# 1999 Yamaha 6 hp 2 stroke question



## MissionSix (Feb 25, 2018)

does anyone have a good manual or video showing the carburetor? Just bought motor and I am VERY new to outboards. Definitely am mechanically inclined but just want to protect my investment and get as much info as possible. Needing to take off, clean, and out back on my carb.


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## NativeBone (Aug 16, 2017)

Check out boats.net

They have diagrams breaking down the carb.


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## MissionSix (Feb 25, 2018)

NativeBone said:


> Check out boats.net
> 
> They have diagrams breaking down the carb.


Thank you sir


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## yobata (Jul 14, 2015)

YouTube is your friend. The 9.9 is not much different than a 6hp


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## MissionSix (Feb 25, 2018)

yobata said:


> YouTube is your friend. The 9.9 is not much different than a 6hp


That’s kinda what I figured. Heading home from work now to attempt getting it cleaned up. The only other thing I can think of if this ends up not being it is exhaust ports being plugged.


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## NativeBone (Aug 16, 2017)

MissionSix said:


> Thank you sir


 no problem!


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## Guest (May 7, 2018)

Careful with the idle air screw, some of the yami’s have a deep taper in the shaft and can break. Also, the orifices in that carb are probably very small so just be thorough with your cleaning and should be fine. I doubt exhaust is plugged unlees there a big paper wasp nest up in there somewhere.


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## yobata (Jul 14, 2015)

@Boatbrains I had to replace my idle air screws because one of the "heads" above that deep taper broke off (prior to my acquisition of the motor). That style is often called the EPA style lol I replaced both carbs (2 on my 25hp) with the style that has the flat head to fit a screwdriver and no taper...


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## MissionSix (Feb 25, 2018)

I’m not thinking it’s the exhaust honestly. I’m leaning more towards plugged up jets. I completely changed out the gas again to ensure it’s got good gas. Also my plugs are fouling still. I think they were so bad off they are pretty much shot and not burning good. Got new plugs. Ordered a rebuild kit as well. Going to soak jets and all today again just to be sure. Hope it works good cuz I’m making a trip in it tomorrow.


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## NativeBone (Aug 16, 2017)

If you can get your hands on a welder tip cleaning rods, that works the best. Comes with different sizes. Like 5 bucks from harbour fright


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## NativeBone (Aug 16, 2017)




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## MissionSix (Feb 25, 2018)

That’s exactly what I was thinking actually. I have a hardware store by my house that has them. About to go grab one now.


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## MissionSix (Feb 25, 2018)

Now, the next problem. the oil seal on my propeller seems to be busted after hitting a log today. Why me!!???!!


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## MissionSix (Feb 25, 2018)

Ok now seriously. What the hell is going on with my motor. Everything is right. Plugs. Mixture, everything else. But when I’m hear while the tank is plugged up, it only goes a little more than idle rpm. When I disconnect the fuel line, it gradually picks up then goes wide open.


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## Guest (May 7, 2018)

Did you clean the carb yet?


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## Guest (May 7, 2018)

The condition you just described sounds like it’s flooding, then when you disconnect fuel line it leans up a little, then when starts to run dry it leans out and takes off. Check needle and seat, also check float height


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## NativeBone (Aug 16, 2017)

Boatbrains is on it. The float could be sticking.........


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## MissionSix (Feb 25, 2018)

Float moves flawlessly. I’m literally at my wits end! About to...gulp...take it to a shop.


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## Guest (May 7, 2018)

Pull the fuel pump and break down, could have a torn diaphram allowing fuel directly into crackcase causing similar flooding condition. Symptoms would do the same when disconnecting fuel line


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## MissionSix (Feb 25, 2018)

Ok cool. Next task. Thanks!!!


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## MissionSix (Feb 25, 2018)

Nope. Diaphragm is in tact.


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## Guest (May 7, 2018)

Both? There is a plastic and a rubber one.


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## MissionSix (Feb 25, 2018)

2 rubber diaphragms. Both are in tact.


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## Guest (May 7, 2018)

Make sure number 8 is in place.


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## MissionSix (Feb 25, 2018)

Yeah I don’t have that.


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## MissionSix (Feb 25, 2018)

Although the jet looks like it is 2 pieces.


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## Guest (May 7, 2018)

That’s the problem then, providing this is your carb. Just a quik boats.net search of 99 yami 6hp for the diagram so I could help more so double check the diagram. That plug has to be in the carb though.


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## Guest (May 7, 2018)

It’s just a small flanged black rubber plug that fits in the hole covering the idle oriface.


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## Guest (May 7, 2018)

They tend to hit the floor sometimes if you don’t know they’re in there.


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## MissionSix (Feb 25, 2018)

Ugh. Dude I seriously hope it’s that simple. Plus I’ve spent WAY too much money already!!!


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## No Bait / Lures Only (Apr 10, 2011)

yobata said:


> @Boatbrains I had to replace my idle air screws because one of the "heads" above that deep taper broke off (prior to my acquisition of the motor). That style is often called the EPA style lol I replaced both carbs (2 on my 25hp) with the style that has the flat head to fit a screwdriver and no taper...


My 25 Yamaha had the same issue as well, replaced screws. In addition the fuel filter o ring was bad and that drove me wild trying to find the air leak, that's like a $ .50 cent fix...


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## yobata (Jul 14, 2015)

MissionSix said:


> Ok now seriously. What the hell is going on with my motor. Everything is right. Plugs. Mixture, everything else. But when I’m hear while the tank is plugged up, it only goes a little more than idle rpm. When I disconnect the fuel line, it gradually picks up then goes wide open.


I'm bringing this up as just another thing to check, it's a simple check: the new plastic fuel tanks have a weird new EPA cap on them. I recently bought a new one and while under power my motor started really bogging down. I turned around and went back to the ramp. When I got home I realized that the new cap has a vent that you can unscrew manually, his realization came when I saw the new plastic fuel tank had collapsed in itself. With the vent closed, the fuel pump was sucking gas, but was struggling without the tank being able to pull in new air...


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## Guest (May 8, 2018)

EPA outboard=expect problems annually!


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## MissionSix (Feb 25, 2018)

I have an external gas tank. It has a little weep hole it appears. Is that little rubber piece ported?


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## Guest (May 8, 2018)

The rubber plug in carb is not ported, it is a plug. Gas tank, not sure.


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## MissionSix (Feb 25, 2018)

So I should be able to just plug that jet from the top and be ok? I did however order a carb rebuild kit though. I was just asking in case


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## Guest (May 9, 2018)

Don’t plug the jet. That’s the low speed jet. There is a hole that connects the high speed and low speed passages. Without that little rubber plug though too much fuel gets pulled through the low speed side. If you can find something that fits without blocking the passage between high speed/ low speed passages then you might be able to test, but if you ordered parts then I’d just wait til’ they cone in and fix it right.


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## MissionSix (Feb 25, 2018)

I am definitely going to wait. This motor has made me miss out on an epic trip today out of Buras! However next week it’s on!!


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## MissionSix (Feb 25, 2018)

Update on carburetor. Ordered a kit through Wholesale Marine. Huge mistake. Opened the repair kit and immediately realized it wasn’t even close. So this weekends short trip is out. Ordered a new one from iboat.com and I feel confident I have the right kit.


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## Guest (May 11, 2018)

If you have a dealer or outboard repair place near by, I’m willing to bet there is a tech with one of those plugs in their tool box for just such an occasion.


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## MissionSix (Feb 25, 2018)

Boatbrains said:


> If you have a dealer or outboard repair place near by, I’m willing to bet there is a tech with one of those plugs in their tool box for just such an occasion.


Dude I hope so. Lol. I’m going to go check tomorrow now that you say that.


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## MissionSix (Feb 25, 2018)

I have to say, so far having a motor, has been nothing but a headache and problem for me. Going from a kayak to a Gheenoe was exciting and looking forward being able to take my youngest son and wife out. It has literally been nothing but headaches since getting a motor.


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## yobata (Jul 14, 2015)

MissionSix said:


> I have to say, so far having a motor, has been nothing but a headache and problem for me. Going from a kayak to a Gheenoe was exciting and looking forward being able to take my youngest son and wife out. It has literally been nothing but headaches since getting a motor.


It's not always like that. In 2016 I bought a 10 yr old motor - a 2006 2 stroke 25hp Yamaha for $1300. It has been awesome and easy to work on if the carbs need cleaning, water impeller need changing, etc. It just depends on who was taking care of the motor before you...


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## MissionSix (Feb 25, 2018)

yobata said:


> It's not always like that. In 2016 I bought a 10 yr old motor - a 2006 2 stroke 25hp Yamaha for $1300. It has been awesome and easy to work on if the carbs need cleaning, water impeller need changing, etc. It just depends on who was taking care of the motor before you...


I do think that I have a great motor and will have one for a long time. Just frustrated is all.


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## MissionSix (Feb 25, 2018)

Boatbrains said:


> Both? There is a plastic and a rubber one.


Well sir, you were dead on about literally everything! The shop by my house had the plastic/rubber piece to go on top of my idle jet. Put it in and it ran like a dream! Thank you again 4 all your help!


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## Guest (May 16, 2018)

Awesome, glad you gott’er goin!


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