I have gotten the M159 mostly back together and tried to get it start up (borrowed petcock off of M80 and fixed the throttle with epoxy and and a sqaure nut to act as a throttle stop). I did start after many kicks!!! But there was fuel everywhere dripping quickly out of the bottom of the carb. I did disassemble and "clean the carb" when I was going through the bike a few months ago but it was pretty clean to start with the photos are from the intial cleaning.

What would cause the fuel to drip out?

Probably the float or it's valve. The Bings can be prone to this.

My own 199A once started to do this and first I knew about it was once when I had left the fuel on, came back to the bike and fuel was everywhere including half filling the crankcase in my case I kid you not!!

Wayne.....

yeah probably the float needle not sealing

OK I will pull the carb and clean and make sure the valve is seating well thanks for the advice.

Fergus did you find a bike yet?

Sunny

Went through this after receiving my bike. A slight adjustment of the float heigh lower solved it. The beauty of the Bing is that you can remove the bowl by simply flicking the bowl clip off. No need to remove the carb or rotate it. Wish my other Mikuni equipped bikes were this tuning friendly.

I'm afraid not, it seems these Buls are few and far between here on the island. there is still the m80 in cobble hill I may go look at. He is asking $1250 the way it sits or $800 with all the goodies taken off of it. Which I would have to buy anyway so I would be right back at $1250 or more. I would really like to get a later model 350 like your 159. I would go for a m80 if it was the right deal though, to me $1250 seems high. I may go look at it and ask him if he would take $800 the way it sits. I may consider a different make /model if a good deal comes up . Maybe a yamaha ty250, honda tl250, montassa cota 247/348/349. I missed a kawasaki kt250 a while back on used vic it was $150 and advertised all of an hour! By the time I emailed the guy it was gone. I really want a bultaco if I can find one though. It seems that there are three of use looking for them on the island. Some guy up in parksville, you and myself. I guess I'll just have to be patient. Your 159 looks like its really coming together. Is your m80 done?

Edited November 16, 200916 yr by fergie

Floats can become sinks on the Bing model 84. You can check it by just putting the float in a container of gas. It should not sink to the bottom. I bought a float from Bing USA for Spanish Bing #12301/1. I think the newer floats are black. The part number was 350300 $15.78. http://www.bingcarburetor.com/

On another note, I also bought a slide that did not have the same cut-away as the original. Bike ran very rich through the mid range and ended up changing back to the original worn slide.

Bob

I have gotten the M159 mostly back together and tried to get it start up (borrowed petcock off of M80 and fixed the throttle with epoxy and and a sqaure nut to act as a throttle stop). I did start after many kicks!!! But there was fuel everywhere dripping quickly out of the bottom of the carb. I did disassemble and "clean the carb" when I was going through the bike a few months ago but it was pretty clean to start with the photos are from the intial cleaning.

What would cause the fuel to drip out?

Its more likely by the look of it your float bowl gasket as it seems well past its use by date!

or it will be the fuel float valve.

I would replace both.

While your at it check the slide , needle and jets too.