I've got 2 MOLKTS and a Miconi which is almost the same carb ...... the Miconi is lighter and has "Model in Japan" cast on the side ......
..... The MOLKTS have nothing on them ( except MOLKT ) so it seems that they're a chinese copy of a Miconi .... NONE of them are 26 mm ....... they are actually only 24 mm if you measure the venturi with vernier calipers ... only the end of the outlet bore is 26 mm .....
I bought one MOLKT on ebay from the guy who sells Pimpit bikes ....... it smells of fuel so it's been used on a bike and found to have a problem .... so he's removed it and choofed it off ... and I'm the unwary sucker who bought it ... LOL .......
But I'm most certainly not complaining since it was only cheap ...... still a bargain !!! The other MOLKT is on a brand new as yet un run DHZ Monster Pro 150R SE bike !
After reading this thread .... I pulled the MOLKT , the Miconi , a genuine VM-28 off a KX80 , and an XR80 Keihin carb apart to check for anything that was obviously different on the chinese carbs ....
The MOLKT's rubber float bowl to carb gasket was too small and was cocking up into the bowl on one side so it wasn't sealing properly and would have definitely allowed fuel to pour out of the bowl if the carb was tilted .... It would also have created an air leak which would allow fuel in the bowl to be aerated as it sloshed around .... I carefully stretched the gasket until it fitted neatly into the recess in the carb body ... so that's one OBVIOUS problem that was a simple fix ....
The gasket in the Miconi sat perfectly where it's supposed to sit and was sealing spot on ......
The first thing I noticed between the carbs is that the VM-28 and the XR80 carb both have "bells" over the main jet ..... a "bell" is a brass or plastic shroud like a cup with a hole drilled in it that goes between the main jet and the needle jet (aka emulsion tube) ..... Its purpose is to stop intermittent fuel supply to the main jet caused by the fuel being pulled away from the jet due to sloshing around in the float bowl when the bike gets shaken or moved around quickly ....... (tilted during wheel standing , landing from a jump , hitting bumps and ruts etc) ..... The symptoms of fuel slosh are annoying bogging and spluttering intermittent loss and regain of power etc ......
Stock early XR75 20 mm Keihin carbs never had the bells and neither did the SL/XL 125 22 mm Keihins that were fitted as a performance carb .... They ran perfectly on roads and relatively smooth tracks but not on rough tracks .....
In 1974 , American modifiers such as PK Racing , Ward Racing , DG etc discovered that fitting a bell over the jet solved the weird running problems ...... I took good notice of what I learnt from reading hop up articles in American Minicycle Magazine and fixed all my carbs by fitting my own bell shrouds ..... it was one of my little secrets .....
Then in later model bikes .... Honda adopted all the modifications to make the bikes run better ...... they also altered the float bowl shape and made it smaller in volume to help keep the fuel from pulling away from the main jet ....
I'd say that the MOLKTS suffer the same problems ...... and the easy fix is to buy a main jet shroud for a VM-Mikuni , make sure that the carb to bowl gasket is sitting in its recess and properly sealing , and also to make sure that the float level is set properly ...... not too high .... and not too low ......
It's best to set the float level with the fuel tank and carb off the bike ..... that way you can adjust the float tab to achieve the highest fuel level possible and tilt the carb to simulate hill climbing and wheel standing ..... making gradual alterations until you can tilt it without fuel running out from the overflow .......
I'm fairly confident that these carbs can be sorted out if set up right ....... IF the carbs WERE junk ...... the company making them would have disappeared pretty quickly .......