Hello everyone!
I recently purchased a used 77 CB750K with 20k on the Odometer. Despite not being anywhere near as original as I would have liked I am really happy with the purchase.
My goals before spring are to get the bike titled, tagged as an antique and finally get the bike running perfectly. Given that this is my first bike I am going to keep it as is for the spring/summer and then look into completely tearing the bike down next winter.
As you can see in the picture it has an aftermarket exhaust and pod filters. It also has Mikuni carbs. It obviously also has the typical cafe seat, handle bars and a couple other cosmetic changes.
The bike runs but not perfect. The PO informed me that the carbs need to be cleaned. So that is the first order of business. Also, this is where I would like the first bit of advice about the best route to take.
I purchased Mark Paris' My CB750 Book which deals mostly with the pre-77 CB750, but the differences are so small from what I understand that I saw no reason to not have this book on hand. I read the carb section of the book in its entirety. I have also done a bit of research here on the forums. I kept coming across threads about people putting pod filters on their carbs and for a few reasons produced inconsistencies in A/F ratios across different throttle positions. Generally it seemed jetting the carbs to 130s fixed the problem but not always. I also noticed that this occurred mostly on pre-77 CB750s.
So I need advice on what route to take. I have the original airbox and carbs. On the bike now are the pod filters and Mikuni carbs. Should I keep the Mikuni carbs and pod filters or put back on the original airbox and carbs? I have read in the threads here that the original 77-78 carbs are "terrible" and I have heard that they are great and much easier to tune than pre-77. Completely contradictory statements
. I also know they have accelerator pumps, and I am getting ready to do more research on what that actually is and what that means for making this decision.
Any advice on this would very much be appreciated. My goal is to have the bike be very consistent and run well around town and at freeway speeds. I have no plans to race. If the Mikuni carbs and pod filters will provide a performance increase without cost to it running properly and without increased risk of damage to the bike I would like to keep them on.
Thanks!