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Toko_Jo:
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--- Quote from: McCabe-Thiele (Ted) on March 21, 2025, 06:31:46 PM ---The manual I looked at CB450 KO shows no spring on the carbs tops.

--- End quote ---

Oddjob:
Anyone notice the last paragraph, out for richer, in for weaker but is contrary to normal Honda practice, meaning it’s normally in for richer and out for weaker. Exactly what we all, well most of us, thought.

mo goldie:
Hi all just and update again,

I took the tops off the carbs today and noticed that the left kept getting stuck in the top hat so after cleaning and a bit of polish they both now fall up and down freely with the springs on and off, one thing I did Not say is the springs that I have are honda but from anther bike as could Not get the ones that Honda did for the upgrade kit for the Bomber,

So if anyone has got any of the right ones part Number 6186-283-305 if they know what the lengths of them are as the ones that I have are 8cm long, they were 12cm long but I cut them down as they were far to strong to push up on the piston so I cut them down to counter act that. so if you know the true length I think that will help.

K2-K6:
Hope you're well after hospital trip.

Ah ha, the springs are definitely suspect then.

Cutting them actually increases the spring strength, but reduces preload. Both of which you don't want in this situation.

Definitely try without them then, and would likely give some credence to your running observation of rich mixture (from having the spring too strong) it fundamentally alters the whole mixture landscape.

In effect, a stronger spring changes the vacuum under the airslide (by altering balance equation above and below) to suck too much fuel through the main jet, irrespective of it's size. Usually you'll get very quick response when you wind it on, even under load, but over fuelling that'll do for your oil by diluting it through washing past the piston rings the excess and unburnt fuel.

Interesting to here any significant change in response without the springs.

Toko_Jo:
Spring Spec. for  16186-283-305

Spring Rate 1.3 gm/mm

Free length 71 mm

Wire size 0.55mm diameter.

Outside Diameter 17 mm

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