Another "help me get my bike running" thread

[sleepygreen]

I bought a 78 xs650 that has new points, coils, wires, plugs, valves and chain check out good, and finally new mikuni vm34 carbs. I tried using my friends stock carbs and the bike runs. With the vm's i can only get it to start for a second with starting fluid, but dies once the starting fluid has been used up (about a second or two). The carbs have the following specs:

Main jets: 180 (have also tried 195)
Pilot jets: 30 (have also tried 20)
Needle: 6f9 set on center clip groove
Needle jet: p-5
Floats set to 25mm i think (whatever the manual said when i was doing it)
Air Jets removed

I have tried several different settings on both air and idle screws and just cant get it running, new gas and i know the bowls are filling properly. When i have had it running i have to give it a little throttle and it sputters and backfires quite a bit.

I would appreciate any suggestions.

 

[retiredgentleman]

Welcome;

You need to read and educate yourself on these VM carbs. Click on "Tech" at top of page....................go down to Carbs...........manuals. Read everything on the VM's before asking more questions.

 

[gggGary]

Nice of you to list jet sizes but it's meaningless without knowing how the bike is set up for exhaust, air cleaners etc. But it should start and run anyways. something is wrong with the basic carb set up. A proper bench synch and a real fuel level float height check would be tops on my list.