Mikuni 34mm

Thankyou very much for diagram,it sure helps.

mopguy wrote: Okay, so nobody can help me yet, however I was looking at the BS34mm rebiuld tutorial and saw in the pictures of a slide with the diaphgram at the bottom and jet needle at the top,that means jet needle is fastened in the slide, mine is just placed in there, if you turn slide upside down, the needle falls out. Question is, are the needles fastened to the slides in this carburetor, because if they are, I am missing the pieces to fasten the needle, and that means the previous owner was in here, and probably why I am having difficulties, also if I spray carb cleaner in from main jet where should the cleaner come out?.

The BS34 carb that is the Factory Original on your bike will have the needle with a single clip in one grove. It goes into the slide, than the round plastic piece which holds the needle down when the spring is in place. So you have the slide, needle with clip, spring then cover. No other small spring, or spacer on the OEM BS34. Now if it has say Suzuki BS34 carbs instead, so the hole rack was changed out, then it would have the other small spring which lifts the needle up off of the bottom of the slide. You should not have that set up unless the carb rack was replaced.
If you spray carb cleaner into the main jet hole, it should come out of a few places. The first would be the needle Jet orifice at the venturi. Then the main Air Bleed, as well as the Pilot Jet and Slow Air Bleed, and the mixture screw. There are connecting circuits in that carb to the Main Jet.

Thankyou motorhead, I have the all of the parts and will now re assemled it properly.

Still wont start, bowls have fuel, carb bodies are clean, will a bad petcock prevent bike from starting? I dont know what else to think.

The Suzuki carbs will also have the small snap ring that holds the whole works in there too

I am at a point where I am going to throw these carbs in the garbage. I have done everything and have nothing to show for it.

After a failed start-up attempt, are the spark plug tips wet with fuel, which would indicate that some fuel mixture is actually being drawn into the combustion chambers?

If the spark plug tips remain dry, that means no fuel mixture, which means no combustion.


Here's a diagram showing how to spray carb cleaner to assure it's exiting into the carb throat.

This test assures that the tiny passageway into the pilot circuit is clear


On carbs fitted with plugs over end of pilot jets, the plugs are essential.





Good Fortune!

Will be spraying carb cleaner as directed in the morning, I hope this solves the problem. Thanksyou Patton.

On later model BS34 carb that eliminated the plug at end of pilot jet (and I believe also eliminated the tiny passageway), may spray carb cleaner directly into the pilot jet to assure the spray exits into the carb bore.

The objective, of course, as with any carburetor, is assuring that fuel mixture will be getting into the carb bore to be sucked into the combustion chamber.

Good Fortune!

I have been busy painting the house, so I gave the carbs a little break, soaked them again overnight in pinesol and passages are still blocked. I finally went to an auto parts store and ordered a gallon of carburetor and cold parts cleaner, I picked up solution today as they dont carry it in stock. It is labebeled KLEEN FLO and this stuff smells nasty!, I put one carb in there to soak overnight, will let you know results when finished. Has anyone here used KLEEN FLO?

I have soaked two carburetors so far in this nasty solution called KLEEN FLO and it is made here in Canada for industrial use and available in the USA as well, and I cant believe the crap that came out of them after an overnight soak and a thorough wash with varsol, and compressed air. , I must have cleaned my carbs using pinesol and other cleaning solutions at least six times and not to mention the amount of aerosol carb cleaners that I sprayed in them, and they were still plugged up, I wonder how long these carbs sat for before I purchased them? I probably drove Patton and all the other members crazy with all the questions that I have asked. Anyhow if you need to clean your carbs properly, dont waste your time like I did trying to save a buck here and there, by using green products,these green cleaners may be okay on slightly dirty carbs,but if yours are dirty!!!! and I mean dirty!!!,go to an auto parts supplier and get this product,its not cheap, but money is not everything! If you use this product,make sure to remove all plastic and rubber pieces out, including butterly seals, as they will definetly be damaged by the solution, or you can buy new butterfly seals and replace them.