Topic: Re-jetting help after engine rebuild and modification

[Diegoz89]

Hi.
I need some little help in carb tuning after my Honda CB500 k2 '76 engine rebuild and modification.

I will summarize the works done on the engine:

-cylinder re-bore +2.50 mm
-new piston diameter 58.50 mm (Daytona Japan manufacturer, it will bring to approx 550 cm3)
-other restoration works that does not affect carburetor tuning


I want to run these filter setup:

- stock Honda airbox + DNA filter via the following adaptor:
https://www.classic-bike-parts.de/Resto-mod-Honda-CB500-550-Four-Adapter-Kit-Airbox-Luftfilterkasten


Lastly, this is my exhaust setup:

-Marving 4 into 1 open  pipes.

As per the above configuration I have considered the following carb setup:
-carb floating set to 22mm;
-idle jet #40 jet (stock value);
-main jet set to #100;
-needle raised by a notch;

Please, any suggestion is welcome.

Thank you all.
Diego

[willbird]

That is an interesting looking filter setup :-). First look I have had at that the original 500/550 did in that respect.

[BomberMann650]

The airbox filter adapter is a legit mod.

Could probably go 2 sizes bigger in the jetting and have a happy running 550 with that increased airflow.