SOHC.co.uk Forums > CB500/550

Speedometer drive

<< < (3/3)

McCabe-Thiele (Ted):
On my cars with poor stem seals or worn  guides there was a simple test I used.

When the engine was hot after a run,switch off, leave the engine for 20-30 minutes to cool a little.
Then start the engine again & blip the throttle. A puff of blue smoke indicated there was a problem.

Skoti:

--- Quote from: JezzaPeach on September 11, 2026, 12:09:38 PM ---Many thanks all. Standard tyres, it sounds like it’s pretty normal. I thought I was getting 50 mpg and on a short test vs Google maps it’s more like 45 mpg. So I’ll do a longer test at steady cruising speed and hopefully that will give an equivalent better consumption nearer say 50mpg (1972 CB500/4) my plugs are quite sooty, partly due to a little oil consumption but I was wondering if it’s rich due to needle/jet wear and if it’s worth, as a test, moving say one needle clip from the current middle notch up one to see if it helps.

--- End quote ---

For me sooty plugs and bad fuel consumption usually means worn needle jets, they last around 15,000 miles on my CB750F1.
But they always wear oval, so lowering the needles is not the best solution.


A new set always brings better fuel consumption and performance with a punch.


Genuine Honda brass ware is best

https://www.cmsnl.com/en-gb/honda-cb500k1-four-england_model14660/needle-set-jet_16012323004/


Pattern also available

https://www.davidsilverspares.co.uk/parts/by-part-number/partnumber_16012323004P


Good luck


 

JezzaPeach:
Many thanks Skoti 👍

Navigation

[0] Message Index

[*] Previous page