Mystery Carbs

[DEEBS11]

Dynojet instructions:

https://www.dynojet.com/installguide/4101

[autotech44]

I've read the instructions and I'm gonna stay with the dynojet kit for two reasons. One is way more expensive buying all the OEM stuff, and two wondering what affect drilling out the slide lift hole will have if I go back. I didn't see the main jet you used? Something on the site is messed up and you get misc links when using the number sign.

[DEEBS11]

I use 130s at sea level.

[autotech44]

I use 130s at sea level.

Ok. Then that should eliminate the risk of the stage 3 main being too rich. Cool.

[DEEBS11]

It looks like you have a good start. Obviously there are other components of the bike to consider as well.

[autotech44]

It looks like you have a good start. Obviously there are other components of the bike to consider as well.

Bike is a mess. Just hoping to get it running decent cheap. Hoping to get away with this also.

[cajun31]

Don't know what real life symptoms were. Gas was gushing past every needle and seat. More gas than oil in the crankcase when I got it.

Sounds like the first order of business will be to check floats, float pins, needles and seats. You need to verify that they are set right. Larry posted a good picture of how to set them with line level. if you don't have a manual you can download one from here. Ringler.us | Manuals & Resources | Yamaha. You can also set the float levels by bending the float tab. The manual will indicate how to measure and make sure when you measure you do so with the gasket removed. Once you get that resolved then you can start looking at the jetting etc. Might want to inform your friend he will need to get his funding ready. If anything in those carbs do not have the true Mikuni emblem on them then they will need to be replaced. Mikuni has the square within the square emblem on them. Deebs has listed everything you will need. About the only thing in those cheap Chinese kits or for that matter the K&L kits found on ebay and other places are the needle seats, needles and the gaskets. By the way the gaskets need to also be checked because they can sometime protrude when installed on the inside when compressed by the bowl and impede float movement. Might be what is happening to those carbs you are working on. They can be trimmed with an Exacto knife to fit. Some don't even like to take chances on those few parts either and stick with reputable parts. I looked at the picture you posted and couldn't really make out the lettering on those main jets. Do they have the Mikuni emblem on them? You can get the bike running without those pods on them. By the way have you verified what they are and whether the lips on them impede anything when they are installed?

[autotech44]

Sounds like the first order of business will be to check floats, float pins, needles and seats. You need to verify that they are set right. Larry posted a good picture of how to set them with line level. if you don't have a manual you can download one from here. Ringler.us | Manuals & Resources | Yamaha. You can also set the float levels by bending the float tab. The manual will indicate how to measure and make sure when you measure you do so with the gasket removed. Once you get that resolved then you can start looking at the jetting etc. Might want to inform your friend he will need to get his funding ready. If anything in those carbs do not have the true Mikuni emblem on them then they will need to be replaced. Mikuni has the square within the square emblem on them. Deebs has listed everything you will need. About the only thing in those cheap Chinese kits or for that matter the K&L kits found on ebay and other places are the needle seats, needles and the gaskets. By the way the gaskets need to also be checked because they can sometime protrude when installed on the inside when compressed by the bowl and impede float movement. Might be what is happening to those carbs you are working on. They can be trimmed with an Exacto knife to fit. Some don't even like to take chances on those few parts either and stick with reputable parts. I looked at the picture you posted and couldn't really make out the lettering on those main jets. Do they have the Mikuni emblem on them? You can get the bike running without those pods on them. By the way have you verified what they are and whether the lips on them impede anything when they are installed?

Been there done that. I use the K&L kits for gaskets, needle/seat and o-rings. OEM other than that. I'm gonna set the floats at 27mm I believe is the height spec. Then I'll double check the fuel level once assembled. Always been dead on for me. The LH supplement shows 3mm below the bowl edge. I don't know if you noticed the broken float pin perch on carb 3 housing in the picture. The pin stays fixed with one so I'm gonna have go with that.

[jetmechmarty]

Bike is a mess. Just hoping to get it running decent cheap. Hoping to get away with this also.

No you won’t get away with it. That has to be repaired or the carburetor body replaced. Do you have the piece that broke off? JB has a fuel proof product if you do. I had a post welded on mine. A replacement carburetor body is your best bet if you can find one.

[autotech44]

No you won’t get away with it. That has to be repaired or the carburetor body replaced. Do you have the piece that broke off? JB has a fuel proof product if you do. I had a post welded on mine. A replacement carburetor body is your best bet if you can find one.

I was thinking about JB weld. But surprisingly with the pin istalled it stays in a fixed position having no effect on the float. The only risk is the other one breaking off. I've seen it before and it never let go.

[DEEBS11]

Add heat, petroleum, vibration and time and it will surely fail.

[DEEBS11]

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[DEEBS11]

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[autotech44]

Add heat, petroleum, vibration and time and it will surely fail.

I'll add a dab of JB weld. Can only spend so much here. Don't even know for sure the engine is good. Owner is fully aware. He broke it.

[DEEBS11]

https://www.chinookfabricationanddesign.com/carburetor-float-post-repair