F20 startup issue +video

[merc200dalarna]

Needle seats are not supposed to move..at all.

Oh I know, but my guess is that the rubber expanding and contracting allowed it to do so. Ever so slightly each time. Either that or the japanese engineer had a very bad monday back in 2013 when assembling it.

[merc200dalarna]

It's only about 10 or 11pm at night in Sweden. How about a moonlight cruise to test it?

But it's on the trailer in my backyard, doubt my neighbours would like me to run the motor now. Most likely I have it run tomorrow, but we have so little daylight now, it sets at 4:15pm allready. it's 11:18pm as I write this.

[panasonic]

But no, the seam is not paralell to the carb housing. It is now lower in the end opposite of pivot/needle. I measured it, struck it with a hex-nut on top, then measured again and it had seated down 1 mm (of the 2mm, so half) and I didn't dare to strike it again. My guess is that it moves from temperature, I use the motor even now when we have below freezing. The o-ring allows for the travel when freezing and warming (Only my guess.)

Needle seats are not supposed to move..at all.

[merc200dalarna]

I'm thinking Moto X previous owner dinked with it. You know how them Moto X guys are.

Quite possible, since had 2 cars and one snowmobile for sale at the same time he sold me the outboard. He seemed like the type that tinkers with everything motorized. I'm sure you know the type, those who never seem to be able to wash the oil of their fingers no matter how they try their fingers are always sooty and greasy ; )

[panasonic]

Hell, I took a gamble and pushed the seat in about 1 mm. The pivot pin and the screw are flush now, the screw is tightened. (unfortunately the float isn't according to spec, but I will have to go with it and hope it works)

As long as the float is "close" to being Parallel to the surface where the carb bowl mates it will be fine. Don't get caught up to much with the measurement in the Service manual.

Like Scott said they usually are pushed in until they bottom out in the bore.

Now will it stay put...that would be my concern.

I bet it will run just fine now.

I am sure you will let us know...go catch some fish!!

[merc200dalarna]

Technically, you SHOULD NOT have been able to push the seat in further..

That seat SHOULD bottom out in the carb housing... Is it fitting snug in the body??

Is the float (seam) NOW about parallel with the carb body?? (as if you adjusted with the mounting screw like before)

How it moved is beyond me...

*If Yamaha wanted/allowed any adjustment, it would have been engineered into the FLOAT itself (usually a metal tab)...

But no, the seam is not paralell to the carb housing. It is now lower in the end opposite of pivot/needle. I measured it, struck it with a hex-nut on top, then measured again and it had seated down 1 mm (of the 2mm, so half) and I didn't dare to strike it again. My guess is that it moves from temperature, I use the motor even now when we have below freezing. The o-ring allows for the travel when freezing and warming (Only my guess.)

[pstephens46]

I'm thinking Moto X previous owner dinked with it. You know how them Moto X guys are.

[TownsendsFJR1300]

Those silicone "rubber" parts seem to be indestructible. Unless you torch them.

He's got a rubber tipped (or similar) needle so the seat is very likely brass.

Why it moved (if in-deed it did) is the $100 question...

[pstephens46]

Those silicone "rubber" parts seem to be indestructible. Unless you torch them.

[99yam40]

could the chemical carb cleaner have attacked the o ring on the seat?( if it has one)

hard to tell when the parts break down does not even show the seat

[pstephens46]

It's only about 10 or 11pm at night in Sweden. How about a moonlight cruise to test it?

[TownsendsFJR1300]

Technically, you SHOULD NOT have been able to push the seat in further..

That seat SHOULD bottom out in the carb housing... Is it fitting snug in the body??

Is the float (seam) NOW about parallel with the carb body?? (as if you adjusted with the mounting screw like before)

How it moved is beyond me...

*If Yamaha wanted/allowed any adjustment, it would have been engineered into the FLOAT itself (usually a metal tab)...

[merc200dalarna]

Hell, I took a gamble and pushed the seat in about 1 mm. The pivot pin and the screw are flush now, the screw is tightened. (unfortunately the float isn't according to spec, but I will have to go with it and hope it works)

[merc200dalarna]

OK there is one of two things going here:

1 The needle is to long..but it is the one that came with the engine. But that does not mean it is the correct one (somebody may have put the wrong one in there) The only way to know for sure is get a new one and compare...simple as that.

2 The needle seat has moved. There are a couple of different brass needle seats on the go. There is the press in type, with or without an O-ring on them. And the screw in type which usually have a hex head or a screwdriver slot for installing or removing them (but not always)

Seeing that the parts break down doesn't show the seat as a replaceable part... I would say yours is a press in type. it is not meant to be removed after installation.


First try to contact the person who sold it to you and see if he fooled with the carb.(changed any parts)

If it was my carb (do at your own peril) I would first try to turn it with a pair of pliers.

If it does not turn, I would get a socket that is approx the same diameter as the seat, support the carb solidly and gently tap on the seat and see if it moves...measure with your calipers to see any difference. All the carbs I have seen with pressed in seats are just pushed in until they bottom out in the bore.

Note: seats in pics are not from your carb

Good Luck

Nice pictures, so basicly, the seat can move on the o-ring, I mean the o-ring is soft and pliable.... If I only knew that the seat should bottom out? Can I be sure it should? Because if it bottoms out at the right height, I would dare to push it in??? EDIT# I still believe there is an o-ring on my seat too, because I can see a small gap around the edges.

[merc200dalarna]

This is crazy. Can you put a flat piece of metal over it and press down a tad harder? Where is the Moto X previous owner? Could you ask if he ever touched that carb? Are those seats generally just pressed it? Any sealant?

I don't have any phone number for the previous owner, lol, we made the deal at a local gasstation. (haha, I had the motor checked by yamaha sweden for insurance issues and what not, it was bought by that dude.) I checked a video by "eric edic" on youtube disasembling a yamaha carb, I can almost see that my seat has moved out compared to the video. But I still want a measurement before I press down harder. I could use a vice or similar, but i don't want it out of spec the other way instead.