Yamaha Prime Start diagnosis

This video goes through removing, diagnosing and servicing the Prime Start system from a Yamaha outboard motor.
For outboard repair information, checkout my website: outboard.dangarmarine.com/guide
If you are enjoying this channel, please consider making a donation to www.paypal.me/dangarstu or become a Patreon of Dangar Marine at / dangarmarine
T-shirts and other merchandise available at teespring.com/stores/dangar-m...
Common items used in these videos are available from my Amazon store at www.amazon.com/shop/dangarmarine
Dangar Marine is proudly sponsored by MarineEngine.com. MarineEngine.com supplies a wide variety of spare parts for many brands of outboard motors. If you are in the US, be sure to check out their online store www.marineengine.com/
All music available at soundscloud.com/dangarstu

[@jillveefkind2847]

Just wanted to say thank you. I defiantly learned how it works. Whatever happen to a simple manual choke. Some engineer must of had a dream! Thanks again.

[@kevinkleinhenz6511]

I hate not having a key activated manual choke on my 1993 Yamaha 70. These auto chokes stink.

[@tcap7917]

I like that your never in a rush to just put new parts on and hope for the best.

[@steveaulick5863]

I have been following your blog and have found it very helpful. My yamaha 50hp 2 stroke was over heating and , with your help, I was able to find the problem and fix it. I flushed the engine with muriatic acid and that helped but I ended up pulling the head and cleaning the water jackets manually.

[@jasonkizel5665]

I love you! 98 Yamaha 50 EJRW and the manual doesn’t explain enough for me. You are the Man ! Cheers Mate!

[@patricklydon6935]

Nicely done! Thanks for taking the time to explain how this system functions.

[@larryrobinson7492]

Excellent job showing how that system works, Thanks, I never knew they had that system until I was trying to diag a cold start problem for a friend/customer. I found the line off at the engine so that may be all that was wrong but now (thanks to you), I know how to test it for sure.

[@jarlebrve6576]

Informative, spot on and honest. You make great videos, illustrations are simple and get's the point across every time.Always looking forward to the next one.

[@DangarMarine]

Thanks Jarle, I thought it was important to be honest about how effective this fix was. The clues were there, I was just too keen to make the vid...

[@hookempescadosaustin4111]

Another awesome video.....helped me diagnose prime start issue on my 2008 Yamaha 50TLR. Much better than reading the Yamaha bulletin boards! Thx again!

[@taatibarao3764]

Man i love your video very much i got the same problem with my yahma 90hp....thanks for taking your time for sharing your skills on marine outboard engines... Cant wait for your next tutorial video...god bless

[@johnmaxwell3302]

Excellent video and description, Stewart. The best how-to I have seen.

[@larryrobins1944]

Great Job, Thank you for taking the time to make this.

[@stevecushman2280]

Love your videos! Extremely informative. Keep them coming.

[@SharpByCoop]

I have a 20hp Yam which runs fine but lately started to load up at idle and stalls. I checked the (2) blue wires leading to it and NO voltage whatsoever, even with the ign key depressed. Your vid shows me it's *ON* all the time. Tomorrow I will be more productive figuring out the open wiring, and allowing it to close. Thank you!

[@jasonkolacinski6065]

Very detailed video! Great job! I was looking into this system today as my 90tlrc has made up its own mind as to when it wants to start.

[@a1marineshop189]

Really enjoyed this video, having carburettor problems with an identical engine, that has been submerged in seawater and then cleaned up. Well done!

[@DangarMarine]

Thanks mate, glad you liked the vid. :)

[@ThatOldMan2112]

Well done, concise video. You are very good at explaining the how and why of what you are doing. It's a bummer that things don't go smoothly all the time, but honestly, I think it helps people more when they don't. You just solved the problem and kept moving - so when we run into the same problem, and you know we will, we have some idea about how to solve it (and the misses is impressed that her man can get things done - thanks mate). I was looking up help on a steering install to help a buddy and stumbled across your channel. Think I have watched about 7-8 so far and now have a couple planned projects of my own. (cleaning the steering shaft on my stick steer being the first) Definitely subscribing!

[@dedegias]

Hello from Greece,nice job!

[@Myotis05]

Super helpful. Can't find any other prime start videos!!!! Thank you!

[@DangarMarine]

You're so welcome!

[@michaelboykin9881]

Great video. Answers all my questions. Knowledgeable and uses common language. Thank you

[@DangarMarine]

Thanks mate, glad it helped you.

[@keithduffield5239]

Thank you so much. Lent my boat to my son and the Red levers were in the open position as I had just serviced the carbs. What a disaster, boat was terrible and used nearly 100L of fuel in the little ride they tried to go on. Now I understand how that circuit works. I thought my actuators were faulty as I tested them with a battery and nothing happenned.

[@barryjohns1965]

Great video. I am having an issue with cold starting a Yamaha 115 V4. I am going to look at this prime system for sure. I noticed if I coak each plug in fuel and put them in then the motor starts fine. then it will start like a champ. After it sits a while I have to do the same thing. Runs great after it starts. Anyway. Thank you for the video. I subscribed for sure.

[@edgewatersbestguitarist1524]

really glad to know that prime start isn't supposed to "click" open/closed when its activated like a choke mechanism. thanks for all the explanations! cheers

[@DangarMarine]

Yep, these ones are completely silent.

[@WillsGarage91]

Excellent as usual. I've always wondered how that system works, have worked on a few of them but not recently.

[@DangarMarine]

Thanks Will, glad the video helped! :)

[@jamesvonrohr5212]

This is an excellent video. It really helped me get my Yamaha motor going again.

[@DangarMarine]

Glad it helped

[@deonsmit819]

love your work friend, thx for sharing your knowledge

[@douglasmontgomery6315]

Dangar, my background is electronics. A few things: 1. When measuring resistance, you should not be touching the leads with your body (fingers)...can change results. 2. The internal lead resistance is spot on. However, your Fluke multimeter has a function to zero that out..no math needed :). It's the REL button on the meter. Switch meter to proper resistance scale you will be using. Connect leads together (I typically use alligator clip lead ends)...when meter reading settles, hit the REL button. That will now zero meter (taking into consideration the resistance of leads) :) Thanks for the video

[@DangarMarine]

Hey Douglas, thanks for the tips, will certainly bare that all in mind next time I'm doing these types of tests. :)

[@burakr.7436]

Very good channel for outboard lovers.

[@CoolKD2005]

Thank you sir for the information I needed to diagnose.

[@relocationorlando]

Thanks for the info, this is my first outboard, have an extensive background in auto and the video you produced left nothing out and I quickly picked up.

[@daimlerblanco3752]

I just love all his videos he is so really talented on what he does

[@stevenlove200]

Totally agree...he does an excellent job, easy to follow and understand!

[@charithpadmajithpalihaderu5253]

Absolutely im a marine tech and i have learned a lot from him 💗💪

[@GeorgeLanivich]

Awesome video. I have the same engine with problems all season. I have cleaned out all the carburetors and it will run fine and a week or two later it’ll start running lousy again. Now it simply won’t start. I will throw some starting fluid in today to see if that helps to get it going and stays running at this point being that all the carbs are clean just not starting. I love your videos!

[@DangarMarine]

Thanks mate. Take a look at things like the fuel lines. If they are perishing you can clean the carbs and then more junk will come straight through next time you run it.

[@colineddy1124]

Very good video thank you. I have cold start probs on my Yamaha 90A so this is ideal.....

[@jyeames]

Outstanding explanation. I became your newest subscriber! Thank!

[@DangarMarine]

Welcome aboard!

[@versatec1]

Excellent video as is your default standard...Thanks😊👍

[@DangarMarine]

Thanks mate, glad you like it. :)

[@johnchandler2870]

Thanks for this video, its the same issue I having , gives me a lot better clue what to look for.

[@DangarMarine]

You're welcome!

[@jimmcmullen2526]

Great info indeed! I just bought a Y90 and I was looking for the choke solenoid...LOL.

[@4X1000]

Excellent video Stuart! Everything explained in order and in an easy, understandable way. I am about to go into fight with an old 50hp Johnson, I do not know yet if it gonna be a fuel or ignition problem, we'll see about that =) Again thanks for your videos!

[@DangarMarine]

You're welcome. Good luck with the Johnson!

[@MrMatthewkirby]

Bad starting, checked everything and it was working. Decided to strip that carb down one more time and found a small hole from the main fuel bowl into the thin fuel bowl to the side was blocked, this then feeds the prime start. Cleared it out and it started without using easy start. Worth checking.

[@danielmartin2463]

Hey Stuart, great video again mate! I always look forward to seeing them! Have you ever dropped anything in the water working on a boat? Your Channel is doing great mate! Looking forward to your next video! Cheers

[@DangarMarine]

Hey Dan, great to hear from you. Oh yeah, I'm always dropping things in the water which is why I try to do most of the work in the shop! ;)

[@danielmartin2463]

+Dangar Marine likewise mate, good to hear from you. Ahahahahaha yeah I'm the same, I even drop stuff off my bench and loose it on the ground. I have a habit of dropping the super small metering springs out of carburettors. Take care mate, all the best!!

[@wg8847]

The best i have ever seen.. Wish he was my mechanic..

[@MrThumper1440]

If you’re going to wish for something, wish you didn’t need a mechanic! LOL

[@brianrush7478]

Absolutely the best video Thank you. Can I come live in your shop for aa few months?

[@bblod4896]

I had the same exact issue. The way I start mine is move the red tab to emergency, the engine starts up quickly and then I set it back to normal. So, if the slots just bypass the electric valve, perhaps it's not retracting enough to let the fuel in? I see you posted the video 7 years ago thanks for keeping it up here.

[@MrMatthewkirby]

Problem solved! Check prime start was working and all doing as it should. Noticed the prime start has its own fuel bowl next to the main one , there’s a tiny hole from the main bowl to feed it, it was blocked! All sorted!

[@DangarMarine]

Nice work!

[@Mike-ef5lj]

Dangar, thank you for the video. I just took my prime start mech apart and the diaphragm connected to the cover plate with the red open, close, normal "valve" had fuel behind it. I know, from your video that it should be sealed and only allow pressure from the crankcase. It's not torn but maybe has a tiny hole or was loose. Would this be a problem? Thank you

[@sherriturner4226]

Great video! How does this system work on a manual start motor?

[@ryanschreck9722]

Very informative, thank you! Question though, if the valve inside is set wrong, or comes loose, would that cause problems if it was set in Normal mode? I’m chasing a fuel starvation problem and the only I noticed on mine was that the screw was loose that holds that metal valve in place. I didn’t know if that diaphram was only used in open mode and bypassed in normal mode since the other carbs don’t have one

[@MikeRobertsmarketing]

Cheers mate!

[@dogsgonewildts]

great video. but what position should this run in. normal, open, or close?

[@petter8205]

Hi! Are you known with the primers on mercury 75(yamaha 80) 4 stroke? I have a really hard time starting it cold, and messured the voltage on the cables going to it and only got some millivolts when holding down the key. Are these going to have 12v?

[@nwitte8846]

Hi hopefully I'm not too late on this topic. I'm having the cold start problem with my 9.9. it's a 2000 model but I'm wondering if it's not a prime start and is the older choke style that you mentioned. The piece looks similar and is called 6g8-1410a-01-00 Any help would be greatly appreciated. Thanks

[@fabiansosa5318]

Always look forward to your videos every week mate.Great job once again. I'm after a service manual for my yamaha 30hp cv and was wondering if you know where I can find one preferably in the book form and not on cd?Look forward to your next video and would like to see one done on how to check and set the timing if an opportunity arises for you to do one. Cheers.

[@DangarMarine]

Hey Fabian. I've always bought them online and then printed them (Office Works have a great binding service I use). I get them from www.tradebit.com/G/manuals/18-outboard or readmanuals.com I've definitely got a timing video scheduled. So many to get through!

[@fabiansosa5318]

Cheers mate,will check them out.

[@hooklinetinker9680]

Great video. I've learned a lot from it, thank you. I have a 2000 Yamaha C70 2-stroke without oil injection. My problem is that it runs very rich with the fuel enrichment switch in the normal position. I've had to set it to the off position as it will otherwise smoke a lot, run rough at low speed and burn a hell of a lot of gas. Needless to mention it has a hard time starting when the temperature is cold. In which case I have open the valve to start, allow it to run a few seconds, then shut it off, close the valve and restart it. Most annoying. What does that sound like to you? I'm interested in your feedback. Thanks in advance, and keep the helpful videos coming. Ted Marshall Sanford, Florida, U.S.A.

[@steveb1307]

Hi Stuart, good video but I do not seem to be able to get out the valve that you appeared to have removed at the 7min:10 sec point. I need to remove it now because the reed valve is loose. Any advice on how to remove it? Thanks

[@Shareyourpositive]

I’m working on the identical engine now. I found a split diaphragm and replaced it. It will not start in normal position. It will start and run in emergency. After it is warm I will switch it to off and it will not run. The carbs are clean. Fresh fuel with new fuel filters. Al jets and holes are clean and free from trash. What would you suggest now? I have not tested the prime start and don’t think it is the problem since it will not run when warm.

[@marcoaurelio9879]

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

[@mackiebellott8975]

I’m having an odd issue with my Yamaha tlr70 2005 two stroke. I’ve changed out fuel pump, cleaned carb, spark plugs etc. oil pump is bypassed because I premix. When it runs it planes at about 31mph. After about 10 seconds it rockets up to 40 then sometimes goes back and forth as if one cylander is kicking on/ off. It starts right up and idles great. Compression is 125 across the board. What do you think could be the issue?

[@peterdonnelly154]

Hi, Yamaha 90 TLR, had to remove the oil tank to repair a leak, noticed the black ground wire to the prime start was dangling, connected it to the block and now the engine won't idle runs very rough. I was going to disconnect it later today and see if it runs back to normal if it does what might that tell me? THX

[@Silentroller93]

Can I add that prime start system to my 87 Yamaha? It looks like I can get a new set of carbs that has this system in it but where does the power wire go to exactly?

[@keithslade9379]

2000 c50tlry parts schematic does not show the o ring on the end of the shaft on the on off control lever. is the o ring replaceable or part of the shaft tip?

[@chrish7532]

This was VERY HELPFUL! You are fantastic!! Thanks for putting these up. Question for you: What do you think is the best brand outboard 150 HP for saltwater?

[@DangarMarine]

These days all the major brands make high-quality outboards. I personally feel the decision about which one to buy should mostly come down to who can give you the best after-sale support. This included things such as which dealer is closest to your home (or work), and which dealer has been the most helpful during the investigation phase as they are likely to also be the most helpful once you have bought the motor.

[@larspettersson6934]

Nice InstruktIon. Can the prime start effekt normal running? I have a problem that may engångs dont inkrese rpm over 1100. Notest that if i a move emergensi switch under running the rpm inkrese like normal under a short time.

[@gregl5649]

I'm having an issue where my outboard is starving and bogging when throttled. It is running fine in the emergency mode. I appear to be losing some fuel pressure in normal mode, but not in the emergency mode. Its doing my head in. Any suggestions?

[@JuanRamos-lz5ir]

Buen trabajo grasias Me gustó Estoy buscando un electric primer choke O el carburador para compralo

[@kyriakosver7997]

Hello, i have a yamaha 60F 2 stroke and i thing i have more consumption than normal, not only on its way, also at idle . The engine has also difficult cold start(starts only with the red valve enrichment) so i am planning to change the o-ring and the solenoid to the prime start. The boat is ok (weight distribution, normal weight e.t.c.) . What should i do so i dismiss the idea of the more consumption? in my plans are also to put a new carburetor repair kit. Thanks a lot!

[@MattyMiranda]

Hey mate great channel very well explained. I've got yamaha 40hp veto and if I close the prime start it red lever it runs ok but if I put it to normal or open it runs crab and eventually dies. Plus at full throttle it's got no power. What do you reckon.

[@DangarMarine]

I would start with a carburettor clean and go from there.

[@krzykamienski]

Hello, (sorry, I don't speak english...) Does enrichment also affect the start of a warm engine? Where does the blue cable come from? I have a problem that the warm engine (Yamaha autolube 40 TLRZ) will start if I turn the first spark-plug off. Earlier, I swam a long time about 1 yaer) with a broken one cable from enrichment. I fixed it. Now the colour of sparks is OK like milk coffee. Compression is 8,6 8,5 8,2 Bar. Help me please.

[@scottf.5472]

I see there is a depth adjustment on the solenoid. Its a threaded section than with change the depth of the valve. I think mine is bad because it maxes out the extension of the valve in less than a minute at 12v

[@BradG902]

love the duck transition <a href="#" class="seekto" data-time="105">1:45</a>

[@DangarMarine]

Thanks!

[@walkertonheights]

I can add a little info on this en richer device. I have a 1992 90HP and mine looks the same as the unit in the video. When 12 volts is first applied to the device it draws about 1 amp. after about 2 seconds this has dropped to 0.6 amps. Then after about 5 seconds it has dropped to about 0.4 amps. It stays at this current for a few minutes, then drops to about 0.2 amps, where it stays. The piston moves about 4 mm out when fully hot. All measurement where done at 70 degrees F, I expect if your temperature is different you would expect slightly different results. I could not measure ohms reliably even though I have a quality fluke multimeter. The device was about 60 degrees C once hot.

[@alexeygembik608]

Hi Stuart, you are the best! Thank you for that video. Can you please advise what can be other reasons for Yamaha 70hp does not cold start. Usually I tried six to ten times before it starts. But after a couple of seconds it stops again and than start normaly. Thank you

[@DangarMarine]

Hi mate. Normally a hard starting is either the prime start (or choke depending on the motor), but it can also be a blocked idle jet. If the motor is older then it can also be low compression or a problem with the reed valves if it is a two stroke.

[@TIA910]

I know its a comment for an old video but I have a question, is it normal in your opinion that during a cold start the rpm goes to 3500 for about 1min before getting to the correct idle speed? (Yamaha 40cv 2t 1991) Could it be a problem with the needle you tested? 🤔 thanks for the reply I follow every videos of yours and you are so good in detailed explanations!! Thanks from Italy

[@GUNPASSION]

Hi great video . I cant remember is it supposed to have an audible click sound when you press the key in to activate it ? Thanks .

[@DangarMarine]

No, it's not a moving solenoid.

[@samcanno7692]

Hi Stuart, Thanks for the informative video... I have a 60hp Yammie 2005 that is hard to start, when warm starts first go but when cold it takes 2-3 minutes of constant turning the motor. After reading the manual and watching the video I know see it not a traditional choke. The earlier yammie I had used to rely on pushing the key in for the choke i guess now thats controlled by the plunger pin thing. Do you think my problem would be the pin? Thanks

[@DangarMarine]

Hi Sam. It could well be that the prime start system is malfunctioning or perhaps that it needs a carburettor service. Also be sure to make sure the primer bulb on the fuel in is firm before trying to start the motor.

[@BigMkombe]

Hey Stu Great video, It seems you have a video for everything that has ever gone wrong with my outboard. BTW do you know where the blue wire connects inside the control box? mines dangling in thin air, after taking everything apart only to be working perfectly I'm suspecting thats the problem to my boat ramp woes. Does the Prime Start need 12V constant/acc or only on crank? Love ya work

[@DangarMarine]

Hi mate, glad to hear you've been finding the videos you need. Blue is normally trim up (green is trim down). Does the boat have electric trim? Prime Start gets continuous power as it takes a while to get up to temperature after it starts running and cranking has finished.

[@BigMkombe]

Hey Stu Thanks for the reply man, yeah its got trim, its a 90c with forward controls, ive got everything connected and working after buying the outboard and control box separately, although everything is connected and working, theres a dark blue wire with no where to call home, after seeing this video I assumed that could be the root to my choke issues, ill investigate further, another great excuse to drink beer during the week. have you got any Dangar Marine stickers yet?? Thanks heaps Love from Darwin.

[@msohel]

Hi would u please tell me why the carburetor starts pouring out fuel after I have reinstalled them. The float and the middles all new. I took them off again and reinstalled same thing. Please help. I have exactly same motor. I followed u same , can’t figure out what’s wrong. Motor starts up right way after I Installed every time. But starts flooding in few seconds of running.

[@GringoSF]

I have a motor just like when I decelerate it makes an explosion or two that can be good video this

[@marcinmichalak1769]

Hi Stuart I have cold starting problem with my Yamaha 75hp 1999 with fuel enrichment primer. Is a 703 Yamaha control box key switch suppose to have key push in to activate that primer? My 703 control box key switch is rigid just turn on or off key to start or turn off the engine. Is that correct key switch in that control box? I remember having a 40hp Mercury with push in key switch to active a primer. Thank you

[@DangarMarine]

These ones are always on when they are cold, they aren't a solenoid like the Mercury style you are describing.

[@TheAshlynn05]

Thanks for the video. Helped me determine how the system works and why i can't find the little blue wire for the enrichment valve. Several different schematics show it coming straight from the key switch, but this one hooked into the voltage regulator. Your explanation of how the system works means your "choke" with the key switch does nothing. Guess I have a set of carbs to pull and clean. And thanks to you, I'll be keeping an eye on those oil injection lines. Thanks

[@thediplomasta5891]

No, it does something. But I think it is all inside the brain box. Not sure how, exactly. Yamaha really wants you to buy that factory service manual, don't they? 🤨

[@TheAshlynn05]

@@thediplomasta5891 I've found that the wire comes from the icm area so when the key is energized; the needle inside the choke circuit, starts to move. So it only supplies power when the key is on.

[@Crackernecker]

Great video! I have a 1999 90hp 2 stroke yamaha tlrx that has me perplexed. It keeps blowing out the prime start diaphragm at high rpms. I've checked the wax plug pin. Checks ok. Ever see such a thing? Great channel!

[@DangarMarine]

I haven't seen that before. Are compression gasses escaping form somewhere?

[@Crackernecker]

Are you suggesting possible Reed valve failure? I thought maybe the reeds in the prime start itself could be too tightly seated. I did bend them just a smidge so they didn't press so hard against the plate. I have already replaced the diaphragm again (3rd 1 in a week) . Went out for a short run after install and all seems well. I'm really confused as to what's going on. Any thoughts would be greatly appreciated.

[@jessicabanker5555]

mine is the same as in the video the elect primer system but the oil tank has been took off I have to mix fuel and oil in the gas tank

[@beerturbogarage]

Hi Mate, how close is the yamie prime start to the merc cold start? i actually have the same 90hp 2 stroke your mates has (the one you allways says its too/a bit noisy for audio)........i tried my first cold start today and it took forever, should have read the manual, dident even realise you had to push key in to "choke"

[@DangarMarine]

The Merc system is different, and in some ways I like it more as you have manual control over it. Even once the motor is started if begins to sound like it is going to stall you can just push the key in again to give it an extra hit of fuel. The key just activates a solenoid that allows more fuel directly in, this system is heat controlled and there is nothing you can do to affect it.

[@shayhall9109]

Great tutorial , I have one question I replaced the gaskets and diaphragm on my yamaha 50 TLR. But I am experiencing fuel leaking when the motor is trimmed up from bottom of the enricher. Any ideas what could cause this ? Thanks and keep the videos coming.

[@DangarMarine]

If all the gaskets and seals are good, it could be a crack in the housing. It could also be that it is running from somewhere else and looking like coming from there because that is where it drips.

[@shayhall9109]

@@DangarMarine you are spot on , it was running from the second carb and dripping from the corner of the enricher. Thanks for replying and keep the videos coming.👍

[@thediplomasta5891]

What kind of hose clamps are on the short little hose that feeds the middle carb? Zip tie won't seal it. Has to be the spring clamp or a snap clamp, like OMC uses on their VRO pump hoses.

[@anthonymiller3256]

So from my understanding, the plunger is always "retracted" and the enrichment process automatically happens with every cold start? Once voltage has been applied (or engine running for several minutes) the plunger extends and the system leans out. There is no need to push in on the key like my old Johnson with the solenoid that directly inject fuel while pushing in? I have a 2001 75hp Merc ELPT 4 stroke. While starting, the engine stops cranking when I push in on the key, then resumes cranking when I stop pushing in on the key. If the system automatically "enrichens" then why even has a "push to choke" ignition switch?

[@sergebertetdarkside]

Hi, when do the choke plunger go back in it's original position after testing it goes out from the coil? When is the pluger activated when starting he motor? It depends on the temperatures, it is automatic? I have a F50AET Yam outboard hard to start when cold. Maybe you already said that in the video but since I'm french I do not understand everything, sorry. Very good video, go ahead.

[@DangarMarine]

When you start the boat electricity flows through the plunger and starts to heat up a wax plug. This is what pushes the needle out. Once you turn the motor off it starts to cool and will slowly retract.

[@sergebertetdarkside]

Many thanks for your quick answer.I'll try to check that.

[@zx001961]

I have a problem with the Yamaha 115 can't find any help you can run it like 28 mph all day long but if you open it up and start trimming it out in a second or two it will go to missing and have to shut it down for a second restart it and it runs long as you don't go over 28 mph but if you open it on up it does the same thing there has been few times when I first put it in the water I can open it up and run it wide open for a little while and it starts doing that

[@barrynoel6908]

What if you turn it to emergency bypass and the motor dies?

[@jeffmckenzie9997]

Love the videos, very informative. I find I now need a prime starter for my 03 yamaha 50hp, can you reccomend any recyclers down south as I am having no success finding one in NthQld. Cheers

[@DangarMarine]

Hi Jeff. There are two main ones in Sydney, Sea Sea Marine and Arizona. Both are worth a try.

[@jeffmckenzie9997]

Tks

[@SY-Selene]

Hmm, after watching this video, I think the prime start on my engine is working fine. It starts good, but after a few minutes of running the idle rpm starts to drop slowly up to a point were the engine dies, when I put a gear in. This really sucks, because I start the engine, fidle with the ropes and when everything is ready to go in reverse: "Click - reverse in" -> engine off -> boat is adrift. :) However, according to your explainations, the carp should have 2 seperate idle rmp systems. ... Need to read the service manual about that. PS: I fidled with so many outboards already, but never came across such a cold start system. My engine is a 4 stroke 9.9HP from 1995

[@rodashford1151]

hi dangar what would be the likely cause of a 3cyl 40 hp yamaha 2 stroke stalling whenever you try to come back to an idle?

[@DangarMarine]

It could be that the idle jets are blocked in the carburettors or that the idle speed or mixture is set too low.

[@justynnharcourt8825]

Hey Stu I'm out on Bar Point and having a few issues after converting a CV75 to a 90AETO. I've bypassed the oil injection-dont really know if thats good or not. Also having issues with cold start. About to do all the tests but before I start I want to confirm that the blue lead runs to the old choke switch on the ignition ie pressing the key in or does it run elsewhere? Not sure what the lighting coil is exactly..

[@justynnharcourt8825]

I've just been doing a little more googling and I've answered my own question on the blue lead. No its doesn't go to the old choke switch. However I'm still not sure where it goes..

[@DangarMarine]

Hey Justynn, I would have thought it was related to some sort of choke/prime start if it is blue. Lighter blue is also used for the trim tilt, maybe that is it?

[@thediplomasta5891]

It goes onto one of the green leads from the rectifier. Yamaha wire colors, still don't make any sense to me.

[@MvB8587]

Hi yet another great vid... Any chance you can let me know where I can buy a new prime start therml valve Yamaha au have no stock. And can't seem to find any available.... Or what to do if can't get them...

[@DangarMarine]

You might need to try an outboard wreckers.

[@MvB8587]

Tryed to but as yet no luck.

[@MrMatthewkirby]

Hi Stu, great video, I have a 60hp Yamaha with this prime start. I have ultrasonically cleaned the carbs meticulously with airline and carb cleaner. Replaced the prime gaskets and diaphragm. Checked the pistol moves and there is 12v when running. Still a bugger to start, but squirt some easy start and it's away! Also turn the red enrichment to emergency and it starts. Crankcase suction pipe is fine and motor seems to run well in a tank. It's a new to me and I have never taken it out but runs well and sounds nice. Any ideas??? Thanks Matthew

[@DangarMarine]

Hmm, it does sound like a problem with the prime start, but that's odd given the needle is moving. Obviously fuel is getting through the unit as the emergency mode helps. Could be a blockage in the passage that the fuel takes through the needle mechanism.

[@MrMatthewkirby]

Thanks Stuart, I’ll take it apart again!

[@MrMatthewkirby]

Had another look at this and the problem is the plunger doesn’t go back far enough when it’s cooled down. Tested by sucking/blowing on the pipe that powers the pump on the prime start from the middle inlet. Moving the red lever to emergency lots of fuel pumped through the pipe to the top inlet. Push the plunger in and it stops. Just got to pay £150 for a new one

[@andrebroussard2896]

Stuart, I have a 1997 Yamaha 40 2 stroke that surges when at high RPM, 4,500. It drops about 200 RPM momentarily then picks back up. I’ve cleaned the carbs, filter, replaced the fuel pump but the issue persists. Any ideas?

[@DangarMarine]

Could be vacuum leak, head gasket or ignition weirdness.

[@calumaitchison]

Does this system make the outboard run rough after a full speed blast when backing the throttles back down? Mine runs rough from idle up-to 2500rpm then it's smooth

[@DangarMarine]

It can do if it is not fully extending making it run rich, but would probably not be worse after a full throttle run. Could be heat / cooling system related.

[@kiwi-kt2bo]

i liked this video purely for the panning duck shot.

[@tomislavpelin7904]

Hi, Stuart. Do You have eperience and consequences of ruptured membrane on this fuel enrichement system? I've recently bought used 600hrs Yam 90 2 stroke, and it seems that fuel economy is really bad. 40 l/hr or 1.45 l per nm and more (16 ft bowrider). Spark plugs are pretty black and full of carbon ( rich mixture). Had to clean it twice during the ride. Master fuel pump seems ok.

[@DangarMarine]

I'd definitely be looking into the enrichment system. I'm trying to remember how this interacted with the fuel pump, but if the needle is stuck withdrawn it will be running very rich the whole time and causing all the symptoms you have described.

[@krzykamienski]

Check one of the starter-jet wire cable under the rubber cover. I have been swimming for over a year and spark plug was black ...

[@visual74]

Hello Stu. First post here. I have two questions for my Yamaha 2 stroke 90tlra. Is the prime starter necessary for the engine to start or can it start without it even when the engine is cold? Also my RPM does not go past 2000 after about 10 minutes of riding. I'm thinking it is in safe mode but I do not hear any beeps telling me why it's stalling. When I checked the gauges, the wires have been cut off. It must be the oil sensor or the temperature sensor that isn't connected. How do i go about connecting the sensor wires again so I can hear beeps when there is a problem? I have been trying to find a solution to the low RPM and this is what I have concluded. I am totally new to boating and learning the hard way from day one. Wish I can just get this engine running already. BTW, thank you so much for all that you do.

[@DangarMarine]

No, the prime starter isn't necessary. Many engines will start in warmer weather without it. The alarm for the limp mode is normally in the forward controls I think. You might need a tech to connect the outboard to their diagnostic computer to find out what codes it is throwing.

[@krisjoha10]

awesome :) could u do a video about adjusting carberouter(?) and hooking up the rpm meter? sorry for bad english :P

[@keimolantio]

This is a good idea! And with vacuum meter

[@DangarMarine]

Yes, I really must do a good carburettor tuning video soon. Stay tuned!

[@krisjoha10]

awesome! :D

[@filippocunsolo6764]

My Yamaha Zuma will not start up. I need help. Can you help me

[@marcoaurelio9879]

Good morning, I have a 1996 Yamaha 60hp three cylinder 1996 engine. How do I adjust the air bolt on the carburetor in the carburetor of this engine?

[@DangarMarine]

This video goes through doing that. kzbin.info/www/bejne/mKSrdICAo7eMb6M On two strokes you don't do the vacuum gauge part though.