This Listing is for a pair of Custom Assembled Lectron Powerjet Carbs for your RD250/350LC , RD250/400 aircooled. We would use 34mm HV carbs usually for the application. 

Before buying please contact me with the spec of your particular bike. The carbs will be factory assembled in Texas to suit the particular application. This takes around 10 working days usually. For common applications we have them in stock in the UK, so turnaround is quicker. 

We are the european distributor for Lectron Fuel Systems Inc.