Mikuni Bs34 Carburetor Manual

The XS650 Garage Carburetor Guide Introduction This manual has been prepared by Grizld1 ( aka Dick Russell, Yamaha 650 Society. OEM Carbs, BS38 (70-79) and BS34.

Can anyone please provide me a detailed diagram showing ALL the air and fuel circuits/paths for my BS34 carbs (1982 KZ1000P1)? I want to clean them and make sure all passages are open; for example, there are three tiny holes by the butterfly which I'll try to stick some fishing line through, but it would be nice to know where it's suppose to come out.

0.6.3: Updated Tor to 0.2.4.22. 0.6.5: Updated Tor to 0.2.4.24. 0.6.2: Updated Tor to 0.2.4.21. 0.6.4: Updated Tor to 0.2.4.23.

I downloaded but don't know if it's my carb. And I have two service manuals but they seem to show generic/major paths only.

Teksti dlya izucheniya russkogo yazika dlya nachinayuschih. Please or to join the conversation. May I suggest going ahead & doing the complete teardown so that the carb bodies can be soaked.

Doing so should take care of any problem orifices that might be plugged. Doing so isn't that bad. A lot of the same thing is done four times & most stuff only goes back together one way. I did a set of VM carbs for the first time several years ago, and it really seemed quite easy to me.

Instead of bothering w going back-n-forth referencing the manual, I just used my eyeballs & common sense to get them apart. A clean work area is helpful & 4 small parts containers are goood for keeping things organized. Please or to join the conversation. JMKZHI wrote: May I suggest going ahead & doing the complete teardown so that the carb bodies can be soaked. Doing so should take care of any problem orifices that might be plugged. Doing so isn't that bad.

A lot of the same thing is done four times & most stuff only goes back together one way. I did a set of VM carbs for the first time several years ago, and it really seemed quite easy to me.

Instead of bothering w going back-n-forth referencing the manual, I just used my eyeballs & common sense to get them apart. A clean work area is helpful & 4 small parts containers are good for keeping things organized.The reason I'm taking the carbs off again (just had them off) is that I didn't put back the pilot jet plugs; but the bike started great and ran great.until the combination of over 1/2 throttle over 4,000 rpm; then it would start coughing and slow down; if I backed off the throttle it would be fine up to red-line. So I'm going to put the jet plugs back (when they arrive on Thursday), but I figured I would do are more thorough cleaning job; however, in that the bike ran pretty good aside from what I think is the plug issue, I'm not looking to max out on the tear down; mistake?

Please or to join the conversation. There is a default setting that I'm not certain of. You can start at 1 1/2 turns out to begin tuning. If the float heights are set properly and everything is clean, the # of turns should be very close. With the bike good and hot, and carbs synced properly.

Turn ALL THE PILOT SCREWS either in or out 1/2 turn and listen to the idle. The idle should noticably rise or fall.

Continue turning if the idle rises, turn the other way if it falls. The idea is to find the spot at which the idle is highest. Then, turn each one individually 1/4 turn either in or out and listen. Try to find the spot at which the idle is highest again. They should be very close, and if no audible change is detected at this point, your done! This will assist cold starting some with the BS34s.

Thanks for the diagram and directions on setting up the pilot jet screws; I didn't realize the part about turning all the screws the same initially, so that will help. On the diagram, it doesn't seem to show it, but when I was cleaning the carbs with the tops off and the slide/diaphragms out, I noticed that opening the enrichener opens a wide port on the outside of the carb (sorry, I didn't think to get a picture); this, I believe, causes the slides to drop down to help with cold starting (although I'm not sure how that helps); when I was testing to see if the vacuum would hold the slides open (by pushing the slides up and holding my finger over the horizontal air slot), the slides would fall immediately if the enrichener was open. Seems strange that there would be an unfiltered air pathway into the engine, albeit only when the enrichener is open, and then it has to go thru the small hole at the bottom of the slide. Please or to join the conversation.