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.

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.

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

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

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

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.

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

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.

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

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!

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!

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

Hello from Greece,nice job!

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

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.

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

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

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!

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

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

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

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.

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.

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.

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.

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.

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

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

Very good channel for outboard lovers.

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

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!

Thank you sir for the information I needed to diagnose.

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

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

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

Love your videos! Extremely informative. Keep them coming.

Outstanding explanation. I became your newest subscriber! Thank!

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.

love your work friend, thx for sharing your knowledge

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

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

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.

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!

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

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?

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.

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.

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

I have a 93 Yamaha 70. I cleaned all three carbs but didn’t mess with the prime start system. It won’t start without some carb spray. Once it starts it idles fair and will restart instantly if warm. Today it would loose prime after about 5 minutes of idling. The bulb pump will not get real hard so now I’m thinking it’s the fuel pump.

Do you have a measurement of the valve height at room temperature before heating?

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

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

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

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

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

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!

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

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

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!

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

love the duck transition 1:45

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?

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

Would it be a good idea to premix feul just a bit. Maybe 60:1. As well as using oil injection. I was told from one mechanic that he never seen one fail. I just bought a 2004 40. Engine has just come from mechanic. It cranks more cold starting than I would like. Compression I thought was way low. But he said those particular engines don't have high Compression. 105, 95 and 105. Is Compression. Engine runs really good. Just don't cold start very easily.

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.

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

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

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?

On the prime start solinoid...I get no power or signal when cranking.... 2017 20 hp yamaha: how and where does this solinoid get its 12v power? Update: the prime start solinoid has no resistance using ohm meter test - tests like dead shorted - tried changing range on ohm meter... I put 12v power to solinoid leads...normally you would see tiny spark...nothing.... However, the solinoid plunger extended with 12v power hooked up after 3 minutes ... I cleaned carb well, tested fuel prime start solinoid What I don't know is where the power comes from to excite this solinoid... is it during engine running or ignition turned on... Any feedback from anyone is will be appreciated

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

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.

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

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.

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

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.

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?

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

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

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

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 .

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

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.

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?

YAMAHA 2 stroke the best !!!

i liked this video purely for the panning duck shot.

I just got a 1995 Yamah P50TLRT with prime start. I took the prime start plunger motor off and the plunger is gone. Does that cause it to run rich all the time... or does it cause it to run lean at start up? Motor starts just fine, but plugs are fouled and it will not rev well.

Thanks for the video! I'm having trouble with the same exact system you was working on. Motor will idle long as I rotate the switch to "emergency and on". Once I leave it on the "on" position it'll slowly die. Any ideas?

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"

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?

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

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?

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

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.

Cheers mate!

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

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?

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

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.

you should run a small marine machenic course :) your students will become a proper professional machenics in 6 months :) way better than those mobile machenics lol love your videos Mate , havnt seen a person putting these types of videos and getting nearly no thumbs down ... Amazing job . i would bring my outboard to you for service if you were in perth :) have a good one :)

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