Bs38 carbs dumping gas out of intake

[Hankoldboy]

https://yamahaxs650.com/product-category/fuel-system/carb-main-jets-pilot-jets/page/3/

Ever purchased anything from this site? Wondering if it’s credible

 

[5twins]

Well yes I have, but not carb jets. They sell repops and I only use genuine Mikuni jets. That link to Niche Cycles is good, they have genuine Mikuni jets.

 

[Hankoldboy]

I’m having a hard time finding oversized jets for these carbs. It seems like it isn’t getting enough gas but when I try and adjust the air mix screw it doesn’t seem to do much of anything. Again I’m pretty new to this so I apologize for my incompetence.

 

[Hankoldboy]

I’m having a hard time finding oversized jets for these carbs. It seems like it isn’t getting enough gas but when I try and adjust the air mix screw it doesn’t seem to do much of anything. Again I’m pretty new to this so I apologize for my incompetence.

Running pod filters on it at the moment if that helps.

 

[5twins]

Adjusting the mix screw will have little, if any, effect if your float levels aren't set correctly. Larger jets are readily available. The Mikuni jets used in these carbs are very common ones. The pilots for your '79 carb set are the VM22/210 type. The stock size was 27.5 so you'll want a #30, or maybe even a #32.5.

The mains are what are called the small round type, specifically a Mikuni N102/221 type .....

Stock size in your carb set was a #135 so you'll want/need about a 140 or maybe a 142.5. Once you install the larger mains, you will need to lean the needle setting a step.

 

[arcticXS]

Running pod filters on it at the moment if that helps.

That may be the root of your carb tuning problem.....5twins must have missed that bit of info ☺.
Post some pics of your filters, side view and from the end that goes on the carb.

 

[Wilsonsk]

Ok. Here’s the verdict. The old float needles fixed the gasoline waterfall issue I was having. Bless you 5twins for that tip. I polished the old seats and needles with a q tip in the chuck of my drill dipped in brasso then cleaned everything with carb cleaner. Fixed it right up. The choke lever however was not as straight forward. The end of the lever assembly was starting bottomed out in the slot in the choke rod so it had no where to slide. If that makes sense. The pin on the choke lever that moves through the slot had no room to move. With a little grinding and a little bending I was able get that pin positioned back to where it would work properly. It’s still a little sticky but I can operate it with one hand now. 80 percent improvement. That you guys for your help. The first image is before repair second is after. Third photo is a reference for the bend I put in the choke lever to get it to work.

Now to sync them and try and get rid of as much of the popping as I can. Fixing the carb issue helped the popping but I think it may be running a bit lean now.

I bought a new choke lever from mikes, I had the same issue and solved it the same way, I ground a little off the pin and the bent both the lever and the slotted piece on the choke shaft in, towards the carb body, a little bit, now it works good.