How To Diagnose A Boat's Outboard Fuel System With Carburetor Rebuild - Yamaha

[@slagletoby]

For the readers… When rebuilding carbs, especially when you have synchronized carburetors inline, it’s very important to set the float height. When setting the float adjuster screw for many types of Yamaha outboard carbs, the screw that holds the float pin in place is your float height adjuster. The more you tighten the screw, the higher the float bowl raises. Use your dial calipers or millimeter ruler and set the float bowl height correctly per the OEM manual, it’s critical, and don’t forget to add a drop of lock-tight to the set screw threads and let it dry. If you have one carb flooding, and one carb flowing too slow, your engine will never run correctly no matter how clean the carbs are. Always take this into account…. “It’s more difficult to make outboard carbs perform correctly at idle and low speed than they are to run at wide open throttle”. Make sure you have no air leaks, use fresh fuel, isolate your fresh carb rebuild by using a portable fuel tank until you know your motor runs perfect, then connect the motor’s fuel source to the built-in fuel tank on your boat. Watch more carb vids too, there’s more detailed vids that highlight the importance of all the tiny orifices within carbs, how to look for them as well as cleaning them. Keep your work area well ventilated and be safe.

[@rubenduber2226]

I'm having a lean sneaz at idle any suggestions

[@ericcope8216]

I know is an older reply but I have a question, you are saying that the screw that secures the float pin down to the body of the carb shouldn't necessary be tightened all the way down? I was under the impression that the screw just holds the pin to the body allowing for a secure pivot point? Please advise.

[@slagletoby]

@@ericcope8216 Yes you will want to tighten the float set screws all the way. The shop manual should have specific illustrations showing each step. The tab between the float and the float set screws is typically a thin metal material and can be slightly bent up or down to achieve the correct float height. Be gentle in this process, and have a micrometer handy to check for the correct float height measurement. Start by installing the float and float needle valve, tighten the set screws all the way, and be sure of correct installation. Then hold each barb upside down, and check to see if the float height is obviously different for each carb. If one float bowl sits too high or too low, this can cause the carbs to be out of sync at idle to low speed. This is just one of the variables within the carb system.

[@ericcope8216]

@@slagletoby Understood, thank you for the reply.

[@slagletoby]

@@ericcope8216 I may have been incorrect with my response. My bad. Each manufacture is different. Some carbs you can slightly bend the tab, some you set the height via set screw.

[@southatlantagaragedoors6515]

That poor little impeller didn't have a chance. i can just smell his little fins burning off

[@bblod4896]

Yep, I was thinking the same thing. 😢

[@BillhornA]

Many thanks for this video! I was able to tear down the carbs (Yamaha 60 HP two-stroke) , clean them and re-install them without dropping anything into the water as well. It really helped to know what to expect. All the best!

[@MotorboatToo]

3 things... I hope he tightened that jam nut on the linkage and secondly, I really hope he replaced the partially melted water pump impeller. Lastly, for anyone watching this for a guide... Most of the multi carb outboard 2 stroke engines have numbers on them to identify the style of carb, and a specific position or order they need to be installed. The reason is, there are specific jet sizes according to the position of each carb for better control of fuel/lubrication to the engine. Call it, "carb tuning" to better improve the performance and efficiency of the engine. You could cause internal damage if you don't follow the correct rebuild procedure and install everything back in it's original position. Just be mindful of the process you would use to rebuild the carbs and be organized. It's not very difficult.

[@talktodale]

Thank you so much! I am going to tackle this job tomorrow on a Yamaha 50 outboard. Now I feel confident for the review. Thank you again.

[@rebar4216]

thanks dude I am about to tackle that project and your video makes it seem less intimidating

[@jamesgregory2962]

FYI that "sensor" you removed from the center carb is actually the enrichment plunger called the "prime start assembly". This automatically enriches the center carb only for cold starts. Thanks for the video though. I am just learning about these old beasts. I like that you removed the oil injection. Great idea!

[@twistedgarage4139]

Yah the plunger works good after first startup. I still have to turn the red switch to full rich for 1st startup. As for the oil injection im actually thinking of putting it back on. Im starting to go to bigger lakes which require a full tank and its kind of a guessing game when mixing at the pump.

[@brucepeters5100]

@@twistedgarage4139 so what I do is look at how many liters of fuel I've added from the pump reading and add oil according

[@twistedgarage4139]

@@brucepeters5100 and theres enough room left for you to pour the oil in? Iv never tried, just assumed it would be too full i guess.

[@brucepeters5100]

@@twistedgarage4139 I don't fill mine right to the top so there is room to add the oil.

[@jordanlewis7977]

I also put oil first then gas. Mixes better

[@earlcharles7463]

Well informative. Great video. No time wasted. Straight to the point.

[@rickpaudert7012]

I had the same problem on my 40 hp Yamaha, ran good, then would stall, did the same rebuild on carbs as you, problem presisted. I’m currently changing out all fittings and hoses between tank and carbs , all gas lines also. I’m hoping I had a small gap somewhere and was sucking air slightly reducing the pressure for fuel to carbs. Hope you got yours fixed. Happy boating!

[@ivanmorelos3795]

I have 1985 40hp yamaha..whats the rebuilt kit part num..and where do you get it?

[@traviskelly5480]

Same problem on my 40 yammy. Did you find your problem

[@paulmcguire6366]

Just a suggestion....... On a boat with a built in fuel tank and a motor of size that is bolted (not clamped) to the transom I suggest the following. Do away with any form of fuel quick disconnects to motor as there is no reason for it......not swapping motor from boat to boat or transporting tank for filling. The O-rings in these disconnects are prone to failure allowing air to be drawn into fuel system. The leak will be subtle and hard to visually detect. It will initially show up as a motor that falters under high throttle conditions. The high draw of the fuel pump will bring the quick disconnect leak problem to the surface. Great video on trouble shooting the fuel system and servicing the carbs.....they certainly needed attention in this case.

[@MrGreatnessHimself]

Good to know

[@ferllyr]

Good video. I followed it to do the carbs on my 40 hp. One thing I could not figure out was what to do with the 3 little plastic caps. After I finished, I realized they were supposed to be put on the top of the needle valves. I reopened each carb and installed them.

[@kevinspell1054]

So is the next video on replacing the impeller or the head?

[@rudedog1347]

Now please make a vid of impeller replacement because you just killed yours, great vid but no water on start up is definitely not good.

[@dyizhere]

Are you running the motor without water in the garage? That'll sure put a hurting on the water pump. Great video.

[@michaelcosman3698]

Lol, that’s what I was thinking!!

[@XCaptaintravis]

And for our next video, how to replace a water pump on a Yamaha Outboard xD All seriousness good tutorial

[@jamestoovey4668]

😂😂

[@hectorsarraga2475]

Nice video, gave me a good idea on how to check the carbs myself and save some money

[@marcoaurelio9879]

good afternoon, please which initial adjustment of the carburettor air bolts, thank you.

[@williamriley2528]

I bet it tells you in the $20 Clymer Yamaha Repair Manual...!

[@williamriley2528]

@pencil whip Better check those 2 adjustable needle/seat screws in the top left of the photo above buddy...

[@dimitrisstavrou4881]

Hi...i have 115hp v4 yamaha 2 stroke...I have a problem... you have a hard time starting it... but i throw sprey after that it's fine. Maybe I need a new fuel pump or an advance adjustment???

[@juniorjr7026]

Hello I have the same engine , one question do you know the How many compression PSI this need to give ?

[@135-j]

AtleSt 100 In my opinion

[@ryanbaumber7643]

Do you have a link to the video where you adjust the front throttle controls?

[@scottanderson7241]

setting the float level is very important 15mm on my 50hp.

[@Koolbreeze25]

I want to make sure I'm actually addressing the issue. My 1990 Y175 2 stroke is beginning to bog on hole shot so it could be a number of things. What's the proper order to address? I'm thinking fuel quality-lines-filters-spark-coils-set up etc... Sound right?

[@MaximusD180]

Did you find anything in the carbs that was restricting the fuel flow?

[@johnmac403]

Hi I watched your video, it's very enlightening. I have a fuel problem with my motrin getting fuel to the carburetor, have had the carbs rebuilt also but no gas is going into the chamber therefore it won't start. What can be the fault for this problem?

[@broncohuntly_7269]

I have the same motor here I'm working on 40hp Yamaha, what would cause it to not want too idle stalls out and makes a grinding noise. runs fine going across lake give it throttle?

[@dioulisdna1255]

nice work I have a question just because we have the same Yamaha 90hp engine , has ever happened to leak gas from the carburetor after the trip is sitting up (45 degree angel) on trailer ?

[@twistedgarage4139]

Iv found some fuel in the airbox before so possibly.

[@AndrewDougZA]

I have this issue. Can you recommend a solution?

[@partyoffive12345]

How long do you generally let the carb parts soak in the chemicals?

[@dedegias]

Nice video!I have a yamaha 40 veol 2stroke 3 cylinder.During cleaning the carburators i saw that in the central carburator the pilot jet has different number (smaller) than the other two. Is that normaly? I appreciate every answer!

[@twistedgarage4139]

Yamaha has a good parts website with diagrams of each engine with part numbers. Id start there

[@irvingguerrero6052]

Excellent video. Thank you for sharing your knowledge

[@broncohuntly_7269]

water impeller pee hole was plugged. have it spraying water now?

[@dukemanvillle]

Nice video.. I have the 2008 Yamaha 50 TLR and I just rebuilt the carbs. I had to drill out the brass plugs to get to the pilot screws.. I replaced them with the new ones in the kit but my manual doesn't say what the setting would be for each carb. does anyone know how many turns I should back them out for each carb? Thanks !

[@joshpruitt1180]

1 1/8 to 1 3/8

[@dukemanvillle]

@@joshpruitt1180 thanks !

[@steelecooper4140]

Thats my motor, I learned a lot. Thanks

[@lucbernard3057]

Did the carb rebuild solve your issue? I am having similar issue with a 2001 60hp 2 stroke. Did you install carb kits (new parts) or just clean?

[@manbearpig8691]

Great video, gave thumbs up. By any chance would you know if the carb set up on my 1991 Yamaha Pro 60 would be similar? It is also a 3 cylinder, 2 stroke. It hasn't been started in 10 years so I'd think the carbs are gummed up.

[@27slobass]

What's the red lever on the side of the middle carb?

[@kobe2544able]

God bless you love you from Jerusalem the capital of Israel You make money for me today 👍👍👍

[@135-j]

What do you mean the jet has a bigger hole on one side and that’s going to be your topside It’ll only go in and fully seat one way or do u mean something else by that Around 12mins 5 second mark

[@yoyimarti2864]

Great step by step explanations👍👍👍

[@dadnova1]

Check the fuel line, I had an issue, went to a boat shop, he seen the gray line and just cut it with a knife, the inside looked like it was full of cornflakes. The engine would start, would run but at WOT it would die or bog down.

[@aaronwagner8904]

Fuel line to the motor? Or old gray fuel lines running to from fuel pump to carbs? I have similar issues. Runs great until 4500 rpm, then lays down and the tach bounces. 1987 pro50lh.

[@elvisrockselvis4681]

My 9.9 yamaha i have fuel pump to.i got fuel coming out pump but not going in carb. I cant blow air in carb it's really hard. Is that normal? I cleaned carb good twice line is clear.is it supposed to be hard to blow in carb? Thank you

[@PackerTN]

What size fuel lines are on these 70tlrb?

[@kenawtry5056]

I have an 89 Pro V 150 2 stroke. It idles great but when I get on plane, it acts like it’s starving for fuel. Is there a screen at the bottom of the line into the tank that may be clogged?

[@twistedgarage4139]

I had a similar issue but it was actually running too rich. Mine was the fuel pump, diaphram was leaking internally and just dumping fuel into the engine causing it to bog down when trying to get on plane. Been fine since.

[@timjohnun4297]

What was the problem with the oil injection? in my experience they rarely fail...

[@yunierperez8987]

But when they do you get a blown engine

[@timjohnun4297]

@@yunierperez8987 same as if the oil pump fails in a 4 stroke, right? 🤷‍♂️

[@yunierperez8987]

@@timjohnun4297 I guess but doing premix you wont have that problem.

[@James-dp4ye]

People say bad things about oil injection with no real experience! They just pass around bad advice like they know what they are talking about! " But when they do you get a blown engine "! 🤦‍♂️

[@michaelgrant7062]

@@James-dp4ye Japanese engines have a metal gear driven oil pump like a car. Unlike the American outboard oil pump that are plastic vacuum operated. When was the last time a oil pump has stopped working in your car?. Never for me

[@richardwolske2015]

I always inspect every piece I take out to get a more positive idea just what the problem was , float , plugged jet , air adjustments maybe off . Every little bit of information can give you some piece of mind . Did you have water on the pump ? 🤔alway need to have water on the pump . Rubber on stainless without water is bad for the impeller.

[@Catnot1]

Dog toenail clippers work great to cut off zip ties been a mechanic 54 years

[@hardbodymini]

No float adjustment?

[@reginawakon3152]

I'm have problem with fuel flow from the Fuel container to the Engine.

[@michaeltackett6943]

What part number did you get for the 3 card rebuild kit?

[@twistedgarage4139]

I couldnt find a complete kit, i just got on yamahas website and found all the part numbers then ordered from different places

[@davidtownsendSTL]

What is your oil to gas ratio? I have same motor

[@edgewatersbestguitarist1524]

Those Yamaha carbs are funny, the jets they use for the motors that have oil injection idle at 200:1 and advance as the RPM's increase. Make sure you've got your proper jets for those carbs or it'll just never sound "quite right". I'd go 100:1 for that 3cyl 85. Coming from an East coast FL outboard mechanic

[@harveynewman4333]

did you sync the 3 carbs,after installing them?

[@twistedgarage4139]

Yah, if the motor is stock you should be good with the stock setting, which its been a while but i think its 1.5 turns out. This motor was rebuilt so im about 3 turns out on all 3. Just do it by ear. Kind of a pain but only took a few mins on the lake.

[@harveynewman4333]

@@twistedgarage4139 no,what i mean is syncronizing the throttle plates after removing the carbs. they usually never are correct after removing them for repairs. the throttle plates are not set the same because of the reinstalling of the carbs.

[@twistedgarage4139]

@@harveynewman4333 ah i see what your saying. Well these intakes dont have vac ports. I followed the procedure straight out of the shop manual. Remove intake, rotate idle screw till ports are closed. Losen middle and upper lever screw to release slack. At this point all 3 port should be closed. Then adjust idle screw till you get your desired idle. Honestly on these yamahas, you set everything per the shop manual. If it dont run right you have some problem

[@joshpruitt1180]

What's the float height spec?

[@FishNFoolLures]

Yah The next video will be how to change the impeller because you ran it without any water. lol

[@leop1193]

Didn’t connect it to water bad idea

[@yamahass66]

Did it get better after this?

[@michaelferguson2955]

Next video.... How to replace water pump

[@timjohnun4297]

yep lol

[@carlosperez473cp]

What fuel/oil ratio did you use after deleting Oiler?

[@twistedgarage4139]

50-1

[@twistedgarage4139]

Well atleast on mine theres only a low oil sensor in the resevoir. But if theres a blockages in the lines or the pump goes bad youll never know and ruin ur engine. Its a pain but i feel better having it off

[@JoshSmith-wo7zw]

I would also make it a point to replace your fuel lines/hoses every 6 to 8 years as Ethanol causes more issues than it solves. I'll just leave it at that. It will attack and break down just about everything. Fuel lines can either collapse internally due to Ethanol eating away at them or you can have small pieces of rubber and plastic break off and basically find their way into your carburetors and clogg up the jets. Preventing your engine from running properly. You also should add a water separator to your outboard if you don't already have one. Because Ethanol also loves moisture.

[@FishNFoolLures]

Nobody with half a brain runs ethanol fuel

[@icefisher1171]

Or use ethanol free fuel.

[@JoshSmith-wo7zw]

@@icefisher1171 thats assuming you can find it in your state. If your state doesn't have any large scsle fsrmers chances are you won't be that lucky.

[@prohomevideos]

@@JoshSmith-wo7zw My Wal-mart carries ethanol free, love it.

[@brucepeters5100]

How did it run. Did you have any issues since the service?

[@twistedgarage4139]

I took it out a couple weeks ago after it had sat for a few months and it stumbled when i had the plunger in auto choke. I switched it to run and it was fine so i tried it back on auto and it was good. I then took it out today with no issues in auto mode. I think that plunger can be finiky. If it happens again i may just replace it.

[@marcoaurelio9879]

boa noite, parabens, por favor meu motor é yamaha 60 2 tempos, voçe pode me fornecer ou gravar um video para o canal ensinado a regular e equalizar os carburados do yamaha 60 hp 2 tempos, desde ja agradeço.

[@alanogden5350]

What is the fuel line size at carbs, ID

[@williamriley2528]

All outboards use 5/16" (or 8 mm) marine certified fuel line

[@highlandbob7029]

@@williamriley2528 You use 3/8" for the larger motors, usually 125hp and up, V4s and V6s. The 3/8" hose will work fine on the smaller outboards, but not vice versa.

[@dennisharrison4744]

Hope water was on it guy just got my 85hp yamaha from started it day i bought the boat just a second geus what water pump went out

[@abc123hshdhd8w]

When you say the main jet has a bigger hole on top side. Doesn't that mean the hole goes up through the carb or on top while you're rebuilding it

[@troytorman1131]

Have you ever run into a problem with that roller on the middle carb butterfly hanging up on the throttle arm accelerator cam? I just did my carbs and same deal, the motor idled a little high. I was able to back that idle adjustment screw out all the way and it still ran perfectly fine. I shortened the arm length to the control and it backed it down just a bit more, but the roller doesn’t really wanna get up and over the hump on the cam. All are in decent shape and well greased. I think I have it dialed it but haven’t run it in the water yet with proper back pressure. Just curious if you’ve ever run into this, cause I can’t find it online anywhere. Also, be careful with the accelerator level rod and popping it off with that much force and a screwdriver. Try and use even pressure on all the joints, or at least top and bottom, I’ve broken one taking it off with less force than that! Luckily I had a spare from a parts motor layin around.....

[@antonioprado8068]

I saw no diagnosis. To diagnosis the pump you have to remove it, use a mighty vacuum and check out and inlet pressure and be within spec. Then move on to the carbs

[@streetbobheaven4068]

Is the water on ?? If not that impeller is toast….

[@carlosperez473cp]

How do you adjust float?

[@williamriley2528]

Carb upside down, float level with carb bowl base surface.

[@markotto3334]

Nice video. Thanks for that great info.

[@lighthouse7ry]

And can be that gray fuel line as well They are no good and they will break up on you

[@milosfilar4866]

Where is connection to water?

[@AS-pq3hu]

Many thanks for this video

[@dannyharris2581]

Great thanks for the in put

[@Bishbashbosh67]

Fixed the carb issue but then had to change a burnt up impellor, Alway have some water flowing through your impellor 🙄

[@HayPOWER-PR]

Thank you 😊

[@MrJovolto]

Muito bom vídeo. Tenho um motor Yamaha 40hp 3 cil. e vou fazer a manutenção dos carburadores.

[@fernandosoto994]

You didn’t run with water??????, 😮

[@brandonhaupt7633]

Might wanna hook some water to it next time

[@andre2679]

Thanks for the video

[@kevinalbers1084]

You never addressed the correct setting for the Primestart

[@delstep2255]

Thanks.

[@mdk5112]

Good video

[@feriazhariazhari8333]

Harga Yamaha 85 2 tak

[@mx8866]

Fuel pump diaphragm

[@Salww1]

Amazing

[@josem.r.fialho6561]

perfect

[@gabeval9350]

Why are you running you're motor indoors? You will have a problem on the water. Your motor isn't gonna piss cuz the impeller is burnt up from not running water through when you crank it in the garage.

[@reimundomartina9117]

Master

[@juangonzalez8734]

Why would you run your engine without water.? That water pump is tosted....🤣

[@dailystruggle2762]

now impeller is fucked...

[@bingowhoisthisguy4574]

got lucky

[@adrienbastarache8096]

Good video,but loose the funky music,

[@granddesignmomentum4374]

Anything you may have accomplished there was totally canceled out by the ignorance exhibited running an outboard without a water supply. Now the time your out on that lake you get hot alarm if hooked up if not overhaul powerhead. It only takes that impeller 6 seconds and it's toast.

[@trngpl]

Great step by step explanations👍👍👍