Started, then died, unknown cause

After a Bike has set for years with fuel in the carbs, they will be needing a through cleaning. Paying close attention to the small circuits, Pilot, Transition and Starter circuits. These will be blocked which will give you fits, until you clean the carbs properly.
Also check your float valve O-rings, where the valve seat goes into the carb body. These will be junk, replace those. The float cannot control fuel entering the bowl from bad O-rings. So flooding, incorrect fuel level is the result.

johnjones750csr wrote: ...Giving it any more than a little tiny bit of throttle results in the bike hesitating and then dying immediatly....

Would suspect a less than perfectly clean as new pilot circuit.

Carbs at hand are most likely as shown in the diagram posted by 650ed, being CV (constant vacuum) as opposed to manual slide carbs. Function of the float valves and floats are basically the same in both carb styles.

Here's one method to help clean the pilot circuit using carb cleaner spray.
Wear eye protection, because the spray always backfires. Always.



And be sure the "plugs" are fitted during re-assembly.


Good Fortune!

Be sure to check the carb holders for leaks. I suggest you try the following. Get the engine running and idle it down as low as it will idle. Spray carb cleaner around the carb holders, especially where they mate with the cylinder head. If the engine dies or seems to react to the carb cleaner, you need to replace the carb holders. Ed

bs34 is the same as the mikuni I assume? Good info, damn I might as well go find a full carb rebuild kit and take the body's down to get cleaned properly. All of this putting on and taking off is really an annoyance. Those little pipes between the carbs and the airbox are really aggrivating lol

Z1enterprises has the carb kits, the Airbox to carb boots as well as the carb holders/ intake manifolds. Not as cheap as other models but it sure makes it easier to get the carbs in and out.
www.z1enterprises.com/ItemDetails.aspx?i...80-85&item=KL18-2452

Well, I took the carbs apart again today, and found a clogged pilot jet on the right side carb. Completely clogged, of course it doesn't take much, the hole is so damn tiny. So I cleaned it out wiht a twist tie, it was just the right size to go through the hole. I'll get it all back together in a little while, all of the other orfices were clean as a whistle. Just the one clogged pilot jet. Also, I can't get the screws loose on the drains for the float bowls so I can't check the float level. I'll see what this new clean jet does. Hopefully it'll make it run a little better.

John Jones
1982 750 CSR Twin