Rough running

If the carb swap is the only change, why not replace the concentrics to see if it still runs as well as it did? There's little point in speculating on non-carb issues if the carbs are the only change.

If the concentrics work then the fault is with the new carbs. No knowledge of monoblocs so I'll defer to one of the experts on the forum.

Hope you get to the bottom of the issue.

I have the glass ended extension I use for my mono lock set up. Welcome to borrow it eliminate fuel level.

Cheers

Jon

Hi David,

Do/did these come with the infamous 'stay up' float(s)?

I had issues when I fitted one of them last year, with the bike running very rich low  down.  When checked, the float fuel level was nearly a 1/4" too high.

(Apparently, as you probably already know, the dot/pimple on  the cover is correct level.)

My issue was resolved by the simple expedient of fitting a second gasket to the cover. Not found out why as it works and isn't leaking!

I am by no means the only one who has had issues with these 'stick down' floats, so definately worth a check.

Note: For a quick check for fuel level, dont bother making a plastic window. Remove the r/h jet holder and bend the link pipe up. You will then see the fuel level in the pipe. If you have black pipe, just gently lower it until fuel starts to flow and that is your level. 

If you do make a clear cover, make sure the plastic is fuel safe - I made one last year and it lasted less than a minute before crazing and falling apart. Obviously I used the wrong sort of  plastic!

Keep us posted on what you find out. 

Regards, George. 

Hi David, It does sound like a low fuel level or a float  not being free to move. I had to rub a few thou off the little brass spacer  .I also have had trouble with floats jamming in the fully down position .  

Hi, are you sure it is not the Rita unit with a transistor gone to earth? Not unknown to go suddenly.

... with making a clear float chamber cover is that it may mask the original problem which could be related to the standard cover (eg the spacer as mentioned by others). It's easy enough to make a level indicator using some clear tube from the pilot jet (or by modifying a spare main jet cover like this).