Your Rochester can be rebuilt to run great. Find a carb shop that has been around for a while - they'll be familiar with the carb. I have had several of the Rochesters rebuilt by a carb shop in town and they work great! This carb shop was even able to rebuild one of the Hitachi (original) carbs without any problem.

Are there rebuild kits?  If so, please give the kit or part number and manufacturer for both the Rochester and Hitachi.

I know ther is a rebuild kit for the Rochester available here, but I don't know the part number. I leave the carb stuff up to the carb experts - my carb shop.

 

There is not a kit available for the Hitachi here. Once heard you could get one from OZ, it was an aftermarket kit. Never could track it down there. But, when I took my Hitachi in to my carb shop they were able to match up enough parts from other Hitachi kits to rebuild the thing. Like I said - I leave that stuff up to the experts. If you've rebuilt a gazillion carbs it's a piece of cake.

 

Here is the info on the Hitachi kit:

http://www.motospecs.com.au/fuelmiser.html

these are the people that do the kits
The kit number for a g60 hitachi carb is ht-410