Topic: Advance Mechanism springs source?

[Simon]

Hey

I was looking at my advance mechanism springs and find them a little rusted and maybe week from all those years of work on my CB400F. Took a look at my springs on my newly acquired CB175 and they look even worse.

Anybody here ever changed their advance springs? How did you manage to find new ones? Any specs to match?

I read that some have shortened the spring a bit to stiffen them up but I am afraid that with the rust, the spring would simply snap if I were to bend it to recreate the loop at the end.

Thanks guys and girls.

Simon

[tlbranth]

Can't you buy them from Honda?

look here    http://www.powersedge.com/pages/parts/viewbybrand/7/default.aspx

[Gordon]

If you're looking for new, I think you have to buy the whole advancer unit to get the springs. 

Have you tried cleaning up the springs to see what they look like once the rust is gone? 

[Simon]

Well, in the parts fiche many stores share, there is no PN for the springs alone. I can find the whole advance mechanism but I find it a little steep at $90ish for the CB175 and $40ish for the Cb400F when all I would need are 5 cent springs. Or maybe I did not search correctly on the link you posted?

I did wire brush them a little and all but one are not so bad rustwise. The one with the most rust (CB175) is pitted, I am sure it would brake if I bend it...

S.

[Gordon]

Those springs are such a specific size and spring rate that I think it would be very difficult if not impossible to find some that exactly match from an outside source.  Even a slight change in spring rate would alter the advance curve.  I say use the good ones you have and look on ebay or a local salvage yard for a decent used advance mechanism that has good springs for the ones that need replacing. 

[crazypj]

I have a few NOS Suzuki advancer springs.
They look about the same as 400/550 springs (the weights look about same as well)
 Also have some other odds and ends, could match them with CB360 advancer springs.
 Have some NOS advance units for CB93 but that would be expensive just for springs
 PM me if your interested, can't talk prices here
You can also get Yamaha ones from Mikes XS

PJ

[Simon]

PJ

Thanks for the offer. I"ll check things out at a few parts store first. You never know, sometimes they can find something like a compartimented box with pretty little springs from the good old days just waiting for a guy like me to come along... wishful thinking, I know... 

I figure that if I can find a close enough spring, I could test it's strength by attaching small weights to the end of it and measuring it's stretch and compare with the rusted ones. I would then test it on the bike with a strobe light and see if it advances correctly at say 2500 rpm. Does that sound right? The cb400F's mechanism snaps back well IMO. It's the cb175 I'm worried about. Kind of weak feel to the springs, but that's a question for the «other bikes», I know...

S.

[crazypj]

measure wire diameter and coils, same is same. (or at least close enough not to matter)

PJ