Cylinders not working after su conversion

[madkaw]

I had the same issue and it was the float bowl fuel line was kinking.

Just a thought.

[shadesh]

The front carb's float level is still too low. Correctly setting the level can be tricky for the inexperienced. You need to bring it up another 3-4 mm, as a WAG.

so if I bring it up another 3-4mm, the float level will be a lot less than the 12mm as specified in the manual. Does that mean something else is out of sync. ? Although I might try bringing up the float a little more ..

Lets see..

[Arne]

How are you measuring the float level? I suspect that is the problem. I know from personal experience that what seems like 12mm when you have the float cover removed does not always measure correct when it's all re-installed.

To verify my levels, I generally put a clear vinyl tube on the bottom float nipple (instead of the normal tube to the bottom nozzle). Then I remove the power to the coil and crank the engine over a couple of times to fill the float bowl. (If you have an electric pump, just hot wire it for a couple of seconds.) You will now be able to see how high the fuel sits in the float bowl under operating conditions. The fuel should be 23-25 mm below the top of the float bowl when measured this way.

[shadesh]

How are you measuring the float level? I suspect that is the problem. I know from personal experience that what seems like 12mm when you have the float cover removed does not always measure correct when it's all re-installed.

To verify my levels, I generally put a clear vinyl tube on the bottom float nipple (instead of the normal tube to the bottom nozzle). Then I remove the power to the coil and crank the engine over a couple of times to fill the float bowl. (If you have an electric pump, just hot wire it for a couple of seconds.) You will now be able to see how high the fuel sits in the float bowl under operating conditions. The fuel should be 23-25 mm below the top of the float bowl when measured this way.

I use a 12 mm bolt. I turn the float bowl cover upside down and place the bolt on the float bowl cover and rest the float on the top. I then adjust the metal thingy so that it barely touches the metal pin (that opens and closes to allow fuel to flow). Does that sound correct?

I think I will try your method .. seems to be more accurate.

[Arne]

I use a 12 mm bolt. I turn the float bowl cover upside down and place the bolt on the float bowl cover and rest the float on the top. I then adjust the metal thingy so that it barely touches the metal pin (that opens and closes to allow fuel to flow). Does that sound correct?

I think I will try your method .. seems to be more accurate.

What you did is the traditional method - that even I (with years of SU experience, both Japanese and British) have problems with. Using the clear tube I was able to get them both correct in short order.

[z74z90]

Shadesh...Are you aware of this site? If not, I think you will find it very helpful.

http://www.teglerizer.com/sucarbs/techtip6.htm

[carrott]

Check carbs are properly synchronized if at Idle there is no flow through front carb then raising piston will have no effect , as they are a constant depression design it needs a negative pressure to allow the atmospheric pressure (greater) to push the fuel out the nozzle as the needle raises.

[shadesh]

Sorry fellas. I am still trying to tinker with the carbs. I thought I'd post something as I don't want you to think that all your efforts to help is going to waste.

I read through the page z74z90 recommended. Very helpful. I will update soon.