Topic: CB400F Carburetor Choke Linkage Spring And Ball Bearing Size

[RickB]

Hi guys,

So I've been battling to replace the choke locking spring and ball bearing for the carburetors. It's a ball bearing that sits in the end of a spring (like on the kick starter) that is pressed into a hole in choke linkage arm to hold the choke off.

The spring and ball bearing circled below aren't listed in the part fiche, so I don't know their sizes. I've been guessing but it's not going well. I found that the spring from a Bic four-pen is kinda' right and a 3.5mm bearing sort of works, but it's not great. Does anyone know these sizes, know where to get them or have these parts?







Thanks,
Rick.

[grant301277]

hey mate not sure if it would be the same but i have robbed one out of a broken kill switch ( honda off,on,off style ) for the choke linkage on a set of mikuni carbs .maybe the same size ??

[-CB-Jamie-]

Rick, just measured the ball bearing in a spare set of carbs i have and it's 4mm, so that 3.5mm one you have is pretty close. The 3.5mm bearing should work ok, maybe the spring from the pen isn't strong enough??

Jamie

[RickB]

Thanks guys.

Jamie, that is great you were able to measure the stock bearing. Thank you. You don't have a stock spring to measure do you? The width, length and your estimate on strength I guess. That is the hard part to find actually. The spring I'm using is no way near stiff enough I think.

Thanks again guy,

Rick.

[-CB-Jamie-]

Ya I just measured it there and it's 7mm long by 3mm thick and actually quite strong for the size of it. It's nearly a struggle to push the spring together between your thumb and finger. Hope this helps

[RickB]

Jamie,

You are a life saver, thanks mate!

Now I have to find somewhere that sells such a small spring. A hobby shop or somewhere that sells remote control cars I think.

Rick.