#4 dumping gas

[thewiz]

I believe your carbs are

BS 34 III .... earlier models E, F, and SF were BS 34 II. Different animal.

[81xsproject]

I thought the FJ carbs were the type III's...?

[XSPastor]

The Clymer manual says that the 1980 SG and LG have Mikuni BS34-III 3J6-00 carbs. The 1980 G has BS34-III 3H5-00 carbs.

Tim

[DiverRay]

Tim,
Yamaha phased in the carbs.... Some of the early builds had the older carbs, and then they all had the "new" carbs by the end of the model year. It is possible to have the early BS 34 II on the SG.

[XSPastor]

Ahhhh. Thanks, Ray!

Tim

[SanDiegoMike]

Is the model # stamped on the carb body somewhere, or is there a difference in the design that let's you know which carb you're dealing with?

[John]

The quickest way to tell them apart is the 80-81 carbs have four orifices around the carb inlet, the 80-81's had thre, and the 78-79's had two sets of T fittings between the carbs. The upper set is for the bowl vents, the lower set is the fuel inlet.

[thewiz]

Pretty certain ...

You have the III's... no vent hose that looks like the fuel line between 1&2 carb and 3&4, right? ....

I'm on my way to wally world, out near you give me a call if you're home and I'll take a peek before the sun goes down.

[SanDiegoMike]

Back together!

And running pretty good from what I can tell so far. Idle is still just a bit rough, but it's steady...no more stalling at intersections, and most importantly, no more of that surging that I was getting before. I still need to get the sync done (Soccer4M, I'll be calling you soon!), and I'm really curious to see how my mileage will be affected. It seems that I have to apply a lot LESS throttle now than before to get up to and maintain speed. Of course, that could also be because I've been riding my daughter's bike for the last week, and it has a much more difficult time hauling my largeness around!