023 and now has 250. Could this be a fuel pump issue? I only run non ethanol fuel. It’s oil injected still.

Greetings my dear friend.. There is a 50 hp thatsu engine. 3 injectors are intact, the brain is intact, the fuel pump is working... but I think there is no fuel reaching the pistons. It works when I spray brake lining spray inside. I am a mechanical technician myself. Apart from the 3 injectors of the engine, there are also injectors inside the compartment called the log, I think they adjust the air and gasoline mixture. Could it be one of these? What is your advice? I wish you a good day... From Tuzla, Istanbul Greetings... Gasoline reaches the injectors. In addition to the fuel pump, there is also a pressure box that pushes the fuel forward.

I have 200hp 2 stroke but now they’re lose in the engine torque

Gas is dripping from the block when I press the primer bulb

Bro help please my primer won’t get hard

High pressure fuel pump

Mine is bogging down when i put a load on my 2001 mercury 125 2stroke