# 2006 Yamaha 25hp 2stroke - air mix/pilot screw



## yobata

I cleaned the carbs on the motor today. I noticed a pilot adjusting screw on the top carb, but not on the bottom one. Anyone know of where I can find a diagram to make sure the bottom carbs isn't supposed to have one too? Maybe the previous owner broke it off when cleaning carbs...


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## RunningOnEmpty

yobata said:


> I cleaned the carbs on the motor today. I noticed a pilot adjusting screw on the top carb, but not on the bottom one. Anyone know of where I can find a diagram to make sure the bottom carbs isn't supposed to have one too? Maybe the previous owner broke it off when cleaning carbs...


Part # 26 http://www.boats.net/parts/search/Yamaha/Outboard/2006 and Later/50TLR/CARBURETOR/parts.html


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## yobata

RunningOnEmpty said:


> Part # 26 http://www.boats.net/parts/search/Yamaha/Outboard/2006 and Later/50TLR/CARBURETOR/parts.html


I think this may be for the 50hp motor - the screw on the 25hp goes in at a diagonal angle (at least the one I can see on the top carb)

Here is the only diagram that I have been able to find, but it doesn't tell me (or at least I am not reading it clearly) of *whether or not BOTH carbs have this screw and spring, and if so, are they the same part number*: http://www.boats.net/parts/search/Yamaha/Outboard/2006 and Later/25ESH/CARBURETOR/parts.html
http://www.boats.net/parts/search/Yamaha/Outboard/2006 and Later/25ESH/CARBURETOR/parts.html
thanks for any help you guys can provide!

Also, if the bottom screw is broken off, how would I even begin to try to remove it? It is brass I believe, maybe I can cut a straight slit into the top of it and use a small screwdriver???


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## RunningOnEmpty

yobata said:


> I think this may be for the 50hp motor - the screw on the 25hp goes in at a diagonal angle (at least the one I can see on the top carb)
> 
> Here is the only diagram that I have been able to find, but it doesn't tell me (or at least I am not reading it clearly) of *whether or not BOTH carbs have this screw and spring, and if so, are they the same part number*: http://www.boats.net/parts/search/Yamaha/Outboard/2006 and Later/25ESH/CARBURETOR/parts.html
> thanks for any help you guys can provide!
> 
> Also, if the bottom screw is broken off, how would I even begin to try to remove it? It is brass I believe, maybe I can cut a straight slit into the top of it and use a small screwdriver???


I'm sorry LOL. I don't why I gave you the 50hp info? The newer Yamaha 2 strokes came with a plastic cap that covered the adjustment screws. It was a EPA thing to keep people from running richer than the factory spec. I would slot the screw for removal if possible. If it's too deep you might be able to use a small left handed drill bit to get a bite on it? I can almost guarantee the older air screw that has the slotted head will work in your 06 carbs http://www.boats.net/parts/detail/yamaha/Y-6L2-14323-00-00.html


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## yobata

RunningOnEmpty said:


> I'm sorry LOL. I don't why I gave you the 50hp info? The newer Yamaha 2 strokes came with a plastic cap that covered the adjustment screws. It was a EPA thing to keep people from running richer than the factory spec. I would slot the screw for removal if possible. If it's too deep you might be able to use a small left handed drill bit to get a bite on it? I can almost guarantee the older air screw that has the slotted head will work in your 06 carbs http://www.boats.net/parts/detail/yamaha/Y-6L2-14323-00-00.html


This is what the one on the top carb looks like:










http://www.boats.net/parts/detail/yamaha/Y-6L2-14323-11-00.html

You can see the suspected breaking point that is just above the threads, it's like they made them to break

Do you think I should use the one you suggested or this one? It doesn't have any limiting cap that I can see, it's just a thumb adjustable screw as opposed to the slotted flathead adjustable one...


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## RunningOnEmpty

I just did some reading and others have swapped the problematic EPA screws for the older style screws. You probably need a spring as well http://www.boats.net/parts/detail/yamaha/Y-646-14212-01-00.html


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## yobata

RunningOnEmpty said:


> I just did some reading and others have swapped the problematic EPA screws for the older style screws. You probably need a spring as well http://www.boats.net/parts/detail/yamaha/Y-646-14212-01-00.html


Thanks!!! I will try it out and report results


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## RunningOnEmpty

I ran those carbs on a modified yamaha 30hp 3 cylinder. I also found that the tohatsu 40hp uses them as well.


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## No Bait / Lures Only

My 2006 25 Yamaha 2 cylinder 2 stroke low speed screw on the bottom carburetor vibrated out and was acting crazy. Viewed the missing screw and brought it to mechanic, he replaced both screws with the older style screwdriver slotted low speed screws. Motor is like new again.


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## yobata

I ended up replacing with the older style screws as well. I was a bit nervous when I received the parts from my local supplier - the replacement slotted screws have a longer point section than the older thumb screws,



















but in the end it did not matter. The motor runs and idles SO much better now. Once warmed up I can actually idle at its lowest setting without stalling out.


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## RunningOnEmpty

I was wondering how it worked out for you. I'm glad I didn't give you bad advise lol


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## yobata

RunningOnEmpty said:


> I was wondering how it worked out for you. I'm glad I didn't give you bad advise lol


Thank you for the help! I also just set the new screws out 2 turns. The sticker under the cowl says 2 +or-3/4. I can play with it a little but want to run it a bit longer to see if needs adjusting... Sometimes I fiddle too much with stuff


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## RunningOnEmpty

yobata said:


> Thank you for the help! I also just set the new screws out 2 turns. The sticker under the cowl says 2 +or-3/4. I can play with it a little but want to run it a bit longer to see if needs adjusting... Sometimes I fiddle too much with stuff


When it gets cold your motor will need more fuel and by backing the screws out a tad will allow for easier cold starts and a improved throttle response. Nothing wrong with fiddling and learning about your motor. It may get you back to the ramp some day. I know I have used my _Macgyver skills many times out on the waters. I have some crazy stories! _


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## Salt of the Water

Bump on an old thread.

I'm about to do a carb job on a new to me 25hp 05 2 cyl 2 stroke, because it isn't idling right. Motor will idle (rough but doesn't die) at full choke, when I push the choke in motor revs higher for a few seconds and then dies. Should I go ahead and buy the old style screws to swap them out while I have the carbs out? 

Also, the previous owner left the top two screws holding the plastic intake cover off. Only the bottom two are holding the intake cover on. Should I be concerned about anything other than buttoning it back up? Not sure if the intake breathing too much may have caused other issues...


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## No Bait / Lures Only

RunningOnEmpty said:


> I just did some reading and others have swapped the problematic EPA screws for the older style screws. You probably need a spring as well http://www.boats.net/parts/detail/yamaha/Y-646-14212-01-00.html


Same issue with my 2006 25 2 cylinder 2 stroke, old style screws will work.


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## yobata

Salt of the Water said:


> Bump on an old thread.
> 
> I'm about to do a carb job on a new to me 25hp 05 2 cyl 2 stroke, because it isn't idling right. Motor will idle (rough but doesn't die) at full choke, when I push the choke in motor revs higher for a few seconds and then dies. Should I go ahead and buy the old style screws to swap them out while I have the carbs out?
> 
> Also, the previous owner left the top two screws holding the plastic intake cover off. Only the bottom two are holding the intake cover on. Should I be concerned about anything other than buttoning it back up? Not sure if the intake breathing too much may have caused other issues...


Hey just to report back, I swapped for the older style screws and it works great! And less chance of it breaking! The part number is: 
*6L2-14323-00-00*

I would also just order the extra screws for the intake cover. They're cheap enough...


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## Dadvocate

Thanks Yobata for posting this. Replaced mine 2 weeks ago on 2006 25ESH with above part #. Cleaned carbs, idles better and another MPH faster


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## Salt of the Water

Ordered old style screws. Will install when I do the carb job.


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## RunningOnEmpty

Salt of the Water said:


> Ordered old style screws. Will install when I do the carb job.


I like the older style more.


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## State fish rob

yobata said:


> I think this may be for the 50hp motor - the screw on the 25hp goes in at a diagonal angle (at least the one I can see on the top carb)
> 
> Here is the only diagram that I have been able to find, but it doesn't tell me (or at least I am not reading it clearly) of *whether or not BOTH carbs have this screw and spring, and if so, are they the same part number*: http://www.boats.net/parts/search/Yamaha/Outboard/2006 and Later/25ESH/CARBURETOR/parts.html
> thanks for any help you guys can provide!
> 
> Also, if the bottom screw is broken off, how would I even begin to try to remove it? It is brass I believe, maybe I can cut a straight slit into the top of it and use a small screwdriver???


They make some really good screw exractors these day ,take care drilling out brass. Grabs alots ,being soft. A drop kerosene will help


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## Salt of the Water

Suck it new style epa screws and whoever left the snapped off screws inside this carb. If anyone runs across this thread trying to get idle screws with broken heads out of a Yamaha carb, here's how I did mine. 


Use an automatic center punch to make an indent in the center of the screw. 
Drill out a tiny bit of the screw. 
Tap in a tiny flathead like you use for eyeglasses (you can get a better bite if you drill out some of the screw so it can deform around your screwdriver) 
Back out the screw 1/2 turn until the screwdriver slips 
Cuss some and drink a beer (to improve morale) 
Repeat steps 3-5 until old screw is removed or you can't see straight. You may need to sleep it off if step 5 is winning the race against step 3 and 4.
Hurl the old screw across the garage in triumph 
Admire the solidity of the new (old style) screw you're installing and the rugged simplicity of the way things used to be before silly engineers tried to design around bureaucracy run rampant.






  








Broken idle air screw




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Salt of the Water


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Jan 20, 2019












  








Broken screw




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Salt of the Water


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Jan 20, 2019












  








New (old style) idle screws




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Salt of the Water


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Jan 20, 2019












  








Much better




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Salt of the Water


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Jan 20, 2019


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## yobata

@Salt of the Water 

Haha great post! Hopefully you have the springs too so the vibrations of the motor running don't back the screws out?


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## noeettica

Any of you guys have a shop manual I could pay for some pages ?

I got NO SPARK !!!


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## Guest

Get me the year, I’ll send ya the specs!


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## Salt of the Water

yobata said:


> @Salt of the Water
> 
> Haha great post! Hopefully you have the springs too so the vibrations of the motor running don't back the screws out?


Yeah once I realized the old screws were snapped off and the springs were gone I got them on order.

Ran it some anyway this weekend to see if the carb rebuild fixed idle issues. Ran better than before (could get it off choke now) but still couldn't back of the throttle to lowest idle without it dying.

Choke = improved fuel suction. Therefore dying when removing choke = it's not pulling fuel correctly. Where's the idle jet... Under the black rubber cap I didn't remove.. Carb back off, idle jets out, here's the result.





  








MVIMG_20190121_183504




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Salt of the Water


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Jan 22, 2019








Most of it was from the jet in the bottom carb. Yep, that much grit will make it idle like $hi!. I'll crank it up tomorrow. Hopefully I've got it sorted now.


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